Student shares his UK container home dissertation research with Adaptainer.
House prices are rising and becoming unaffordable to many in the UK – so could a shipping container home be a cheaper alternative?
Owen Connolly, a student from the University of Westminster explored this and many other interesting questions in a dissertation.
After Owen contacted Adaptainer to help him with research we asked if he’d let us share the final paper with you.
Gladly he agreed and you can read it here.
The Viability of using Adapted Shipping Containers for Permanent Accommodation to help meet the need for Low Cost Housing in London.
Owen Connolly – University of Westminster School of Architecture and the Built Environment Department of Property and Construction.
The demand for low cost housing in London is not being met by the supply of new build homes. Following the 2007/08 recession developers have focused on the provision of high end homes, further reducing the potential supply of affordable and lower mainstream homes for those with incomes of less than £50,000.
The demand for this type of housing in London has been estimated at 28,500 per year. There are examples in the UK of shipping containers having been adapted for other uses including the provision of temporary and hostel accommodation. When used in this way they are known as Intermodal Steel Building Units (ISBU). ISBUs have the potential to provide a cost effective and speedy alternative to traditional construction. The characteristics of ISBUs provide several advantages that lead to considerable cost savings in the region of 25 – 40% compared to traditional construction methods.
If ISBUs were more widely used, some of the difficulties faced in seeking planning permission and meeting the UK Building Regulations would be overcome allowing for this type of construction to greatly contribute to the supply of low cost housing in the Capital
Part 1: Introduction.
The adoption of shipping containers for a wider variety of uses has burgeoned and now they have been adapted as, theatres, swimming pools, bars, emergency hospitals and market stalls (Marine Insight 2013). However, their use as residential accommodation appears to have been limited to either high-end statement designer homes or temporary homeless and student rented accommodation. There seems to have been little examination of developing them for widespread owner-occupation.
The London “housing crisis” has been widely discussed, regularly reported on by the media and continually resurfacing in political debates. In fact, “the UK’s housing shortage [is] a key issue and battleground in the general election” this year (Blackburn, 2015) and in the Greater London Authority’s (GLA) 2014 Talk London Survey, housing topped the list of most important issues for Londoners, with 87% believing that more housing is needed (GLA, 2015). However, despite all the coverage it receives the issue remains unresolved.
This dissertation studies whether the characteristics of recycled shipping containers and their minimal use of land area make them an appropriate and viable option for speedy and cheap construction. It considers whether they might help close the gap between supply and demand for homes in the Capital.
The existing housing shortage in London is exacerbated by the rate at which the Capital’s population continues to grow. An increased birth rate and an ageing population (‘natural change’ (ONS, 2013)) are the primary factors affecting population growth. The Greater London Authority (GLA) predicted that in the first week of 2015 (commencing 6th January) the population would finally surpass London’s peak population in 1939. (Citymetric, 2014)
The 2011 Census found that London’s population was 8,173,941 (WPR, 2014). It is predicted to increase by a further million by 2021 and hit 10 million by 2030. (London First, 2014)
Whilst demand for housing within the capital continues to grow rapidly, supply has been left behind creating an ever increasing disparity between the two.
The Mayor of London has increased the London house building target from 32,000 to 42,000 per annum (London First, 2013).
Savills (2013), CBRE (2014) and the GLA (2013), all estimate that the Capital requires in excess of 50,000 new homes per annum to meet the housing need. The target figure for 2014 was not met, only 18,380 new homes were completed, and alarmingly London has failed to meet the housing target every year since the 1970s.
The types of homes currently being developed in terms of type, size and quality are not addressing the largest shortfall in the market. The increase in demand is expected to be mainly “one-person households (projected to rise by 160,000 by 2031) and couple households (projected to rise by almost 480,000).” (GLA, 2013)
Savills (2013), identifies the need for an additional 50,000 homes a year, and that, of these homes, 28,500 would be classified as ‘lower mainstream’ or ‘affordable’ homes. These are properties valued at less than £450 per square foot (psf) and affordable to households on incomes of up to £50,000.
This demand becomes obvious when taking into consideration the fact that 70% of London’s households have an income of less that £50,000 per annum.
Although this is where the greatest need for homes lies, it is the area of the market with the greatest shortfall, 15,000 per annum approximately.
Due to the lack of supply, property prices within the Capital are at a premium. The cost of the average house is approximately 16 times the average salary, a stark difference to 1939, when it was only three times. (Citymetric, 2014)
Additionally, the level of mortgage lending has dropped considerably. In the five year period between 2007 and 2012 the amount of money being lent to buyers more than halved, dropping from £183bn down to £73bn. The owner-occupied share of the market is set to drop by at least 10%, to approximately 40% by 2025. (GLA, 2012)
Not only must consumers navigate a more competitive market and face the increasingly difficult obstacle of securing a mortgage, but there is also evidence to show that the space standards of new homes on the market are shrinking. New build homes in the UK are now, on average, 9m2 smaller than the average UK home (RIBA, 2011).
London’s prospective buyers for the next two decades face market scarcity, inadequately sized homes and high prices, which will see many more consumers resorting to the private rented sector.
Innovative solutions to meeting housing demand in London need to be found. What the Londoner with an average income needs is a ‘lower mainstream’ home of sufficient size, built quickly for a reasonable cost, available at a realistic price. The 70% of average to low income households need to be able to obtain a mortgage and enter the property market as owner-occupiers if that is their aspiration (96% of the city’s inhabitants who are not yet on the property ladder wish to be (Rightmove, 2013).
One of the key obstacles standing in the way of development is the availability of land to developers and how land that is acquired is subsequently used. Publicly owned land is slowly being released but a large proportion of that land has ended up being land-banked for future development. (GLA, 2012)
One of the solutions identified by the Mayor of London (GLA, 2014) has been intensification of housing i.e vastly increasing the density of housing on available land or through the regeneration of existing housing sites.
The focus of innovative solutions to help address the London housing crisis has more recently been around funding and release of land. In terms of speed of development off-site construction and timber framed buildings have been used, but little in the way of alternative radical methods of construction, such as recycled shipping containers, has been explored.
To understand the viability of using shipping containers for permanent accommodation to help meet the growing need for low cost housing (valued at less than £450 psf) in London.
1.Understand the current housing need within the Capital (London) that might be met by the use of converted shipping containers.
2.Research how shipping containers have been adapted and used for other purposes.
3.Identify the advantages and constraints associated with using shipping containers for providing permanent accommodation and in their construction.
4.Discuss the cost implications associated with adopting shipping containers for the purpose of housing.
5.Identify issues affecting end users, including thermal comfort, security and noise transference.
Is there unmet demand for low cost housing within the Capital?
Is there evidence that shipping containers have been successfully adapted for other purposes?
What have been the general advantages and barriers faced when using shipping containers for uses other than their original purpose?
Are there any barriers specific to converting shipping containers for the provision of residential accommodation?
Does the cost of converting shipping containers to meet the key requirements of a dwelling make them a lower cost alternative to more traditional construction methods (for one and two bedroom homes)?
Are end users satisfied with this method of construction (for example, in terms of noise transmission, thermal comfort and utility costs)?
Part 2: Literature Review
Scope of Chapter
This chapter looks at available literature that provides an understanding of the housing market in London and an insight into the current housing need within the Capital city that might be met by the provision of homes constructed using shipping containers. It also reviews and appraises available literature that provides information on how shipping containers have been adapted for other purposes and the advantages and disadvantages that may be relevant to their use as affordable housing.
The Demand for and Supply of Housing in London
Several sources, including The National Housing Federation (2014), RIBA (2011), London First (2013). Savills (2013), CBRE (2014) and the GLA (2013) have produced reports and articles concerning the existence and extent of the London housing crisis. In recent years a considerable amount of this published material analysing the London housing market has been reported in the news media.
Savills (2013), one of the world’s largest real estate firms, states that with a population exceeding 8 million, expected to increase by a further million by 2021, London’s housing market will continue to see demand grow. The demand for new homes within the Capital is estimated to be 50,000 per annum. Of that figure, an estimated 28,500 homes would be classified as ‘affordable housing’ or ‘lower mainstream;’ these are properties that would be valued at less than £450 per square foot (psf) and affordable to households on incomes of up to £50,000. These are needed as Savills report that 70% of London households have an income of less than £50,000 and in fact the median household income stands at £35,700 (Manns, 2015).
Although this is the demographic with the greatest housing demand, it is also experiencing the greatest shortfall of homes with 15,000 less units per annum being built than required.
Figures released by the GLA show the scale of the under-provision of affordable housing, with only 6,592 “affordable” homes built in the year 2013/14 – 28% of new housing in the Greater London area – this is the lowest ratio of affordable vs. conventional new build homes since 2005/06 (24%) (Spurr, 2015).
Savills (2013) highlights that, by contrast, the market for properties valued at greater than £1000 psf is at risk of market saturation. The onset of the recession in 2008 saw private developers switch their focus to delivering high specification properties for high net worth individuals (HNWIs) who were less affected by the financial crisis.
To tackle the housing shortage the Mayor’s Office recently increased the annual new build target for London from 32,000 to 42,000, although this target ought to be closer to 50,000 (Manns, 2015). However, this is of little consequence when the original new build target has not been met since the 1970s.
The housing shortage is often blamed on political failures but the London Borough’s have actually permitted the construction of 58,000 new homes each year, between the period 2004 and 2012. But the reality is that the average number of homes built year on year in the same period was only 24,700 (Manns, 2015).
This indicates that the problem has less to do with politics and is more rooted in the industry’s inability to deliver schemes quickly enough. Therefore faster means of construction, such as the use of adapted shipping containers, could be fully utilised in order to close the gap between supply and demand.
The Affordability of Housing in London
Savills (2013) assessment of differing market segments found that a typical ‘lower mainstream’ home would be a 2 bed flat costing £280,000. The average deposit required to secure a mortgage within the capital was a little over £60,000. This reflects the Office of National Statistics (2013) findings that, nationally, the average first-time buyer needs a deposit equal to 22% of the desired property’s market value.
A year on from Savills report, LSL Property Services plc (2014) produced a report focussing on first time buyers. LSL confirmed the demand for similar housing. The average first time buyer was spending £272,183. However, they reported deposits being even more extreme, at £71,309, more than twice the average deposit in the rest of the South-East.
Today, an individual earning the average London wage would be unable to secure a mortgage within the capital without an unrealistic deposit. House prices in London have now grown to be on average 14 times greater than the average salary, which means that today, only individuals earning over £100,000 pa can afford a typical 80% mortgage within the capital (NHF, 2014). The City Link research cited above reported a similar but higher figure of 16 times the average salary.
The demand for affordable homes is strong, 96% of the Capital’s inhabitants who are not yet on the property ladder wish to be. The large shortfall of ‘lower mainstream’ homes is clearly felt by the public with only 19% of the 57% saving for a deposit, believing they will ever reach their target. (Rightmove, 2013)
This inability to join the property ladder is echoed by the Office of National Statistics (2014) which showed that in 2013, 49% of 20 – 24 year olds in the UK still lived with their parents; and the average London first-time buyer was aged 32; in the rest of the UK, the average first-time buyer was 29. LSL Property Services plc (2014)
The Size of Housing in London
For those Londoners who are able to afford a property, the available product has changed over the years. UK new build homes are on average 9m2 smaller than the average UK home and are the smallest in Western Europe (RIBA, 2011). RIBA identified three key factors that prospective buyers/renters look for when viewing a house.
- sufficient outside space (49%) 2. sufficient room size (42%) 3. proximity to local amenities (42%)
RIBA found that 31% of those surveyed would not move into a house built within the last 10 years (since 2001); the key reasons being a lack of outside space and rooms being too small. However, this indicates that around 70% are willing to accept smaller space standards in order to obtain a home.
The reason for the UK’s shrinking homes can be traced back to the abolition of the minimum home space standards in 1980, originally introduced in 1961 by the Parker Morris Committee in their “Homes for Today & Tomorrow.” It was thought at the time that removing these standards would allow the market to adapt to changing consumer demands providing the most appropriate homes for the nation.
What has resulted is a progressive trend by developers of providing smaller homes. This is demonstrated by a decrease in bed spaces over a ten year period between 1994 and 2004, where previously 92% of one bedroom homes had space for two people; by 2004 this had dropped to 80%. (Joseph Rowntree Foundation, 2004)
This trend is counter intuitive as the greatest increase in London’s housing demand is expected to be couple households with an increase of 480,000 by 2031, followed by 160,000 one-person households (GLA, 2013). Therefore, not only is there a shortage of new homes in the Capital, but those that are being built are not necessarily suitable for the market.
This disparity between developers’ supply and the consumers’ demand for space is seen in the 2011 Census that showed that nationally, 28% of sole occupants were living in a one bedroom home. The remaining 72% were living in properties with two or more bedrooms, and were therefore living in under-occupied properties. (Although it should be noted that this statistic is somewhat skewed by individuals who choose to under occupy, for example, because they are parents with part-time custody of children or widowed retirees etc.) (ONS, 2014)
The GLA has introduced minimum space requirements, which apply to both public and private financed homes, in an attempt to realign supply with demand. i.e. one person flats can be no smaller than 37m2, whereas two person, one bedroom flats must be at least 50m2. (RIBA, 2011)
The Availability of Land in London
One of the key obstacles standing in the way of development is the availability of land to developers and how land that is acquired is subsequently used. Of the publicly owned land that has been made available, 45% has been sold to non-developers for the purpose of land banking as an investment (GLA, 2012).
The Homes and Communities Agency took over responsibility for the EP National Land Use Database (NLUD) for London, a database where London Boroughs record brownfield sites, and has included sites to a smaller threshold of 0.1 hectares and above.
The database records over 2,000 sites across London, equivalent to more than 2% of the land in Greater London (an increase of over 1,000 sites than recorded on the previous system) (GLA, 2014).
This demonstrates that if a way can be found of using smaller sites for affordable homes, more opportunities for meeting the demand for low cost housing would be available.
How Shipping Containers are Currently Used
Characteristics of a Shipping Container
ISO shipping containers were first produced in 1970; named after the International Standards Organisation that implemented a worldwide standardisation. However, the introduction of standardised container equipment can be traced all the way back to the 1780’s, with the first aluminium containers being produced in 1926. (Sawyers, 2008)
ISO Shipping containers are made of corrosion resistant steel, known as ‘Cor-ten’ steel. The material is a ‘weathering steel’ designed to be durable in exposed circumstances. (RSCP, 2013)
The ISO shipping container’s shell is made up of two elements; a steel framework consisting of four corner posts, two top and two bottom side rails, and two bottom cross rails, a top cross rail and a door header (for the entrance); and a corrugated steel envelope.
It is the steel framework which gives the containers its characteristic strength and stability; coupled with corner castings, allowing for a simple but very effective connection, the framework is capable of withstanding the forces imposed by nine ISO containers stacked on top of each other. (Container Handbook, 2015)
ISO shipping containers come in several standardised sizes. Typically, they are 8 feet wide, with the length varying i.e. 8, 10, 20, 30, 40 and 45 ft. Typical containers measure 8 1/2 ft in height, but a taller ‘high cube’ is available at 9 1/2 ft tall. (SJonesContainers, 2015)
What Containers are used for
Shipping containers were originally designed for the purpose of safely transporting goods. So effective was Malcolm McLean’s invention, that the shipping cost per ton to load dropped from $5.86 to 16 cents. His invention is considered so significant that the International Maritime Hall of Fame, named him ‘Man of the Century.’ (ISBU Association, 2010)
Adaptations for other uses
As time has gone by new uses have been found for shipping containers. Adapted shipping containers are now common-place on construction sites, providing various types of site accommodation e.g. site offices, toilets, showers, drying rooms, security and storage (Waco, 2015); allowing sites to hire the level of amenities to suit the size of project and enabling quick and trouble free site clearance.
When an ISO shipping container is used for the purpose of construction it is referred to as an ‘Intermodal Steel Building Unit’ (ISBU) and since 2006, have become increasingly popular, with adaptations reaching new levels of innovation (ISBU Association, 2010). Shipping containers have now been reprocessed into:
- Bistros Schools
- Urban Centres
- Hotels Workshops
- Nurseries/ Gardens
- Markets Studios
- Sports Halls
- Galleries Bars
- Swimming Pools
As well as being used for work and leisure, ISBUs are now finding popularity in the form of both temporary and permanent housing. Universities in Le Havre, France and Amsterdam, Netherlands have taken advantage of the shipping containers modular design by adopting them for new student housing. (Clark and Sattineni, 2013).
The Brighton Housing Trust in the UK have exploited the same characteristic for the purpose of temporary accommodation. Richardson’s Yard, consisting of 36 studio flats, was erected for the purpose of housing homeless individuals. (QED Property, 2012)
ISBUs as permanent accommodation are increasingly being reported in various forms of media. However, examples are still scarce and most are ‘statement homes’, such as those found on social media sites like Buzzfeed (2013) and the television programme, Grand Designs which featured an example in Ireland. (PB Architects, 2014).
The Advantages of Using ISBUs for Affordable Housing
ISBUs are modular in nature, making them ideal for temporary accommodation and are striking in appearance, well suited for high end statement homes.
However, ISBUs have a number of other characteristics which could be taken advantage of when producing affordable permanent housing for the ‘lower mainstream’ market.
ISBU containers are designed to be incredibly strong. ISO minimum standards state it must be possible to stack six fully loaded containers on top of each other. Modern containers are often built to exceed this standard, with as many as nine stacked containers common practice. (Container Handbook, 2015). This quality means several storeys can be accomplished, meeting the need to increase population density in the Capital.
ISBU containers can be prefabricated. ’My Container’ (2015) explains that up to 70% of the fabrication of a shipping container building can be carried out offsite which allows for construction times to be reduced by up to 40% (when compared to traditional methods).
My Container goes on to say that the level of onsite groundwork is also reduced; London Shipping Containers (2013) and similar sources agree, explaining that a shipping container only requires a solid pad foundation (typically no more than 300mm deep).
Container City 1 is an example of speedy onsite construction. The project took a total of fives months to complete, however, onsite installation took only four days. (Container City, 2013).
Brandt (2011) identifies one of the ISBUs key strengths as ‘modularity,’ allowing for the easy design of layouts, in particular with small rooms. The standardised sizes are also beneficial for costing materials. Allowing for more accurate estimations.
This modularity and potential for off-site production make ISBUs an ideal option to make the best use of small pockets of brownfield land.
Brandt also explains that shipping containers, due to their intended use are designed to resist harsh environments. Although they will succumb to weathering eventually, occasional maintenance and easily applied seals can overcome these effects. Additionally, according to S Jones Containers (2015), as ISBUs are made primarily from steel they are ‘very resistant’ to fire. As a method of construction, ISBUs offer a cost effective alternative to traditional ways of providing the structural strength of a building. Landmark Architecture (2014) explains that second hand containers are widely available at very reasonable prices as “the fees associated with returning the containers to their countries of origin is far less cost-effective than buying new containers” they go on to say that “with European residential property at a premium it’s no wonder that people are starting to look to these cheap sturdy stackable boxes for shelter.”
Disadvantages of Using ISBUs for Affordable Housing
There are also inherent obstacles to overcome if using shipping containers for construction. Brandt identifies thermal comfort and the need for skilled labour as issues to consider when using ISBUs (2011).
A shipping container is made out of steel so is an excellent thermal conductor. This poses a problem when trying to achieve the correct level of thermal comfort for inhabitants. The steel means that the ISBU’s internal space is too hot in warm climates and too cold in cold climates.
The requirement for skilled labour comes in part from the need to create windows and doorways.
However, Brandt goes on to state that “by insulating the container, and installing HVAC systems, the interior environment can become comfortable for any environment” and skilled labour can be reduced by prefabricating modules before shipping.
The internal width of ISBUs can also be an obstacle for design. Shipping containers are only eight feet wide, which means the use of a single ISBU requires a high degree of consideration in the planning of internal spaces. Placing ISBUs next to each other does alleviate the problem, but still requires designers to work in eight foot increments unless other methods are used to create the building shell.
This chapter set out to establish what information is available on the housing need in London that might be met by the provision of housing constructed from shipping containers. A further objective was to investigate whether containers have already been successfully used for similar alternative uses and whether there would be lessons to learn for the adaptation of containers for permanent living accommodation.
There is a significant amount of published information and statistics which demonstrate that there is a substantial shortfall of affordable and lower mainstream housing to meet the need for this type of accommodation.
The first part of the chapter has drawn on those publications to illustrate the issues of demand, supply and availability, income levels and mortgage availability which all combine to create the housing problem seen in the Capital.
The second part of the chapter established that there has been considerable alternative use of shipping containers in leisure and work environments and limited use for housing. In the main, housing projects making use of containers have tended to be for short term use, such as homeless or student accommodation.
In conclusion, contents of this chapter confirm that it is worth exploring further the potential for using shipping containers for permanent housing within the Capital to meet some of the demand for smaller homes.
Part 3: Research and Design Methodology
Scope of Chapter
This chapter explains the chosen research method used (questionnaires and interviews) to gain the information needed to address the aims of the dissertation. It explains the range of questions asked to obtain the data needed and a justification of the approach taken to the research.
The key characteristics of the respondents is provided, including profession, their type of project, sector and location; as well as a more detailed explanation of each respondent’s industry background and attitude towards the research.
This chapter will explain how the collated data was analysed.
Statement of Research Aim
The aim of the research is to understand the viability of using shipping containers for permanent accommodation to help meet the growing need for low cost housing (valued at less than £450 psf) in London.
Rationale of the Research Questionnaire
The Literature Review explored the current housing need within the Capital that might be met by the use of adapted shipping containers. It established that there is a considerable demand for low cost housing that is growing year on year.
As the practice of adapting shipping containers for the purpose of housing is still in its infancy, the number of informed and/or experienced sources that could share valid first hand experience is limited. Therefore, the decision was made that the primary research approach should be qualitative in nature; relying on the anecdotal evidence and first-hand experience of professionals and end users who have worked on or live in a project of this nature.
Naoum (2013, p.41) states “Qualitative research is ‘subjective’ in nature. It emphasises meanings, experience (often verbally described) description and so on. The information gathered in qualitative research can be classified under two categories ….. exploratory and attitudinal”. Naoum goes on to say “Exploratory research is used when you have a limited amount of knowledge about your topic”.
As this area of research is relatively unexplored, it was decided that a questionnaire with open ended questions would be the most effective method of gleaning important information. The literature review helped to identify key issues to be explored but open ended questions allowed respondents to provide insight that might not otherwise have been identified as areas of interest.
The primary research was designed to address the third, fourth and fifth objectives of this study. They are as follows:
- Identify the advantages and constraints associated with using shipping containers for providing permanent accommodation and in their construction. • Discuss the cost implications associated with adopting shipping containers for the purpose of housing. • Identify issues affecting end users, including thermal comfort, security and noise transference.
To ensure that all three objectives were addressed the research was split into three individual sections, each focussed on a different objective.
The questionnaire was planned in three sections to cover construction issues, costs and end user experience. The first section (see appendix 1) explored the general practicalities of incorporating shipping containers; issues with planning permission and the building regulations, the benefits and obstacles relating to the characteristics of shipping containers and the lessons that were learned by the respondents. This section of the questionnaire was distributed to clients, contractors and architects by email.
The second section (see appendix 2), was designed to cover issues of cost; how the cost compares to traditional construction methods, which elements are more or less expensive than traditional methods and whether the inclusion of shipping containers affects the costing process. This was distributed to quantity surveyors.
The third section was to be designed for end users, to cover general issues of comfort e.g. such as thermal comfort, security and noise transmittance; overall user satisfaction and elements that users would want to see improved. This was intended to be sent out to end users, after receiving contact details and permission from the scheme managers. When scheme managers were asked for permission to distribute postal questionnaires to users, this was met with rejection; due to the level of media attention projects of this nature had generated scheme managers wanted to avoid upsetting users with excessive inquiries.
It was originally intended that data about the experience of end users would be gathered directly from existing shipping container developments, through postal questionnaires consisting of both open and closed questions; however it only proved possible to obtain user feedback through sources of secondary data, where the developer had undertaken their own research on end user satisfaction. This meant that the design of the questions asked could not be influenced.
Rather than immediately presenting potential professional respondents with the questionnaire, introductory emails were sent out first, with an explanation of the reason for undertaking the research. This was done as a professional courtesy and to gauge receptiveness.
Individuals who expressed a willingness to take part were then sent the relevant questionnaire. Those who indicated that they would respond but failed to were sent reminder emails, or contacted via telephone if numbers had been previously provided.
Wherever possible, face-to-face interviews were also arranged. It was decided that these interviews would be most rewarding if they were conducted in a semi-structured format. Noaum (2013, p.55) explains that semi-structured interviews “start by asking indirect questions in order to build up a rapport with the respondent and then explore the specific issues that the interviewer has in mind.” As there were limited sources of information available the aim was to avoid restricting the respondent to offering information only relating to predetermined questions and to elicit as much useful information as possible from the limited sources available. Interviews took place with Contractor A and Quantity Surveyor B.
The Research Sample
Examples of ‘affordable’ and/or ‘lower mainstream’ housing built out of shipping containers are rare in the UK. For this reason it became necessary to extend the potential pool of respondents to encompass projects within the UK using ISBUs, regardless of use, that incorporated shipping containers. As there are many similarities within the scope of works for building projects whatever the intended use of the completed building e.g. dealing with utilities, meeting building regulations, the planning process etc. broadening the potential sample in this way was justifiable and produced relevant and valid data.
In total 25 individuals involved in 11 projects were approached (see appendix 3). The pool of potential respondents consisted of contractors, quantity surveyors, architects and the project’s clients (see table 2). The projects that were identified varied in purpose, including both public and private housing of differing quality; hostel accommodation; temporary housing; permanent and pop up markets and multipurpose commercial properties that offer office space, restaurants and studios.
Of these 25, seven completed the questionnaires and two of those also agreed to be interviewed.
Method of Analysis
The interviews conducted were carried out in informal settings which were not conducive to audiotaping therefore notes were taken to capture key points made by the respondents for later analysis.
Because of the small number of people surveyed and interviewed and the number of questions asked it was not felt necessary to carry out detailed coding of the responses in order to analyse the results. Instead each response was considered separately and compared to other responses to consider whether there were any similarities in experience. The key comments from sections 1 and 2 of the questionnaire and interview responses were captured in tables 4 and 5 under relevant question headings so that they could be easily considered and compared.
Using end user survey results provided by some of the respondents, relevant data was extracted for presentation in bar charts. This visual representation of the results enables simple analysis of the responses received and the satisfaction rates for the matters being investigated.
Part 4: Findings and Analysis
Scope of Chapter
This chapter presents the findings of the primary research.
The key elements from each respondent’s answers to the questionnaires and interviews have been tabulated and are presented below.
The responses to each question have then been analysed, identifying consistencies and contrasts between them.
Section 1 – Construction Issues Planning Permission and the Building Regulations
This section of the questionnaire covered the experiences of professionals in obtaining planning permission, meeting the building regulations and issues of health and safety and fire safety.
Each of the clients and the Architect experienced straightforward planning processes, either receiving no objections directly linked to ISBUs or some concerns over minor aspects that could be overcome through design changes. e.g. “The only planning issue relating to the containers was agreeing the colours of them.” The Architect explained that “it was the Council who first suggested the use of shipping containers, so they were quite receptive to the idea of using them” and Client B commented that they secured planning permission with all party support.
Client B experienced objections from an academic who argued that people should have ‘proper homes.’ The only other objections to the schemes were generic in nature; issues about increased on-street parking and refuse bins, which were in no way linked to the inclusion of shipping containers.
However, Contractor B had a very different experience. Contractor B reported that they had to overcome the “perception of sub-standard accommodation and aesthetics.” The internal space provided to occupiers was a concern with the standard sizes of shipping containers not meeting the Local Authority’s (LA) ‘standards.’ This was overcome as Contractor B’s scheme was for temporary accommodation, which meant that the LA’s concerns over the long term were not a factor and provided some room for negotiation.
Meeting the Building Regulations proved to be a more difficult process. Of the respondents who offered an answer pertaining to the Building Regulations, all experienced obstacles in meeting the current Building Regulations.
Client B commented that “the homes did not fit [the Building Regulation] templates;” and the Architect explained that issues arose because shipping containers “are not a standard building component” which means that “they do not have any standard form of building performance certification e.g. BRE certification/ UKAS accreditation/ CE markings, etc.”
Contractor B and the Architect who worked on different projects both stated that they had to reach compromises. The Architect explained that the intended use of the project left room for negotiation, which meant that certain parts of the Building Regulations i.e. Part L, did not have to be complied with. Contractor B explicitly states that “We agreed a few waivers where we were unable to adapt due to restrictions of containers.”
Additionally, Contractor B had to quash concerns over the containers’ suitability for meeting the standards set by the Disability Discrimination Act 1995, with specific attention to access and fire safety restrictions.
The issue of fire safety highlighted a divide between stakeholders delivering the projects and those who are charged with approving them. None of the respondents took the opportunity to highlight specific Health and Safety concerns.
Of the five respondents asked about meeting fire safety standards, four provided answers, all of whom mentioned that they faced concerns over fire safety. However, each seemed comfortable that either it was not actually an issue or a solution had been found to address the concerns raised.
The Architect reiterated that the complications arose from shipping containers not being a certified building component; and that there was a fear that since containers are excellent thermal conductors, a fire in one container could cause an excessive level of heat to be radiated, potentially igniting fires in neighbouring containers.
However, the respondents themselves all showed confidence in ISBUs’ ability to provide a high level of fire resistance.
Client A simply explained that building regulations meant that they had to provide at least thirty minutes of fire protection and as such they included a suitable level of fire boarding.
The contractors went a step further, providing specific examples of shipping containers being an excellent method of containing the spread of fire and protecting structural integrity. Contractor B reflected upon a case in Amsterdam where a fire broke out in a student accommodation complex built out of shipping containers. The result was that the fire remained contained within the module. The affected container needed to be replaced but the complex was fully functioning a week later.
Contractor A revealed that their company routinely supplies shipping containers to fire training service facilities for the very purpose of setting controlled fires, demonstrating how suited shipping containers are to withstanding the effects of fire. This also supports the findings of the Literature Review that found that ISBUs were highly resistant to fire (S Jones Containers, 2015).
The findings from this section of the questionnaire show the varying attitudes towards the use of ISBUs and the adaptability of the Building Regulations.
Responses showed that Local Authorities are open-minded to the concept of ISBUs and the Architect’s experience suggests that LAs are promoting the use of them. However, wider areas of the community are showing resistance.
When reviewing objections Local Authorities “can only take into account material planning considerations” (LB of Richmond, 2015) therefore schemes using ISBUs are as likely to face difficulties in seeking planning permission as any other construction project. Every construction project is unique, some face strong opposition, whereas others do not.
Although LAs are happy to grant permission for these schemes, the findings also show a level of cautiousness being adopted by their Building Control Officers. This is likely to be due to inexperience and the lack of an industry recognised standard for the use of ISBUs.
The fact that after consultation compromises were found and the projects were allowed to go ahead clearly demonstrates that ISBUs can provide the required standard of safety; this must be the case as UK Building Regulations are designed first and foremost “…to ensure the health and safety of people in or about buildings.” (Waverley Borough Council, 2015) From the above it can be concluded that the current UK Building Regulations need to adapt to this method of construction. If containers become more commonly used some of these difficulties may be overcome in the long term.
The Practicality of Building with ISBUs
Respondents had mixed experiences when installing the project’s utilities. Contractor A states that there was no issue with making utility connections, whereas Contractor B suggests that gaining access through the units was troublesome.
Interestingly, the Architect, who worked on the same project as Contractor A did feel there were issues when incorporating the services. They found that including the services through the base of the containers was problematic and raised the risk of water ingress.
These conflicting responses could be explained for two reasons; firstly; Contractor A has over 50 years experience of working with containers, whereas this was the Architect’s first experience of working with this construction method. Secondly, it may well be that designing out the risk of water ingress was a troublesome process, but physically implementing the services may have been simple once the solution had been decided upon.
Therefore, the two professionals on the same job may well have had different experiences. Lack of experience may also be the reason for the difference between contractor reports, as it was also the first time Contractor B had built with shipping containers.
When asked about other obstacles arising from the use of shipping containers, Client A simply stated that there were none. This is in stark contrast to the Contractors and the Architect who commented on various complications, including: the whole site having to be raised once the shipping containers were in place to allow wheelchair access into the containers; building control issues; a high level of bespoke design as “standard proprietary building products are not designed to be fitted to containers;” and there was a concern over the invalidation of the container warranties after alteration work had taken place.
Although shipping container adaptions are not a new concept, the need to go to such an extreme as to raise the entire site, as well as the other obstacles identified above, continues to demonstrate that the industry is still inexperienced in using shipping containers as a means of construction.
The rarity of these projects is such that manufacturers are not yet incentivised to design components that fit containers or to solve issues as commonplace as adequate wheelchair access. As these solutions do not yet exist the need for bespoke components and the like will negatively impact the cost of ISBU builds.
The Construction Industry and supply chain are still to learn the lessons from the use of containers and design solutions are likely to be developed as more experience is gained.
Advantages, Disadvantages and Lessons Learned
All respondents stated cost and speed of delivery as key advantages of this method of construction. Other frequently used words included sustainability, efficiency and simplicity.
The Architect highlighted the shipping container’s “inherent structural strength”, which is synonymous with containers, removing the need (and associated cost) of having a secondary structure.
Client B mentions advantages previously identified in the Literature Review. Client B states that a standard 40 foot shipping container has more internal floorspace than an average studio apartment. It is not clear if Client B’s statement is based on fact or opinion, but a report for CABE by Scott Wilson (2010) found an average Gross Internal Area (GIA) for a studio apartment to be 31.94m2, which is only slightly larger than 40 foot containers’ GIA of 28.34m2.
The GLA has set space standards for the Capital, which means that a studio apartment designed for one person must have a minimum GIA of 37m2. This means it would not be possible to house individuals in single shipping containers in London. However, two containers, with a GIA of 56.67m2, would not only meet these standards, but also meet the requirements for a 1 bed room apartment for two individuals. (Gov.uk, 2014)
Two key disadvantages were raised by respondents; although Client B praised the internal area of shipping containers, both contractors identified the internal width as a disadvantage (8 foot). However, it is not clear whether the issue of width poses problems for the contractor in carrying out their role; or if it was perceived as a disadvantage for end users.
The second disadvantage, identified explicitly by the Architect and a recurring theme in these findings, is the industry’s lack of familiarity and knowledge of working with shipping containers. The Architect states that:
“This was the first container project in our office, the first for our client and for the contractor, so we had no precedent. It was like we were starting from scratch with regard to a lot of the detailed design work with very little literature or guidance, everything was bespoke.”
The Architect believes that the key lessons they learned when working with the shipping containers were related to the structural integrity of the containers and their tolerances. The Architect makes reference to the need for structural reinforcement when not stacking the containers in the manner in which they are designed (directly on top of one another, along the load bearing steels) and/or when a significant amount of side panelling is removed for adaptation purposes. Client A appears to agree, stating that the involvement of a structural engineer from an early stage was a significant help.
The advantages highlighted by the professionals reflect the perceived strengths of using shipping containers in construction projects that were identified from the Literature Review. The key advantages were cost and speed of delivery; these are both crucial factors in the viability of construction projects in general and this is why the use of ISBUs in the provision of low cost homes is worth exploring further. Many of the disadvantages identified are likely to become less of an issue as experience of ISBUs builds within the industry and greater knowledge is developed and shared.
Section 2 – Costs and the Costing Process Costs
Quantity Surveyor A (QS A) found construction with ISBUs to be cheaper; whilst Quantity Surveyor B (QS B) states that it was not. However it is important to note that QS B’s project was based in Romania where, as they commented, all methods of construction are cheaper than in the UK. For this project the construction phase was carried out in the UK.
QS B goes on to explain that a traditional build in Romania would have cost approximately £4,000, whilst the adapted shipping containers cost approximately £12,000.
Cost is one of the key factors that shapes a project and the Literature Review highlights it as one of the key advantages of shipping container construction. However, the response from QS B shows that the potential benefits of shipping containers may not always be present; the local economy has a strong influence on the housing market.
Although QS B stated that the cost of the build was considerably more expensive than the local economy in Romania, the construction method may still be cheaper than traditional methods in London. The cost per square metre was £857 and QS B estimates that a similar build using traditional methods in the UK would have cost approximately £1,200 per sqm; a saving of 25%.
More impressive still, QS B includes the cost of transport for each container (£1,500) within the £12,000 total, showing that there may be more savings to be achieved.
QS A’s project cost a total of £900,000 and worked out at £900 per sqm. QS A states that if they had used traditional methods they would have expected the cost to be £1500+ per sqm.
As well as the shipping containers themselves, the savings achieved are also the result of the costs of other elements of a build being directly affected by their inclusion.
The advantages provided by the steel framework of shipping containers is evidenced by QS B, who states that the use of ISBUs meant that strip foundations were not necessary. Instead, 300mm x 300mm pad foundations were sufficient. The steel framework also acts as its own superstructure, removing the cost of additional support.
QS A found other cost savings linked to construction. These included a reduction in site waste and the transport of materials to site.
Specific to their project, QS A mentioned that elements of the external stairs and walkway could be tied to the existing structure, further reducing superstructure costs; and that demolition costs would be less compared to a traditional build. This is supposed due to the modular nature of the build which would allow the scheme to be systematically deconstructed; and if required, presumably the structure could be erected elsewhere. QS A also suggests the consideration of embodied energy.
Potential savings were also identified outside of the construction phase. QS A remarked that the cost of funding the project was cheaper overall, this reduced the level of interest that needed to be paid on funding and opportunity cost on the cash used to fund the development.
Although specifically questioned on the topic of cost, both parties state speed of delivery as a major advantage. QS A states that it is “significantly quicker” – their project took 14 weeks to construct versus 12-18 months if traditional methods had been used. QS B explains that a converted shipping container takes six days to build and one day to set up – traditional methods in Romania would have taken four months.
QS A clarifies the relevance of this, explaining that the reduced time it took to deliver the project means that returns on investment are “coming back much quicker than with traditional [methods,] creating savings.”
When asked about elements that were more expensive due to the inclusion of ISBUs, QS B identifies the forming of openings for walls and doorways as an additional cost and states that 500mm thick insulation and formica faced plywood were used to enhance durability.
QS A simply states “I don’t think so” but does draw attention to the planning and design fees being higher than anticipated for a temporary structure.
Of the seven respondents who took part in this study, two were in a position to provide detailed information about the financial element of their projects. However, all of the respondents indicated that the use of ISBUs resulted in lower costs.
Although trends could not be determined, the two quantity surveyors provided compelling evidence that suggest significant savings could be achieved. The figures provided imply approximate savings of between 25% and 40%.
Considering the cost of land in the Capital, the indicated speed of return on investment is also a compelling argument for the adoption of ISBUs.
When considering the idea of utilising ISBUs from a completely financial point-of-view there is evidence that shows that adapted shipping containers are a viable means of construction in the Capital.
The Costing Process
The Quantity Surveyors had conflicting views. QS A found the costing process to be both more accurate and efficient, this was due to the “kit parts manufactured offsite”, which allowed for more predictable timeframes and costs. QS A also found that the speed of construction had a positive effect on the costing process; as there was a shorter programme the availability of labour and materials was more predictable and less prone to “fluctuations.”
In contrast, QS B found that “the final costs were higher than anticipated” but explains that as it was a pilot scheme they had no previous experience or knowledge of potential costs.
QS B identifies two key factors that resulted in the higher cost. As the ISBUs were second hand, work had to be carried out to remove dents from the containers and forming openings in the containers was an expensive procedure.
The small sample size and the conflicting views prevent a convincing conclusion from being formulated around the costing process. QS B’s experience is unfortunate, but is explained by the project being a pilot scheme; QS B had no prior experience or knowledge of ISBUs.
It may be reasonable to assume that QS B’s experience of the costing process would improve as the process is repeated and begins to resemble the experience of QS A, who reported a more predictable and reliable process.
Although not conclusive, it is expected that the standardised modular nature of ISBUs would have, if a larger sample size had been obtained, seen more responses in line with QS A’s.
Section 3 – User Feedback
As explained in the “Research and Design Methodology” responses to this section of the questionnaire was largely limited as a result of not being able to approach users directly. Instead, these findings are based on the limited insight provided by respondents through pre-existing surveys obtained from scheme managers.
All five respondents reported overall positive feedback from the end users. Noise transmittance was not an issue, and in the case of Contractor B, the containers were found to be “right on the building regs’.’ Security was also reported as good by two respondents on projects where security was an important factor to the project’s success.
Surprisingly, internal space has not been a major complaint from end users. Contractor A is the only respondent to explicitly mention that an individual was concerned about the internal space. As the scheme has 29 end users, the fact that only one has raised it as an issue would seem acceptable.
This finding is further backed up in a report produced by Client B, that specifically focussed on the user experience of the tenants residing at their residential shipping container scheme.
Figure. 6 shows that only 7% of the tenants who responded to the questionnaire showed any level of dissatisfaction about the size of the containers. This is interesting as the results contradict the concerns of the contractors, who identified the internal width as a key disadvantage of ISBUs but it does not seem to have impacted on user satisfaction.
However, thermal comfort was a recurring complaint, linked to both inadequate insulation and extremes of weather. Contractor B refers to issues of “heat retention.” Again Client B’s report confirms this with 63% of residents complaining of unsatisfactory insulation (see fig. 7); and in one project the solution to weather extremes was to erect a separately manufactured metal roof to shield the units from the sun and protect them from harsh weather.
Inadequate insulation has led to occupants reporting the receipt of high electricity bills in attempting to keep warm; 69% said that the cost of heating and electricity was expensive after moving in (see fig.8).
The issue of thermal comfort has been linked to a high level of individuals who do not find that the accommodation provided is good value for money. When surveyed, 56% of occupiers felt the homes were “quite expensive.” (see fig. 9)
There were some interesting observations made by the respondents but in the main the remarks were in line with expectations arising out of the Literature Review, such as thermal comfort issues.
Client B’s housing scheme was built to house low income individuals and couples, some of which had a history of homelessness. These individuals represent a very real demographic of the London population for which the shortage of affordable and lower mainstream homes, referred to in the Literature Review, is an issue. For low income households, which fall within the 70% of London households earning less than £50,000 per annum, the price of electricity and heating is a large concern.
This findings show that thermal bridging is a very real issue that requires an adequate level of consideration in the design phase. Ensuring sufficient levels of insulation would ultimately reduce the running costs of the household making this type of home a far more realistic option for average households.
Client A summed up that user expectation is a significant factor in satisfaction levels; explaining that in future projects there is a need to manage end user expectations so that they are more realistic, whilst more effectively communicating the end user requirements.
Client B’s report showed that upon first hearing about the residential project, 87.5% of individuals “thought they sounded interesting” with 43.75% of participants stating that they “really wanted to move into one.” The high level of interest in the idea of living in a shipping container is in line with the findings of the Literature Review.
Part 5: Conclusions and Recommendations
Scope of Chapter
This chapter will discuss the conclusions that can be drawn from both the Literature Review and the findings of the primary research in relation to each of the objectives. The limitations of the research will be identified and discussed and any recommendations for further actions and future research will be made.
Conclusions in relation to each objective Objective 1. Understand the current housing need within the Capital (London) that might be met by the use of converted shipping containers
The Literature Review identifies an annual deficit of approximately 15,000 “affordable” or “lower mainstream” homes in London. Additionally, the Literature Review clearly identifies a number of factors that contribute to the level of housing need in London, including; large disparities between house prices and annual earnings; excessive mortgage deposits; decreased levels of lending from banks; and a reduction in new build house sizes.
This high level of demand and the potential of shipping containers to help meet this is echoed in the primary research, when Client B explains that they could have “let [the affordable housing] three times over…and re-lets have not been a problem.” This illustrates the high demand for affordable housing and that there is a section of the housing market that could be met by their use.
The space standards required in London means that more than one container would be needed to create the space to house an individual; by using two containers, a one bedroom apartment for two individuals could be created.
Objective 2. Research how shipping containers have been adapted and used for other purposes
The Literature Review explains the origins of the shipping container and the purpose of its design and establishes how effective it was for the transportation of goods. It also explains how the design of the shipping container has been improved over time and the various ways it has been repurposed. Finally, there is a detailed examination of the various strengths and weaknesses characteristic of shipping containers.
The Literature Review shows that whilst the concept of adapting shipping containers for other uses is not new, the practice of using shipping containers for any type of housing is still in its infancy. The use of them for permanent housing is even less developed. However, the few examples uncovered demonstrate that container homes can be successful.
The primary research that was conducted confirms the variety of uses of adapted shipping containers, such as for open air market stalls and affordable housing. Not only have these projects been delivered, but the user feedback indicates that overall users were broadly satisfied with adapted shipping containers; both as a concept and after using them for their adapted purpose.
Objective 3. Identify the advantages and constraints associated with using shipping containers for providing permanent accommodation and in their construction
This objective has received the most clarification. The Literature Review and primary research identified similar issues with regard to the advantages and constraints of working with shipping containers. More detailed and practical information was elicited from the primary research; hearing from those who had direct and recent experience of using containers was valuable in helping to draw conclusions about the viability of using containers for the construction of permanent housing.
Obstacles in relation to meeting the UK’s Building Regulations have been identified as well as the potential for objections during the application for planning permission. The research showed that the current building regulations are not yet drafted to easily allow for ISBUs, but after consultations and reassurances, ISBUs are accepted as suitable for construction, with permission eventually granted.
The concerns around granting planning permission were centred around the perception of shipping containers, both in their ability to provide adequate living standards and to be finished to a high aesthetic finish. End user feedback though, was positive overall, and Client B’s own study showed that before their own project was built, there were individuals who had positive opinions of the use of shipping containers.
Advantages beyond cost, discussed above, were identified and included factors such as sustainability, speed and efficiency of installation, availability, durability and strength, and quick return on investment.
Disadvantages were not universally identified, the internal width of the containers came under scrutiny, with contractors identifying it at as a problem; although end users, in the main, contradicted this view.
The London space standards mean that more than one container would have to be used. If the two containers were stacked one on top of the other the narrow footprint of a single container would be retained and as the London space standard for a one bedroom two storey building is 58m2.
Only the addition of a small extension would be needed to benefit from this.
The evidence shows that, just as with any other construction method, there are practical obstacles that occur that must be resolved; for example, one of the major concerns illustrated was the need for better insulation. However, these obstacles can be overcome, in this case, through thicker internal insulation or the inclusion of external insulation.
On the whole, it is clear to see that the problems with planning permission and meeting the building regulations are born from the fact that ISBUs are a comparatively new method of construction which the UK construction industry has not yet fully embraced. In the same way, negative perceptions and low expectations of ISBUs are the result of a lack of familiarity.
Furthermore, the fact that ISBUs were not a ‘typical’ building component meant that a high level of bespoke work was required.
Practical construction issues, such as heat retention and the containers inability to adapt fully to the building regulations, are problems that will be overcome as more research and future innovations are made into best practices. If the industry adopts ISBUs as a realistic construction method, then it is likely that the market will adapt, producing standard components and investing in the development of suitable products. The hope for the future would be that many of the obstacles would become irrelevant, allowing the inherent benefits of the shipping container to set the method apart from traditional choices.
As for the suitability of ISBUs for the provision of permanent accommodation, one respondent stated, “Shipping container homes provide a temporary contribution to the [housing supply and demand] challenges being faced.” Whilst another believes “…that they could make brilliant low cost housing at a significant saving, we would just need to convince lenders so that they could be mortgaged, I am sure buyers would react well if priced well.”
It is the opinion of respondents that ISBUs make suitable homes, but as many of the constraints were resolved due to the temporary nature of the successful projects, on the whole the responses received and examples found did not support container use for the provision of permanent homes.
Objective 4. Discuss the cost implications associated with adopting shipping containers for the purpose of housing
Overall, the research supports the idea that building with shipping containers was a cheaper method of construction, when compared to more traditional methods in the UK.
The secondary research initially identified cost as one of the possible advantages of shipping container use, with examples of reduced construction time, less costly foundations and less on site labour required. Cost was then unanimously identified by primary research respondents as one of the key benefits of ISBU construction. Where costs per square metre were provided they were significantly lower than comparative estimated costs for more traditional methods of construction, with savings at least in the region of 25%.
One respondent’s answers to cost questions highlighted that, from a purely economical point of view, shipping containers only offer a solution in particular housing markets. Whilst ISBUs would offer a cheaper alternative in London and in other areas of the UK, the economic situation and availability of materials and labour in other countries such as Romania, would not lead to the same price comparison. Although it is worth remembering that cost is not the only factor that affects project choices. In that particular case study, the construction phase was shown to be reduced from four months to six days as a result of opting for ISBUs.
As well as the implications for a project’s total cost, it was also an aim of this project to understand how the process of costing may be affected with the use of these modular components. QS A commented that “due to kit of parts manufactured off site, this gives certainty on time and cost. Labour and material costs are less subject to fluctuations often experienced on a long term build.”
Cost estimates will become more accurate and quicker to carry out due to the modular nature of shipping containers. Once the construction method has been utilised more often and the process of costing an adapted container has been repeated, then a number of standard measurements will be known e.g. areas for insulation, drylining, internal floor and ceiling areas and finished floor to ceiling heights etc. Additionally, supply frameworks will be developed that will allow for a simplified process of obtaining up-to-date rates.
Objective 5. Identify issues affecting end users, including thermal comfort, security and noise transference
The primary research left it open for respondents to identify any relevant issues that had been raised by the end users of their projects. Despite the open nature of the question, few issues were raised.
This speaks to the overall suitability of shipping containers for homes, the only issues that were expressed were weaknesses that had been identified as potential problems in the earlier Literature Review, for which there are already recognised solutions. These included the presence of condensation, prevented through adequate ventilation and the use of foam insulation; and heat retention, overcome by insulating successfully.
Addressing this will also overcome the issue raised by occupants of the high cost of electricity.
Conclusions from Key Questions
The investigation carried out for this dissertation to address the key questions set out on page 5, has shown that there is an unmet demand for low cost housing within the Capital. There is evidence that shipping containers have been successfully adapted for other purposes and there is potential for this to be built upon and refined to incorporate shipping containers to help resolve some of the housing issues in London.
The advantages and barriers faced when using shipping containers for uses other than their original purpose have been shown to be surmountable in the small number of schemes that have been built in the UK.
The main barrier specific to converting shipping containers for the provision of residential accommodation from this research seems to be that they have in the main been seen as short term solutions with a limited life. Very few examples were found of developments that were considered to be permanent.
There appear to be huge potential cost advantages, not just in terms of build costs but also time saved, quicker returns on investment, lower interest charges on loans to fund the schemes and opportunity cost on that cash, residual values on deconstruction, embodied energy, waste removal from site and transporting of materials to site.
The albeit limited available feedback from users supports the potential for more developments for residential use. Both developers and planners need to embrace the potential for making this concept a long term solution.
Achievement of Research Aim
The aim of this dissertation was to understand the viability of using shipping containers for permanent accommodation to help meet the growing need for low cost housing (valued at less than £450 psf) in London.
The information obtained from this study supports the premise that the characteristics of shipping containers makes them suitable for the provision of low cost housing to help meet the demonstrable need for homes affordable to the majority of those on incomes below £50,000 living in the Capital. However, it has not been possible from the information gathered to assess their suitability for use in the provision of permanent housing.
The reason they are thought to be viable is because they have been found to be: lower cost, structurally sound, suitable for small sites, low maintenance and capable of meeting Building Regulations. Other advantages identified were the speed of construction, quicker return on investment and reduced waste.
Positive user feed back had been received on the whole; a majority of the users were satisfied with the finished ISBUs and the homes could have been let many times over.
However, this viability had in the main been achieved for temporary structures due to building regulation and planning issues and may not be replicated in London if they were permanent. The space standards in London were also identified as a potential barrier.
More developers and individuals should be encouraged to consider the use of ISBUs for the construction of low cost homes on brownfield sites in London; this would help to make best use of smaller pockets of available land and help to limit the need for expansion into the green belt.
Local authorities need to be educated on the possibilities that ISBUs present in addressing their local housing need and need to consider how their planning approval processes might support their innovative use.
Building regulations need to be adapted to account for the potential provided by ISBUs so that individually agreed waivers are not required and developers have a clear understanding and consistency around the requirements that need to be met. Limitations of the research
The limitations of the research revolved around scarcity of case studies to draw upon; low response rates to questionnaires, mainly due to the excessive work commitments of potential respondents; barriers to accessing end users; and limited sharing of cost information. In addition, with hindsight, the questions asked, whilst deliberately asked in a way to elicit as much information as a respondent was prepared to provide, could have been supplemented by more detailed closed questioning to obtain more consistent responses to aid comparison.
Due to the use of ISBUs being comparably untested as a method of construction in the UK, the number of existing residential schemes that incorporated them was extremely limited. This lack of examples was the reason that the research was broadened to projects constructed for other purposes e.g. commercial and office space. Even with this measure, the number of projects to draw from was still small.
Having selected 13 appropriate projects to study it proved difficult to make contact with relevant parties in order to distribute questionnaires and arrange interviews. Many, both participants and those who turned down the opportunity to participate, made mention of their heavy workloads. This is one of the main reasons for the low response rate and lack of opportunity for face-to-face interviews and the inability to go back and ask follow up questions for clarification.
If all those approached had responded, providing qualitative answers to the questionnaire, then a great deal of useful information might have been gleaned allowing conclusions to be drawn with more certainty. Those who responded provided quite detailed information, but the low response rate meant that trends could not be identified.
A particular frustration was the inability to make direct approaches to users of the projects to find out first hand about their experiences of using the buildings. This was because of the amount of interest shown in these types of buildings, which are seen as novelties, and the reluctance to expose the occupants to more questioning and publicity. The study instead had to rely upon research that had been carried out by the developers, so was restricted to the questions they had already asked which did not exactly match those that were needed for this study.
Professionals were happy to comment on cost implications in general terms but actual project cost information was very limited. This was perhaps understandable and partially expected, but did hinder research with regards to Objective 4: “Discuss the cost implications associated with adopting shipping containers for the purpose of housing.” However, all respondents confirmed lower costs were an advantage.
This study sought to generate an overview of shipping containers when used as a building component, viewing ISBUs from various stakeholder perspectives.
As ISBUs are not yet a mainstream construction method potential fields of study could include looking at the factors that prevent people from opting for an ISBU structure; or interviewing manufacturers to understand what they would need to see in the industry to start producing components that are compatible with ISBUs.
Future research could be undertaken to focus in on some of the individual objectives set out in this dissertation, e.g. carrying out detailed studies of the financial implications of ISBUs, or end user experiences once sufficient time has passed for occupiers not to be suffering from the excessive attention generated.
It is unlikely that the use of ISBUs is going to grow to such an extent in the foreseeable future that further research can take a more quantitative approach. The potential sample sizes and type of research that can be conducted with a degree of validity will remain limited and therefore key research may be best focussed around barriers to entry.
For example, this dissertation found that stakeholders experienced issues in meeting the Building Regulations. This could offer a field of further study, to better understand how ISBUs are perceived by building control officers and planners and how obstacles could be overcome.
Editors notes: Some content has been omitted from the original dissertation for reasons such as privacy or image copyright.
Container home images courtesy of Atelier Riri and features a container home built by their team of architects in Indonesia.
The views within this text are those of the writer Owen Connolly and should not constitute as advice from Adaptainer. As such we do not accept any liability for the accuracy of the information and recommend you seek independent advice on building shipping container homes in the UK .