External shot of the U-Build Box House in Graven Hill Bicester

Box House, Lenny Codd

A New Way to Build a House

We talk to Kyounghwa Jung, Editor at GARM magazine in Korea about our fabricated system. Ben expands on the rarity of this type of architectural service and the future of our self-build projects.

U-Build is a modular wooden construction system that assembles block modules to build frames. It’s innovating the way we think about architecture by making it easy for anyone to plan and build a house without any special tools. When and how did you start this project? What purpose did you plan to use it at that time? Tell me the philosophy in U-Build. 

U-Build was developed by Studio Bark with structural engineering from Structure Workshop and was first produced in East London. We aim to transform the way people think about buildings and the way they are built, by simplifying the construction process and enabling anyone to participate. The term affordable housing is often used to describe a particular type of dwelling, providing shelter at a price that can be realistically achieved. This is something we are genuinely interested in doing, we are not looking to make huge profits from the system in a financial sense, however, we would like to think that humanity and the community could profit from this for our future.

The whole point is to empower people to do their own thing, it is a personal experience we want people to have.

Please introduce the characteristics of U-Build that distinguish it from the existing architecture. How much time and money do you save compared to the existing method? Also, what are the advantages of a U-build system compared to other projects based on prefabrication modules, such as Wikihouse?

Our system is simple, however, people will need to be committed to a project. Finding the time to do construction is often tricky, especially if you need to work full-time in order to pay for the build. This could slow the process down if only evenings and weekends are available. Obviously, it depends on the demographic. If you are a young family, with small children then self-build can be more stressful for the parents as they have to juggle home life, possibly in temporary accommodation, and the build. However the beauty of the system is that it’s quick to assemble, so once all the parts are on site, then a building can potentially be watertight within a matter of weeks, making it possible to move things into. We find that short bursts of activity – perhaps with the help of friends – can work well in parceling up the project into achievable chunks. These can be aligned with key stages within the build, like ‘getting the base down’, ‘getting watertight’ etc.

The point of the U-Build system is to empower people. Designed and engineered by people for people. Once the core ingredients have been produced with specialist machinery, then the actual fabrication is down to you on a human scale, a low impact architectural level that does not involve heavy machinery, complex tools, and skills which take years to learn. Once the basics are built, then some specialist trades may be required to carry out certain tasks: electrical wiring, plumbing etc. For safety reasons, this is also important. However, 80% of the work can be accomplished without any special trades. This means you can save a significant amount of money due to no unnecessary labour costs. Some people do still employ a builder/contractor/project manager to help, but we offer thorough instructions and guidance when required.

This allows projects to be set within the community and carried out as part of a network of folks, willing to engage on a scale manageable for many and hopefully available to all.

Essentially, with the correct local resources, creating good quality shelter in this way should be accessible to everyone, all over the world . From individual builds to larger community housing projects.

The flatpack kit(box) consists of five wooden parts. Please introduce the basic specifications(size) and components of the flatpack. How did you decide the specifications of the flatpack kit?

The system is based on standardised sheet material, mainly 18mm spruce plywood. This in 2440x1220mm form is commonly cut on CNC machines of the same bed/cutting area size. Developing a product on a global scale requires a universal language, this format offers just that. It means that if there is an issue, we have a catalogue of standard procedures, processes, and parts we can implement efficiently. More proactive than reactive.

What is the load and structural strength supported by one flatpack kit(box)? How strong and durable is the U-Build frame compared to the reinforced concrete structure?

The strength of the material in certain configurations can dictate the size and layout of a space, but for the most part, with the modularity, there is a large range of options available to create a desired space. Often this is client led as we are helping them solve problems and make decisions with ease. The simplicity of the bolt together box system means that if something doesn’t work, in the real world after a few months or years, then within reason, they could just dismantle a wall and put it somewhere else if they want. 

Because the system is designed around optimising sheet material, in order to limit waste, in order to provide a construction method on a human scale, then the scope is fairly wide, without heavy machinery. Though when starting to work at height and with expansive floors/ceilings support needs to be considered. As each design can be tailored to the customers needs then there are endless ways to configure the boxes, windows, doors etc. We can offer generous size living spaces without compromising the structural integrity by using our software to generate renders quickly, giving the client an experience they can understand and appreciate. We work closely with a structural engineering team when doing R&D and to figure out the limitations carefully, especially if something is of a scale we haven’t worked on before. 

Concrete itself isn’t a strong material, it is the reinforcements that make it possible to create huge spans, otherwise you would essentially be putting yourself under a giant biscuit that could crumble at any point. Obviously the more framework the tougher it would be, but there is a big environmental footprint in doing this. Our system offers a much lighter option, on a manageable human scale, the big energy, time, machinery and skill needed to pour concrete, regardless of its toxic impact in this case, makes the reality incomparable.

Box House, Lenny Codd

Box House, Lenny Codd

What is the minimum and maximum size & height of a building that can be built by combining boxes?

The system is designed to be able to go up to three storeys, and we’ve already made two storey homes with flat roofs. Our standard single-story pod buildings are normally no taller than 3m. You could create a dog kennel at around 900mm if you wanted a very small scale version. This is the beauty of the system being modular. There is no reason we could go taller, however it hasn’t been tested. Obviously the higher you go the more risk there is involved, which would require extra precaution, safety features to be added through the build, like scaffolding, harnesses etc. Generally, the demand has been for single storey structures, perhaps as this scale feels more achievable to more people.

Please introduce about the process of purchasing products, building spaces using U-Build system, and discarding them after use.

Depending on where you are in the world, we want to be able to offer the system as local as possible. This means sourcing a CNC workshop, materials and all the general components/hardware that make up a U-Build. Our entire system is based on the idea of ‘leaving no trace’ therefore the intention is to have a building that is as permanent as you need it to be, but always have the mechanisms of a temporary structure built in so you can remove it, without leaving any trace of its existence there, if you need to. However, this doesn’t mean it goes into landfill. Our original concept pod for the system has been built and dismantled ten times on different sites around the UK, so we know the system is reusable, which is great. The longevity comes from the modular form which can be dismantled and reused and even reappropriated many times over.

In addition to the frame, the architecture requires a number of elements, including insulation, waterproofing, finishing materials, windows, facilities, and hardware. Can the U-Build frame serve as a finishing material? Using the U-Build system, which stage (e.g., foundation, frame, window, insulation, waterproof, equipment, furniture) in the whole construction process can be finished, and what areas should consumers prepare for themselves?

The internal walls are generally the finished article, if people want to clad them in something else then they are welcome. The whole point is to empower people to do their own thing, it is a personal experience we want people to have. We recommend that the walls are protected with plant-based oil, to help them last. For the most part, we are always looking at new technologies and materials to make the U-Build system more efficient. We try to work with suppliers that align with our values and recommend these to our clients who want to source many of the components themselves. As we offer the system rather than a full service build we don’t engage with some trades, services and components directly, however we also encourage our clients to look at alternative suppliers to the mainstream mass produced options and go through local channels where possible. As our files are digital, the model transcends location until shelter is physically needed, from that point minimal action can be taken to disrupt the local environment and resources.

The U-Build system consists of garden studios and homes that build spaces, and an Fit-outs that is an interior element. Please introduce the features, installation method, and use for each type. Which of the 11 types of Garden Studio and 4 types of Homes are the most popular?

With the current climate, many people are working from home and looking to create space in their gardens. The most enquired pod is the barn owl. However, the range of use is vast, from extra workspace to music studios, yoga studios and guest bedrooms. We are also able to offer interior workspace meeting pods and acoustic wall systems that help make open plan office space more diverse.

If we purchase a U-Build system, what kind of services do you provide? (Bespoke furniture, Planning drawings, On-site building assistance, Pre-made boxes, Pre-fabricated structure, construction classes, etc.)

All the above, within reason. We are able to do site visits within the UK however on a global scale we can offer our instruction details and technical experience via online video conferencing and consultations. Essentially, with the correct local resources, creating shelter in this way should be accessible to everyone, all over the world. Growing individual projects to community housing builds.

Buildings must meet the basic performance required by building laws such as fire resistance and insulation. In the UK, is it possible to build U-Build and live in right away without going through construction permits or legal performance verification? If not, what additional process should we go through? What process can we go through to make a U-build house in Korea? 

We have many international enquiries and always encourage people to check with their local authorities. Even within the UK, local authorities and councils can vary on what is permitted. Some people have land in conservation areas that require special permits, size limitations and local material considerations that need to be adhered to. Any building that is to be slept in needs planning permission here, but most pods fall within permitted development if you are using them for anything else. We offer basic drawings for planners, if you require them, to help your case.


Why did you choose wood as the material for U-build? Please introduce the pros and cons of using wood. What other materials did you consider besides wood?

The core of the U-Build system is a CNC cut plywood frame. The plywood used in the construction has zero added formaldehyde and comes from FSC certified, well-managed forests. We never use tropical hardwoods or materials where we cannot be sure of the origin.

We believe in a circular economy approach to construction, where all pieces of the building can be taken apart after use and used again. This means that the same building can have many lives and that you don’t need to take out a sledgehammer every time you want to change something in your building (even if that is fun).

We use locally sourced low-impact materials wherever possible to reduce our carbon impact. If you would like us to carry out an embodied carbon impact assessment of your project this can be arranged.

We are always searching for new materials and suppliers to improve our carbon footprint, and so if you find a new product that you would like us to test and incorporate as part of your build please let us know.

This is an interior staircase photograph of Box House. It is made of U-Build in collaboration with Studio Bark and has been featured on the Grand Designs TV show.

U-Build uses Ecobearer made of recycled plastic for support, and uses natural wool and neck fiber as insulation. These are enhancing the eco-friendly aspects of U-build. What criteria did you choose for these materials or products?

As mentioned above, we are always searching for new materials and suppliers to improve our carbon footprint, these are the companies we have found that align with our values that are also off the shelf, so can be ordered, delivered, and usually readily available within a few working days.

U-Buildings have a wall U-Value of 0.3W/㎡k as standard and achieved air-tightness levels of 2㎥·hr/㎡ @50Pa. How did you achieve this high level of performance?

Developing a system on a small scale over many years means that you can see the results, develop, improve and move efficiently as the feedback is immediate. The materials we landed on are from suppliers that produce quality products we can rely on and recommend to others. Again, there is no reason why these numbers can’t be improved further, as technology becomes even better and genuine environmental concerns are tackled.


Until now, How many architectures are built with U-Build system and what are they being used for? If there is a project that got great results by using U-Build for new purposes instead of the existing method, please introduce it.

The system is readily available and can be produced globally, where there is demand and resources. There are a variety of community projects, commercial fit-outs to family homes and garden pods we’ve had the privilege to be a part of. The interest has certainly grown as our exposure has increased.

Designed and engineered by people for people. Once the core ingredients have been produced with specialist machinery, then the actual fabrication is down to you on a human scale.

Please select representative U-building project and introduce the background, design, planning and construction process, and results.

For those new to the system, here’s a brief summary on our most well known project, Box House:

On 25th April 2019, the U-Build system was featured on the new TV series of Grand Designs: The Street on Channel 4.

The Box House project built by using the U-Build system is one of 10 pilot houses chosen for the new Grand Designs series. It was built on the first street in Graven Hill, Bicester which is a pioneering Development of 1900 Custom and Self Build houses. The Graven Hill project is of national significance, a ‘vanguard’ project aiming to help the government double CSH Homes by 2020.

The program centered around a young client with a difficult brief: namely to provide a robust, affordable self-build solution that allows for their limited construction experience. As a result, the system was conceived as a direct solution to the client’s problem. It was developed by Studio Bark with help from Structure Workshop and Cut and Construct. 

It enabled the client to create the home of their dreams, the Box House, which is a large 2 bedroom house with the adaptability to change to a three bedroom in the future. The internal layout was designed to be light, bright and open, while the exterior was set out with carefully detailed black timber cladding.

Sustainable, made of natural materials, easy to build, modular, flexible and cost-effective, our ultimate goal for the U-Build system is making it available for the masses to create affordable houses, workplaces and eventually communities anywhere around the world. This was a perfect opportunity to demonstrate how the U-Build system functions to the public.

In conclusion, the project showed how future housing could be delivered via a wide distributed network of end-users who are empowered through a series of safe, affordable, effective and assisted self-build solutions such as U-Build.

The episode is available to watch on Channel 4 on demand.

If you have a new type or project you are preparing, please introduce it. What kind of space do you want U-Build to be in the future?

Along with Studio Bark, we are working in the community to bring awareness to the idea of disrupting traditional and often redundant building and construction practices, for example through the ‘No Building as Usual’ project. Technology is crucial in gathering data to provide us with a reference point on the principles we promote, and we hope to build in more information to our models in the near future, such as embodied carbon calculations. The high energy use nature and need for resources in the industry is enough to concern most people. Whether they act upon it is another thing. Being active is essential to evolving ideas progressively. We are constantly looking to improve our own working methods and practices, this in turn, spills out into the community at large. We support social enterprise and charitable projects that align with our ethos and are always seeking to collaborate with those who are looking to make positive change. If we don’t engage then more trouble may be on the horizon, it is a chance to change things for the better that we are fully embracing.

Find out more about the U-Build Box House.