Box House

• Architetti

Studio Bark reveal their first ‘U-Build home’ - a two storey house built by the client and a team of students from a CNC-cut kit of parts.

Box House is one of 10 pioneering self-built houses, built at Graven Hill in Bicester: a development which will eventually comprise 1900 Custom and Self Build (CSB) homes. The Graven Hill development is of national significance, a ‘vanguard’ project helping to meet the government’s commitment to doubling the number of CSB Homes by 2020. Box House featured on the new Grand Designs spin-off (known as Grand Designs: The Street) in April 2019.

The clients for Box House wanted to be involved in the construction of their house and were interested in the benefits associated with prefabricated (off-site) housing. However, conventional off-site delivery solutions do not readily facilitate on-site client involvement, as they tend to involve heavy lifting equipment and specialist knowledge. Thus, the Box House brief required us to reduce everything to a human scale.

As a direct response, Studio Bark developed an innovative system of flat-pack timber building boxes, known as U-Build. The box modules were simple enough to be built by the client, but complex enough to perform the many requirements of a building envelope, and meet the stringent tests of the structural warranty provider. The flat-pack U-Build system is modular, flexible and can be ‘nested’ onto standard sheets of plywood, resulting in minimal wastage.

As a flexible modular prefabricated system, U-Build offered some compelling advantages, allowing the house to grow in phases and designing-out the need to move every few years as requirements change.

The U-Build pieces can be cut in batches at a local CNC company, delivered by small vans, and assembled on site using simple tools and commonly available fixings. The resultingsystem has no requirement for lorries, cranes, warehouses or factories, and can be run as a ‘just in time’ process.

The two bedroom, 95 sqm house took around 100 cutting hours in total. The project was constructed solely using manual handling techniques by the client with the assistance of Studio Bark and a small team of architecture students.

Sustainability:

Whole life costs were reduced through a robust 'fabric first' approach including high-levels of insulation and inherent airtightness.

All windows were triple glazed, U-values were at passivhaus levels 0.15 Wm2K and airtightness is also predicted to be at passivhaus levels. The house benefits from a green roof and 2kWp solar panel system.

The insulation is so effective that the building does not need radiators; a single loop of 22mm copper pipe is sufficient to provide background warmth, saving cost, materials and maintenance. The copper pipe was surface mounted above skirting level, also providing a design feature that did not intrude upon the finished positions of furniture.

The supply chain uses materials with environmental certifications, including FSC and PEFC, such as Riga Birch plywood and WISA spruce plywood. Other non-toxic, ecological materials are specified including sheep’s wool insulation.

Material Used :

1. U-Build fabricator/supplier: Cut and Construct

2. Bathroom installation and heating system: Anthony Gregson

3. Breather membrane and tapes: Illbruck

4. Cladding stain and interior finishing: Osmo UK

5. Electrician: Alex O’Cleary

6. Exposed copper pipework and heating system: Jamie Johnstone

7. Glazing: Spectrum

8. Green roof: Eco Green Roofs

9. Photovoltaic solar panels: Oxford Solar PV

10. Roofing subcontractor: Hambro Roofing

11. Roofing supplier: Sarnafil