House Made By Many Hands is a renovation and extension project by the architectural practice Cairn, which is based across Edinburgh and London in the UK. The studio, founded by Kieran Hawkins in 2018, specialises in envisioning and making low-carbon buildings that can age well, benefiting a broad range of people. Elaborating upon the studio's name and the practice’s overarching ethos, the architects share, "A cairn is made by many hands; the name speaks of the practice’s commitment to making sustainable architecture as a way of building connections and practical knowledge.” The renovation project House Made By Many Hands exemplifies this idea of sustaining a low-impact building for versatile usage whilst also bearing an inkling of several designs and hands on the form and surface of the structure.

The private residence, located on a densely inhabited, car-free street in Victoria Park Village in Hackney, east London, is a Victorian house. The two-storey terraced residence is seated on a constrained site, offering no rear garden and only a narrow strip of external space. Before Cairn’s intervention, the residence was small and cramped, with very little natural light reaching the ground floor. Given that the client is a professional chef, with a background in sustainable agriculture, the kitchen and dining areas within the residence, too, were rather compact.

“The challenge was to work with what was there, designing as sustainably as possible through reuse and repurposing of existing materials to bring it up to modern day standards,” Hawkins shares. This also meant that the architects had to demolish certain parts of the house. “Carefully chosen sections of the brick structure at the rear of the house were demolished. We retained whatever we could of the structure to minimise embodied carbon,” Hawkins shares.

The renovation of the space alters the ground floor, positioning the kitchen as the most spacious and standout feature within the residence. This was ensured by the removal of certain walls in this zone and the lowering of the floor to improve head height. Further, there are no internal doors on the ground floor apart from that of the bathroom. This ensures that the spaces are not segmented into smaller zones. Instead, the internal zoning is defined via considered placement of structured piers and the changes in floor levels. Apart from offering an expanded space for the kitchen and the living area, these interventions also enhance visual connections between the living area, kitchen and the outdoors. Meanwhile, renovations on the upper floor include changes to the home office and new access to the roof terrace.

To open up the space to welcome more light, it was also required of the architects to install a lightweight perforated material towards the edge of the structure, which could serve as an extension to the original construction. Instead of utilising steel for this purpose, Cairn installed a hardwood frame and pioneered the usage of a new low-carbon concrete, which generates nearly 30-40 per cent less carbon dioxide in its production than standard Portland cement. Timber performs the same functional role as steel, albeit in a more graceful and sustainable manner. The usage of concrete, on the other hand, was unavoidable due to certain constraints on site. Hence, Cairn resorted to the usage of low-carbon concrete.

This structure is also the first building in the UK to use a low-carbon limestone calcined clay cement (LC3) concrete. Cairn could undertake this experimentation because of their environmentally conscious clients Dora Taylor and Danny Hubbard. “LC3 has the capacity to reduce total global CO2 emissions by 1-2 per cent if adopted universally by the construction industry. The project demonstrates how a Victorian house can be renovated and extended with a substantially reduced environmental impact – 40 per cent lower than a typical build deploying conventional concrete, steel frame box and plasterboard,” Hawkins shares. LC3 is mixed and poured like conventional concrete. Hence, it requires no additional site training. Furthermore, it also bears comparable strength to traditional concrete. Within House Made By Many Hands, it is used for the floor slab as well as to underpin the house’s existing brick footings to help gain an extension in the head height of the floor.

The usage of the hardwood frame—developed in collaboration with structural engineers Structure Workshop—spanning between the brick piers of the Victorian structure, on the other hand, infuses light into the house and helps open up the space by slightly extending the common area outward. To set it up sturdily in place, steel was sparingly used, forming footings and flitch plates at key connections and allowing demountable bolted connections. “Cairn worked closely with structural engineers Structure Workshop, using the practice’s copyrighted Carbon Calculator to make embodied carbon calculations, informing the choices and quantities of materials,” the studio shares.

The lining layers for the installation of the wood frame were omitted where possible, for the structure and frames to visually dominate the ground floor. The wood boards are also accompanied by breathable woodwools, finished with a lime render. The (wooden) extended roof supports patent glazing, which means that this covering is not completely opaque. On the contrary, this setup significantly enhances the daylight levels on the ground floor. Additionally, a new roof light above the bathroom and several new openings puncturing old and new walls illuminate the space.

Most new materials used by Cairn are bio-based, specified to improve the health and well-being benefits of the residents and the environment. These include wood, hempcrete, LC3, cork, wood fibre, wood wool and lime plaster. One can find worktops made out of recycled waste wood products in the kitchen, made by Foresso, which adds a warm and earthy texture to the home.

Beyond the usage of a few new materials, Cairn fundamentally relied on reusing existing materials on-site. While all essential and usable elements from the original construction were retained, the newer construction, too, was done with extreme caution, ensuring that the new does not encroach upon the old inordinately. Further, various energy-saving measures, such as the retention of the combination boiler and the installation of double-glazed windows, ensure long-term reduction in energy consumption. The post-construction furnishings also feature reused materials, including timber flooring reclaimed from Bow Magistrates Court and a collection of various pre-used furniture and light fittings.

Emulating the collaborative ethos of the studio, this project also witnessed the close participation of the client and her partner, who, alongside the architects and contractors, helped cast the hempcrete walls (hempcrete infill within the timber frame) by hand. Hawkins shares, “The decision to make the walls by hand, replacing power tools with human energy, resulted in a rewarding collective activity and a project made by many hands: the hands of the architects, engineers, contractors and the client. This collective endeavour was echoed in the site hoardings which were printed with a montage of sketches on the theme of the House of the Future by pupils of the adjacent primary school: a hoarding made by many hands.”

Project Details

Name: House Made By Many Hands
Location: Victoria Park Village, London, UK
Client: Dora Taylor and Danny Hubbard
Architect: Cairn
Design Team: Kieran Hawkins, Riccardo Bela
Contractor: David Sheard Ltd
Structural Engineer: Structure Workshop
Kitchen Joinery: Xylo
Gross Internal Area (Renovations): 70 sqm