Knox Bhavan completes energy-efficient and accessible house using prefabricated timber cassette system
Edmund Sumner

Knox Bhavan completes energy-efficient and accessible house using prefabricated timber cassette system

16 May 2024  •  News  •  By Gerard McGuickin

London-based architectural practice Knox Bhavan has completed an energy-efficient and accessible house for a client with particular physical requirements. Located on a lane in a village in Hertfordshire, England, “The Little Big House” utilizes a bespoke, prefabricated timber cassette system.

photo_credit Edmund Sumner
Edmund Sumner

The client, Henry Fraser, is a mouth artist, author, and motivational speaker. A life-changing accident in 2009 left Henry paralyzed from the shoulders down. In 2015, he taught himself how to paint by holding utensils in his mouth: an iPad stylus to start with and later, as his health improved, pencils and paintbrushes attached to a mouth stick. Henry’s 2017 memoir, The Little Big Things, is now a West End musical and lends its name to “The Little Big House”.

photo_credit Edmund Sumner
Edmund Sumner

Following Henry’s accident, Knox Bhavan adapted his parents’ house pro bono. The availability of a plot for sale on the lane presented an opportunity to design a purpose-built house, one that would allow Henry to live independently with support from his carers. The Little Big House replaces a poorly-built 1950s chalet bungalow. “Retrofitting the original property presented significant obstacles in fulfilling the client’s brief, particularly concerning space and circulation,” says the studio. The plot is located in a green belt area (where building is typically restricted) — Knox Bhavan presented the case for the site’s redevelopment with a thorough and long-lasting design. The new house is equivalent in size to the original property.

photo_credit Knox Bhavan
Knox Bhavan

The house makes use of a prefabricated timber cassette system developed by Knox Bhavan in partnership with modular digital manufacturing company BlokBuild (the home’s timber frame contractor) and engineers Price & Myers (the timber frame engineer). The OSB (oriented strand board) prefabricated system was developed for Knox Bhavan’s “March House” project, a home on the banks of the River Thames in the town of Marlow, England. Describing the system, the studio explains: “At March House [the cassette forms] were made of two OSB layers separated by fin joists to give a 290-millimeter section, with 250 millimeters of Rockwool insulation sandwiched between . . . the beauty of the system is that it was used for walls, floors, and roof. We did not have to pour a ground slab, so it’s good for the carbon footprint — we could even insulate soffits of floor cassettes” (Kucharek, 2022). The system can be tailored to the client’s brief and site context, resulting in a high-quality, energy-efficient product.

photo_credit Edmund Sumner
Edmund Sumner

Henry Fraser’s commitment to environmental responsibility necessitated the design of an energy-efficient home; at the same time, he required a controlled interior environment to help stabilize his body temperature. The prefabricated cassette system provides a number of notable benefits, including: minimal construction waste, fast erection, improved insulation, and enhanced thermal performance. The house is oriented to maximize solar gain in the winter months — its massing and form were influenced by the sun’s seasonal movements, ensuring ample natural light reaches into the interior. Moreover, photovoltaic panels were placed on the south-west facing roof and Knox Bhavan incorporated a small green roof. The structure’s design makes use of durable materials that can withstand inclement weather, including SiOO:X larch timber for the elevations. (SiOO:X is a Swedish patented and ecological wood protection system.)

photo_credit Edmund Sumner
Edmund Sumner
photo_credit Knox Bhavan
Knox Bhavan

Knox Bhavan designed The Little Big House with a characterfully large, sweeping roof — a 12-degree pitch creates an airy volume over the main living spaces and provides cover to the front entrance. The soffit is clad in a reflective aluminum, accentuating the roof’s floating aspect. The home’s stepped-back upper floor ensures it maintains a low profile when viewed from the front driveway. “With a T-shaped plan arranged around two courtyards, the house is lateral in its design, with expansive open-plan rooms to accommodate wheelchair use,” says the studio. “The ground floor is designed around the turning circle of Henry's wheelchair, allowing him to move about the entire space with ease.” 

photo_credit Edmund Sumner
Edmund Sumner
photo_credit Edmund Sumner
Edmund Sumner
photo_credit Knox Bhavan
Knox Bhavan

Interior pocket doors allow spaces to open up and expansive glazing throughout the house offers a seamless connection to the outdoors. A customized bedroom, bathroom, kitchen, double-height dining space, intimate TV snug, and adjoining bright studio are located on the ground floor; a carer’s bedroom is also on the ground floor level. A lift (elevator) provides access to the upper floor with two bedrooms for a second carer and guests, a small bathroom, and a separate carer’s kitchenette.

photo_credit Edmund Sumner
Edmund Sumner
photo_credit Edmund Sumner
Edmund Sumner
photo_credit Knox Bhavan
Knox Bhavan

The Little Big House was awarded both the 2024 RIBA East Award and 2024 RIBA East Project Architect of the Year.

Site area: 721.6 square meters (approx. 7,767 square feet)

Gross internal area: 225.5 square meters (approx. 2,427 square feet)

 

Reference:

Kucharek, J.-C. (2022) Making buildings: Knox Bhavan on Timber Cassette Construction at March House, Marlow, RIBAJ. Available at: https://www.ribaj.com/intelligence/making-buildings-knox-bhavan-on-timber-cassette-construction-at-march-house-marlow (Accessed: 16 May 2024).