Tigg + Coll Architects’ extension future-proofs the home of two young boys suffering from a rare condition that will change their needs as they grow
Theo and Oskar suffer from Duchenne muscular dystrophy, a genetic condition causing progressive muscle weakness that will change their physical needs over time.
London-based Tigg + Coll Architects won an international competition to radically remodel the family’s cottage, in Box Hill in Surrey, to create a spacious and adaptable interior sympathetic to the children’s gradually reducing mobility and interaction with their environment.
The initial budget, around £100,000, was not considered enough to extensively reconfigure the cottage, so the architect proposed a wraparound extension with a new accessible entrance.
The open layout features an entrance hall with level access, two large bedrooms for the boys with full height sliding glass doors providing views onto the garden, a large wet room and accessible WC, and a spare bedroom for carers or a guest. The kitchen and family room were relocated to the middle of the plan and open out into the rear extension to improve natural light and connection to the garden.
Key to the transformation is an expansive flat timber roof designed to unite the extension, with its stepped corner glazing and various internal uses, as a single element, and to create a cantilever for a covered veranda for the boys.
Collaboration with contractor developer Ballymore and its project management and procurement team, which donated services, time and materials to the project, created an opportunity to use advanced prefabrication techniques rarely seen on domestic jobs. The free-spanning diagrid roof was developed in collaboration with structural engineer Engenuiti and glulam manufacturer Buckland Timber. The 550mm-deep beams thin out towards the edges and extend to a maximum 5m from the building line at the longest point of the cantilever. Concrete sandwich panel walls pre-fabricated by Byldis & Hurks Facades support the roof deck.
An expansive flat timber roof is designed to unite the extension and create a cantilever for a covered veranda for the boys
Offsite techniques helped ensure accuracy and speeded installation. The commercial scale of the elements might have seemed out of place on another domestic job, but not here, says Helen Sutton, associate at Tigg + Coll: ‘The extension had to be big to accommodate the large accessible rooms and the 100m-long garden, could withstand the scale. There is also a nice contrast with the interiors of the existing house, where the low ceilings open up into the extension.’
The solid timber soffit can be exploited to adapt the internal layout and support the use of hoists or other supports. Diamond shaped openable roof lights in the lattice above the boys’ bedrooms improve light and ventilation.
The architect consulted occupational therapists from the local council on future proofing the property. Interior features include large turning circles and sliding instead of swing doors for wheelchair access, widened openings in the existing cottage, and textured floor surfaces to ensure slip resistance.
The family’s decision to adapt their house will mean they can enjoy it for as long as possible without having to move or rely on external support. ‘It’s about future proofing the house, but at the same time adding warmth and interest,’ says Sutton. ‘It was very satisfying after the project was handed over to see the boys settled in and excited to have their own bedrooms and play with friends unrestricted,’ she concludes.