Interactive floor plan: Painted House, London

Imaginative re-use is rarely concluded on such a grand scale. The Painted House in North London stems from an unprecedented opportunity tucked away on a quiet residential street. Tasked with reconfiguring two 1940s semi-detached houses for a large extended family, Jonathan Woolf Architects, working with Bharat Patel, have cleverly conjoined the structures at key points.

By using large opening doors that fold seamlessly away when openness is desirable, the two houses can also be kept separate and discreet. Created for two brothers, their families and grandparents, this is highly architectural exploration of an increasingly common housing type, usually constructed on a very pragmatic and informal basis.

From outside, the houses have been subtly re-skinned in slips of thin brick, disguising the fact that they've been entirely reinsulated, restructured and rebuilt. Stripped of extraneous detailing, with large expanses of mullion-less glass, the prosaic nature of 1940s-era construction is given a subtle contemporary sheen; almost unnoticeable at first, but gradually becoming evident in the care and placement of ironmongery or the crisp precision of the brick courses.

The interior is also an exercise in refinement, with every surface and intersection pared back to the bare minimum. That's not to say this is a Minimalist project, for the delight in light and form animates both the house and the interplay between circulation spaces and the individual rooms. The house's name stems from a preoccupation with painted surfaces; there is an immensely careful interplay between the expansive, unbroken wall and floor planes, modulated by a variety of discreetly different shades of paint.

The rear façade features generous openings onto the garden, while a new attic floor has been carved out of the original volume, the joists and trusses enclosed to form sculptural living spaces. Clever details abound, like the passive ventilation systems that direct cooled or heated air around the space, or the placement of the fan motor for the kitchen hob - which is tucked away so that the fan operates in ghostly silence.

The house is a blank canvas for busy family life, a stage set waiting to be animated. Woolf's studio was established in 1991, demonstrating a concern for calm and considered residential works that acknowledge vernacular traditions, and the Painted House continues this low-key but critically assured line of work.