The 80m 2scheme will create a new kitchen and living, dining and family areas at the rear of a turn-of-the-century house in a conservation area in Richmond, south-west London.
The design features a 2m bronze and steel canopy, laser-cut into a pattern inspired by one of the client's dresses.
According to the project architect, Tom Teatum, this canopy will produce continually changing lighting conditions within the new extension.
'In a way it is a large sundial,' said Teatum. 'It is also like a classic Victorian room, which is animated by the way in which light comes into it.'
The extension, which received planning permission in November last year, is expected to be finished in June.