A young family of four, have commissioned FPA to extend their steep roofed cottage in the suburban town of Purley, Croydon. This project offers the opportunity to revise and refine concepts and principles that FPA had outlined in the design of their house extension project in Surbiton and similarly, here too, the project is split into two separate sub-briefs and organised, once again, around two distinctive new buildings. The side extension is monolithic, with hollowed-out apertures and finished in dark painted render to harmonise with the somber bricks and accommodates ancillary functions. The back extension is conceived as a spatial sun and light catcher. An architectural nacre piece is hung indoors to "catch the light" from nearby sources. A precise study of the sun path has inspired the careful insertion of openings of different types and shapes to direct one's view towards the outside. The new building is articulated by 'pulling' and 'stretching' its edges to produce a dramatic sculptural interior. The back extension is clad with three-dimensional textured timber boards to produce heavy shades and augment its sculptural properties, creating a stronger relationship with the mature trees at the end of the back garden.