Scoop aims to maximise daylight in a rear extension to a typical Victorian terrace house in London. The brief was to design a highly energy efficient structure employing modern methods of construction. Rather than the recent spate of conservation approved glass boxes on existing structures, the project favours a more sustainable addition with thick insulated walls and ceiling. Daylight from the south facing clerestory window is reflected off the top kitchen cabinets to the ceiling in summer and directly through this window in winter. This clerestory is essentially a light scoop window above the existing garden wall. The roof is folded to fit under existing rear windows and angle up to the south to maximise winter solar gains. The extension follows PassivHaus principles with thick insulted walls and roof, compact plan and studied window orientation. The walls and roof are both made of 200mm SIPS (Structural Insulating Panel) technology with a simliar 200mm foam underfloor insulation, which gave maximum thermal and structural performance without cold bridges.