A young couple decided to settled in a rural area, and to start their building project around the walls of an old cow shed. Interested in a holistic approach to architecture, their brief was that the house should fit harmoniously in its context, use locally harvested materials where possible, and be an exemplar in terms of environmental performance. The finished house reuses original materials while achieving annual carbon emissions of 9.1kgC02/annum, equivalent to an Energy Rating of 89, through the high efficiency envelope and ground source heating systems. The design in organised around a structural timber frame, offset with the retained lower walls of the original shed. As environmental performance was fundamental, to avoid infiltration, arising out of frame movement over time, the shell of the house is fully external to the frame, providing structural stiffness to the frame (thereby reducing the requirement for extensive bracing internally), and providing a highly insulated, air-tight envelope. In other words, - the frame gives strength, the envelope gives stiffness. The new house is glazed to the south for passive gains to the living / dining area, and accessed from the north away from prevailing winds. The foot print of the house occupies two thirds of the original barn, the remaining third left as a sheltered courtyard to the north. The building is clad in British Larch, and any of the materials used in the original cow barn were reused, including 90% of the steel frame and much of the original brick. The same palette of materials are used internally as externally.