We were originally asked by the Clients to remodel and enlarge small 1950s townhouse standing on a pleasantly secluded south-facing plot. But after some analysis it became obvious that poor quality and modest size of the original house was making it unviable for transformation into a comfortable residence. Demolishing the original house and building a new modern house in its place was the only possible alternative. We prepared the designs, negotiated and obtained planning permission for demolishing the existing house and building a new larger one with large new basement in its place. The new house has more than double the floor area of the original one. It is of extremely high environmental standards, with comfortable and spacious floor plans and is of inoffensive design that sits tactfully between its neighbours offering harmonious addition to the Conservation Area. To achieve continuity of the streetscape the construction materials chosen for the new house are referencing the prevailing materials of the neighbouring houses. The design allows the house to assert it own visual identity, but without jarring contrasts to its immediate neighbours. The front facade finished in visually heavier masonry with relatively small window openings is more enclosing in appearance, while the private rear facade in mainly white render and glass opens the house to the southern sunlight, to the private rear garden and to the attractive views beyond. Placing all family areas and most bedrooms on the warm and sunny south-facing rear side and the services and auxiliary areas on the colder north-facing front side contribute to the energy efficient floor plans. Extensive energy-saving measures include a bank photovoltaic panels supplementing the normal electricity supply and offsetting 1.5 tonnes of CO2 per year. The interior design fit-out was carefully designed to express and complement the modern, sustainable and energy-conscious ethos of the new house. The styling and the natural materials chosen create comfortable light-filled contemporary interiors of timeless character.