This detached house on one acre of land in one of the most prestigious pockets of London’s Green Belt is developed by Emerald ECS with an ambition to introduce the highest international zero-energy and passive-house standards to the UK hi-end residential market. The key objective of the project has been to achieve the lowest levels of energy consumption along with the highest degree of comfort and quality of space. Some of the applied solutions are cutting edge for a residential project in the UK, e.g. zonal heat recovery units in lieu of fan-coils. Other technologies include - to name a few - geothermal heat pumps as the main source of energy, photovoltaic panels, energy storing, rainwater and grey-water harvesting, LED lighting. The external walls are Insulating Concrete Formwork (ICF) with triple-glazed windows. All U-values meet or exceed the Passive House requirements. Our client acquired the land with planning permission already agreed, which determined the “historic” look of the building. We embraced the challenge, finding solutions that will allow us to create an uncompromising traditional appearance with modern materials. The external walls are clad with thin brick tiles and composite sandstone on polystyrene slabs; we worked closely with the manufacturer to develop all the details. The roof is a sophisticated mix of real and PV slates looking identical. The two-storey house does not appear massive, however a large basement with a swimming pool, spa and lounge areas, staff apartment and the “engine” of the house – the main plant room – are all spread below the beautifully landscaped garden. The internal space flows smoothly around the central stair, with a vacuum lift in the centre.