Sylvanus House


A compact tree-top house situated on a sloping site in Highgate Cemetery is surrounded by a nature reserve and a tree-lined lane. The house takes its form from the sloping site. A gently twisting structure, the house opens up towards the winter sun. An overhanging roof canopy controls the summer heat gain. From the top floor terrace a magical, shimmering panorama of London can be seen at night through a veil of trees.

Previously the building was in a very poor state, with twin garages on the ground floor and a tiny spiral staircase leading to a dark and depressing single-floor apartment and rooftop conservatory. It was bought in 2002 by the owner of 85 Swain's Lane, who we were already working for, so that we could close up the first floor window that overlooked the roof of 85 Swains Lane, and that was preventing our client from increasing the height of 85 Swains Lane. 

In 2002 we began work on proposals to re-configure the house with bedrooms on the first floor and to add a second floor that would provide the principal reception space. At the same time, we tried to persuade our client to upgrade the house and convert it to the Passivhaus standard or at least to the Passivhaus Enerphit retrofit standard which we had recently learnt about through a German employee interested in the radical approach Justin Bere was taking on his own house at Newington Green. In the end, money was saved for the 85 Swains Lane re-build that followed, and 87 Swains Lane was given two bedrooms and an additional floor, but the two garages were not converted in order to keep space for the owner's car and collection of motorcycles while 85 was rebuilt; and the environmental improvements were limited to a thin cladding of insulation, double glazing, and a heat recovery ventilation system.