Sustainable Holiday Cottage

'Recycling' existing buildings by adapting and converting them is one of the main themes of historic building conservation and a key to sustainability. Yet old buildings are all too often seen as a hindrance to energy conservation and carbon reduction and the enormous amount of embodied energy in our existing building stock is largely unacknowledged.

This listed salmon watch tower and adjoining donkey shed on a remote part of the Northumberland coast were derelict when purchased by the current owner, who painstakingly restored them to provide a small holiday cottage. However, as the property has never had mains electricity or water, a private borehole water supply had to be formed, with a woodburning stove providing the only source of heating. Various strategies for obtaining electricity have been tried, including photovoltaic panels; some years ago permission was granted for a wind generator mounted on the tower, but after this was blown down in a gale, a diesel generator had to be used.

We carried out a review of renewable energy options and designed an extension to provide a much needed draught lobby, downstairs bedroom, sunroom (providing passive solar gain) and wc; the single-storey timber-boarded extension preserves the utilitarian character of the building and leaves the tower as the dominant visual feature. The design included sheep's wool insulation, solar water heating, underfloor heating and rainwater harvesting to reduce the load on the borehole; the owner has gone on to install an unobtrusive new free-standing wind generator, photovoltaic panels, and an air-source heat pump to make the improved cottage even more sustainable and liveable.

The construction of most of our historic buildings was broadly sustainable and despite some conflicts between heritage and environmental conservation many existing buildings, like this one, have unrealised potential for energy conservation and zero carbon solutions.