Comprehensive upgrade of an Edwardian house

This terraced house required a comprehensive refurbishment. The building fabric was upgraded to incorporate extensive energy-efficiency measures, including improved airtightness, ground floor insulation, internal insulation to solid walls, triple-glazing, and energy-saving electrics.

The suspended timber floor at ground level required lifting and replacing. Rigid insulation was fitted between the new joists, and a vapour barrier fitted above for airtightness. The failed concrete floor to the kitchen was relaid, with a layer of insulation between the new slab and screed. External walls were lined internally with 90mm thick rigid insulation, with battens and plasterboard fixed over. The extra wall thickness reduces the room sizes slightly, but by giving careful thought to the furniture layouts and radiator positioning, the rooms feel bigger than they did before.

All existing windows were replaced with triple-glazed composite (timber inside, aluminium outside) units. The extra cost for triple-glazing was fairly small, but the improved performance eliminates cold down-draughts from the glazing, making the house feel considerably warmer.

A full new central heating system was installed. The installed combi-boiler is solar-compatible: it can use pre-heated water from solar panels should these be fitted at a later date. The house was fully re-wired. The wiring includes two circuits which can be switched off using switches in the hallway, reducing energy use by devices on standby. Photovoltaic panels were not fitted, but wiring was included to allow them to be retrofitted easily.

The performance of the completed building exceeds current building regulations, and annual energy bills are at least 50% lower than an average house of its size.