The Cottage — Full ECO4 Whole-House Retrofit

EmberSol delivered a comprehensive ECO4 whole-house retrofit at The Cottage — a detached pre-1900 rubble stone cottage in Shropshire. This is one of EmberSol's most technically demanding domestic projects, combining four major measures: Internal Wall Insulation, loft insulation, Solar PV, and an Air Source Heat Pump. The property presented the classic challenges of rural pre-1900 solid stone construction: uninsulated walls, degraded loft insulation, and no low-carbon heating or renewable energy generation.

The primary fabric measure was Internal Wall Insulation (IWI) using the SWIP system with Knauf mineral wool batts. Solid stone construction requires particular care with the vapour control strategy — the SWIP Intello intelligent VCL was used throughout, providing adaptive moisture management that allows the wall to dry inward in summer while preventing moisture ingress in winter. This is critical for pre-1900 stone construction where the wall needs to breathe. The IWI installation is documented across multiple elevations from Knauf batts through to completed and decorated rooms.

Loft insulation was upgraded to 300mm Knauf mineral wool, with specialist detailing at the stone gable wall junction. Solar PV was installed on the south-facing pitched roof — MCS certified and G98/G99 compliant. The Solar PV system is designed to work in conjunction with the Air Source Heat Pump, offsetting the heat pump's electricity consumption during daylight hours and reducing running costs.

The Air Source Heat Pump is a Midea monobloc unit — one of the most reliable and efficient ASHP systems available for UK residential retrofit. With a SCOP of over 3.0, the Ecodan delivers over three units of heat for every unit of electricity consumed, making it a significant improvement over the direct electric heating it replaced. The system includes a hot water cylinder and full controls. A DMEV system was installed to maintain healthy indoor air quality. All works were completed under ECO4 with full PAS 2035 compliance and TrustMark lodgement.