Heather and Paul’s 1930s semi in East Hagbourne, Didcot, had charm – but also its challenges. The bedroom was prone to damp and mould, the heating was unreliable, and their ageing gas boiler wasn’t keeping up. They wanted a long-term fix to make the home more comfortable now, and ready for the future.

A home with potential – and some cold spots

Heather and Paul’s semi-detached home combines original 1930s features with a modern two-storey extension, built in 2012. The extension houses the kitchen and master bedroom – but despite the newer build, some areas of the home remained difficult to keep warm.

During winter, condensation formed where the sloped ceiling met the wall in the bedroom, leading to black mould. The heating system also struggled to maintain a steady temperature. Heather and Paul wanted to fix these issues, reduce their carbon emissions, and make their home feel better to live in.

A Whole House Plan to guide the way

Their initial assessment revealed common issues for homes of this age and type – including cavity walls and suspended timber floors, both contributing to significant heat loss. The team at Cosy Homes Oxfordshire developed a Whole House Plan, clearly setting out where energy was being lost and what could be done to fix it.

The plan helped Heather and Paul prioritise improvements, understand carbon impacts, and make informed decisions – all with the support of their dedicated Retrofit Coordinator.

Watch Heather and Paul talk about their experience in this short video:

A low-carbon heating upgrade

The most significant change was replacing their gas combi boiler with an Air Source Heat Pump – a low-carbon heating system designed to provide steady, consistent warmth throughout the home.

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“The Whole House Plan gave us a clear, holistic view of where we could make improvements. It was well structured, with a summary and detailed options – including carbon footprint info.”

Heather Comina, Didcot

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Rather than switching to underfloor heating, Heather and Paul opted to keep their existing radiators and hot water tank. The heat pump was installed outside, alongside their existing solar PV system and battery storage.

Tackling insulation and condensation

To ensure the heat pump ran efficiently, the team also improved the home’s roof and cavity wall insulation. These upgrades not only boosted energy performance but also resolved the damp and mould issue in the bedroom by reducing heat loss and condensation.

A home that works better, all year round

Heather and Paul’s retrofit has transformed their home into a warmer, healthier, and more environmentally friendly space. By combining a heat pump with insulation upgrades and clear guidance from Cosy Homes Oxfordshire, they were able to reduce carbon emissions and improve day-to-day comfort – all while making use of what they already had.

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“Excellent value for money – and I’ve already recommended Cosy Homes to several others.”

Heather Comina, Didcot

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