The background
It was clear these homes would benefit from both insulation and ventilation to reduce their carbon emissions and improve thermal comfort.
We take a fabric first approach to retrofit where possible, meaning we look to insulate and ventilate first and install renewables second or where we cannot achieve an EPC C or above with fabric improvements alone.
The homes were also eligible for renewable measures such as solar panels and domestic heating improvements of Air Source Heat Pumps for an energy efficient home. Work was completed between April 2024 to March 2025.
The process
We established a strong working relationship with our retrofit installers and a robust quality framework, including a combination of site visits, regular Partnering Progress meetings and other follow-up activities. We engage continuously with residents via online surveys, face-to-face discussions, and dedicated feedback events to ensure their satisfaction with the quality and progress of works.
The measures
- New extractor fans for kitchens and bathrooms
- Door undercuts
- Trickle vents
- Lap vents
- Loft insulation
- Cavity wall insulation
- External wall insulation
- Solar panels
- Air source heat pumps
- Roof vent tiles
Loft insulation
41 complete
Ventilation
98 complete
Air Source Heat Pump
98 complete
Solar panels
98 complete
Cavity wall insulation
476 complete
The result
All properties reached an EPC of at least C after the work. One property was even taken from a D to a mid-band A.
See below for examples of installation costs, and subsequent savings for the resident.
Case studies - Northbourne, Surrey
Northbourne is an estate in Farncombe, Surrey. We own all 129 homes, and we completed extensive retrofit work to 85 homes. Homes are made up of one-, two- and three-bedroom properties. Work included fabric measures, new heating systems and solar panels.
We contacted our residents in Spring 2024 to explain and discuss our retrofit plans and arranged for a retrofit assessor to complete an assessment. The assessment is a detailed inspection of a home to identify ways to make it more energy efficient.
The qualified assessor looked at:
• Fuel bills, carbon emissions, and comfort and health
• The condition of the home. This involved inspecting the inside and outside of the home, including the roof, doors, windows, walls, and heating system. They also looked for any signs of damp or mould
• The architectural design considering the construction and structural integrity of the home.
The measures we completed were:
• Air source heat pump
• Door undercuts
• New extractor fans in kitchen and bathroom
• Loft insulation
• Solar panels.
The retrofit work started in November, and our retrofit installers finished the work of February 2025.
Our Sustainability Engagement Lead visited Brett and Sian Neaves to find out how they had found the retrofit process and to ask if they thought it was beneficial.
Brett and Sian were the first residents to move into the newly built estate 30 years ago.
They said they love the new Air Source Heat Pump. They have never had a central heating system before, only storage heaters which had no control system.
The work took two days with a further three to compete any snagging issues. The electricians were brilliant, and the management team were hard working and approachable.
Brett and Sian said it was worth working with Southern Housing and putting up with a week’s upheaval as the result is so positive.
We replaced storage heaters with an air source heat pump, we also installed solar panels.
The benefits of installing heat pumps and solar panels together include reduced energy costs, a more sustainable energy supply. Solar panels generate clean, free electricity from sunlight, which can be used to power the air source heat pump, reducing reliance on the grid and potentially lowering electricity bills.
This combination also enhances energy efficiency and contributes to a greener home, reducing carbon emissions.
The Retrofit Delivery Team supported residents to access to the Smart Export Scheme which allows those with solar panels to sell any excess electricity generated back to the grid. Residents can earn money for each unit of electricity you export, according to the SEG tariff offered by their chosen energy supplier.
Resident David said his home is much warmer, and the water pressure is much improved. He told Jo his bath now fills up in 10 minutes rather than the previous 30 minutes and is really hot.
David can now control the temperature in his home using the heating app on his phone which our contractors helped him set up.
He said he used to put £20 every two weeks on electric now he only uses £10.
He has been able to increase his savings and is using the money he has saved to take his son on his first foreign holiday for his 18th birthday in May.
David said the work was not too disruptive and he didn’t experience any issues. The installers always kept him informed and tidied up afterwards.
Work was completed in November, and Mr and Mrs Peach said it was two very long days. The plumbers took one day to install the new air source heat pump and were in their home all day, so they said be prepared for some disruption.
The couple said they cleaned out their airing cupboard and emptied shelves in the work area before work started. This allowed for a smooth start to the work.
They said the benefits of the work were huge. Their home is now much warmer and retains its heat for longer. Their bills have reduced, and they now have constant warmth and a good ambient temperature in their home.
The contractor helped Mr Peach set up the solar app on his phone and explained how it worked. Both residents said the installers were very good, friendly and polite.