GB004 Sutton Dwellings

📍London, United Kingdom

In 2019, Clarion Housing Group decided to refurbish Sutton Dwellings – a historic estate in Chelsea built in 1913. It is one of the first examples of affordable social housing in the UK.

The group stripped back and remodelled four mid-rise tower blocks on the Sutton Dwellings estate, which had been derelict for many years, into homes suitable for families.

Installing ground source heat pumps instead of gas boilers in the Central London properties has reduced carbon emissions by around 70%. Since ground source heat pumps produce no point-of-use emissions or pollution, Clarion Housing Group has protected local air quality in this urban area.

Commercial Director for Social Housing at Kensa, Stuart Gadsden, comments:

“ This significant installation dispels many myths about ground source heat pumps, demonstrating their suitability for older buildings and dense urban locations. But, most importantly, it provides Sutton Dwellings residents with a super-efficient, clean, affordable, zero-carbon system to keep their homes comfortable and warm all year round. ”

Sutton Dwellings was built in 1913 as a forerunner to council houses and provided homes for more than 2,000 people.

Over the last decade, as the estate gradually became unfit for purpose, there were discussions about whether to demolish and rebuild it. However, the decision was made in 2019 that Clarion Housing Group would refurbish and modernise the estate instead. It worked with residents for over a year to come up with a new plan.

Lessons learned

• Heat pumps also work for historic housing as well as social housing
• Individual heat pump installations aim to mimic gas infrastructure to improve user satisfaction and easiness of transition.

Key facts

Description of the technical concept

Installer aims to mimic gas infrastructure to improve user satisfaction and easiness of transition. Individual ground source heat pumps are installed for each apartment, with 27 boreholes providing for 81 apartments. Ground source heat pump boreholes are vertical ground arrays or collectors used to extract heat energy from rock to a ground source heat pump.

Kensa designed the ground source heat pump system, supplied the heat pumps and cylinders, and oversaw the drilling, headering, and trenching of the ground array, including the boreholes and tails at the base of the riser.

As the site is in Central London in the heart of the Royal Borough of Kensington and Chelsea, there was limited space for drilling and other trades on-site. Kensa carefully coordinated the project and the team frequently moved a mobile drilling rig onto the road to access different areas of the site.

Technologies used:
62 x 3kW Kensa Shoebox
& 19 x 6kW Kensa Shoebox heat pumps

Installing ground source heat pumps instead of gas boilers in the Central London properties has reduced carbon emissions by around 70%. Since ground source heat pumps produce no point-of-use emissions or pollution, Clarion Housing Group has protected local air quality in this urban area.

The annual running costs of the heat pump systems range from £301 for a 1-bed flat to £712 for a 4-bed flat, averaging £441 per property, based on designed loads and a 24.5p/kWh unit electricity price. The costs for end users are estimated to be similar or even less compared to the previous system of a gas boiler. This cost aspect is crucial especially since this is a social housing property and inhabitants are at high risk of experiencing energy poverty, and here the sustainable energy transition is not harming but helping them.

GB004 Sutton Dwellings

Case study delivered by: Kensa