Housing 21

Ground source review: Housing 21

Residents in 26 self-contained flats at a retirement community in Norfolk had their inefficient communal boiler replaced with individual Shoebox ground source heat pumps.


  • Large-Scale Project Award, Regional Energy Efficiency Awards 2022.
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Project overview

Kensa replaced an inefficient and failing communal oil boiler with networked ground source heat pumps installed within each individual flat in a block at Robert Smith Court’s retirement community in Norfolk.

The site benefitted from flat, open access with ample space for drilling, which mainly took place within grassed areas, although some trenching over the car park areas, to connect boreholes was required. The ground was made good in areas where drilling and trenching took place, and the boreholes are visually unobtrusive.

This has given tenants efficient, sustainable and reliable heating and hot water, which they have complete control over. As well as having a positive impact on their fuel bills, the system is also saving Housing 21 in maintenance costs due to its low lifetime ownership costs, as well as cutting their carbon footprint.

With rising energy costs becoming a mainstream issue, there is a growing need for social housing providers to ensure replacement heating systems deliver the lowest possible running costs. Ground source heat pumps currently provide the lowest carbon heat and further reductions in the planned carbon intensity of electricity generation mean further savings are expected.

Robert Smith Court       







Ashley Norwood, Property Services Manager within the Asset Management Team at Housing 21, said: “Our aim was to be a leading organisation with our sustainability aspirations. The main focus now is ensuring our carbon footprint is managed efficiently and we are investing in new technology for our homes to avoid using fossil fuels where possible.”

Benefits to tenants

  • Tenants are now fully in control of their own heating and hot water.
  • They all have their own thermostats and time clocks plus TRVs on the radiators. This means they can adjust temperatures to suit more easily and so they are more comfortable.
  • Tenants can also switch electricity supplier whenever they want.


  • Maintenance costs are reduced for Housing 21.
  • Despite fuel costs rising across the board, running costs have reduced for the residents compared to what they were paying for the oil boiler.
  • Carbon emissions significantly reduced – by at least 60% which will only increase year-on-year as the electricity grid continues to decarbonise.
  • The potential for maximising revenue as the properties are more marketable to let, due to future-proofing with sustainable technology and running cost savings
  • Low lifetime cost of ownership
  • Removal of all local NOx emissions to improve air quality
  • SAP improvements to existing EPC ratings








Ashley Norwood, Property Services Manager within the Asset Management Team at Housing 21, said: “We’re thrilled that all of our 20,000+ properties across the UK have reached an Energy Performance Certificate (EPC) status of C, thanks to the sustainability measures that we introduced to reduce our carbon footprint. We are delighted to have achieved this major milestone eight years ahead of the Government target.”

Key Facts

  • Retirement community
  • 26 self-contained flats in the block
  • Shoebox ground source heat pump
  • 20 boreholes with a combined borehole depth of over 2,600 metres