Social Housing Retrofit

Kensa works closely with social housing providers to deliver a sympathetic programme of retrofit ground source heat pump installations with minimal disruption and major benefits, reducing tenant bills and making a dramatic impact on fuel poverty reduction.

Enfield Ground Source Heat Pump Tower Blocks Upgrade Combats London Air Pollution


By pairing Kensa’s Shoebox heat pumps with Shared Ground Loop Arrays, developments featuring multiple dwellings, including flats, can attract external funders to own and operate the ground source heat pump infrastructure, removing the cost of the shared ground loop array from the housing association. In return, the external funder can charge connection fees if they wish.

System Architecture

Kensa’s innovative Shared Ground Loop Arrays link a series of boreholes to multiple properties, including flats, via an ambient temperature distribution system.

Each property then has an individual Kensa heat pump wired to their own electricity supply, which upgrades the low temperature ground heat for heating and hot water within their dwelling.

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The advantages of Shared Ground Loop Arrays in retrofits:
  • Split-ownership of ground arrays provides a funded option.
  • Exempt from Heat Network Metering & Billing Regulations.
  • Extremely low CO2 emissions;
  • Easy carbon & building regulations compliance.
  • No NOx, SOx or particulates emissions.
  • Lowest energy bills – slightly lower than mains gas, significantly lower than air source heat pumps, LPG & oil.
  • Householders able to switch energy suppliers.
  • No district heat losses.
  • Potential for free summer cooling.
  • Scalable and flexible district size can be deployed in sections as the development progresses.
  • Ultra-efficient and reliable.


The Kensa Shoebox Series

  • Suited to flats and apartments and smaller houses
  • Available in 3 – 6kW


Energy Company Obligation (ECO)

Ground source heat pump installations are eligible for ECO funding in retrofit social housing schemes.

ECO places legal obligations and targets on the larger energy suppliers to fund energy efficiency measures in British households.

It is in place to support retrofit efficiency works in the domestic sector, with a particular focus on vulnerable consumer groups and hard-to-treat homes.


Under the rules of ECO, energy suppliers are obliged to fund energy efficiency improvements of their domestic customers’ buildings in three distinct areas; Carbon Emissions Reduction Obligation (CERO), Community Obligation (CSCO), and Home Heating Cost Reduction Obligation (HHRCO).


Split Ownership model

By allowing ‘split ownership’, Government has created a significant catalyst for energy-efficient new build developments featuring Shared Ground Loop Arrays, with costs no longer borne by the housing provider.

This eliminates the key barrier to deployment – the expense of the ground array – and allows Kensa to mimic long-standing ‘split ownership’ arrangements in the gas sector with the underground infrastructure owned and maintained separately from the heat pump installed inside the properties. Kensa’s model sees the housing provider fund the heat pump (which is sold with the property and maintained by the purchaser) whilst the ground array is fully funded.



Developed by Kensa Utilities, for social housing providers with a portfolio of over 3,000 properties. ZERO enables the whole stock retrofit over a phased period of 3-5 years.

This is suitable for social housing providers with serious net-zero ambition with diverse housing stock, eliminating the upfront cost and providing a managed programme that provides a wealth of local benefits and significant Housing Revenue Account savings.

Case Studies: High rise

Tower Blocks

  • Project partnership with Thurrock Council 
  • Three high rise tower blocks in Chadwell St Mary
  • 270 storage heaters replaced with ground source heat pumps
  • Shared ground loop array system architecture demonstrating the potential for ground source heat pumps to rapidly and affordably decarbonise multiple properties at scale
  • £3.2 million from Wave 1 of the Government’s Social Housing Decarbonisation Fund (SHDF) to finance the scheme
  • Estimated to reduce fuel bills by over 50% for some households due to ground source heat pumps being three times more energy efficient

Enfield Tower Blocks witjh Shared Ground Loop Array ground source heat pumps

Social Housing

  • Project partnership with Enfield Councils
  • Over 400 flats over 8 x 12 storey tower blocks in the London Borough of Enfield
  • Electric underfloor heating replaced with Kensa Shoebox ground source heat pumps
  • 100 boreholes ranging from 197-227m deep across 2 sites
  • England’s largest shared ground loop array heat pump system
  • Estimated 773tCO2 saved
  • Tenants’ bills are reducing from an average £800 per year to an average £350

Case Studies: Low rise

Two Storey Flats

  • Project partnership with Hanover Housing Associations
  • 23 properties and a site office over two-storey flats
  • 12 x Shared Ground Loop Arrays
  • Kensa Shoebox 6kW Twin per flat
  • Replacing old inefficient night store heaters
  • Funded by the ECO grant
  • Completed in 10 weeks
  • Winner: Retrofit Project of the Year (H&V News Awards 2017)
  • Winner: Most Innovative Retrofit Scheme (Housing Innovation Awards 2017)

Low Rise Apartment Building


Case Studies: Housing

Ground Source Review Coastline, Wheal Vyvyan 4

Sheltered Housing


General Needs Housing

  • Project partnership with the Flagship Group
  • Mixed development of houses, bungalows and flats
  • 5 x Shared Ground Loop Arrays
  • Kensa Shoebox 6kW per dwelling
  • Replacing electric panel heaters
  • Funded by the ECO grant
  • Completed in 9 weeks

User Engagement

Kensa Contracting offers a comprehensive information and training programme to support residents, Housing Association staff, project and scheme managers, ensuring all stakeholders are engaged and well-prepared and understand the stages of work involved.

Tenant liaison

This support is absolutely key, both to ensure the quality and sustainability of the installations, but also to ensure that delivery is well-managed and hassle-free. Kensa introduces schemes to tenants to make sure they’re aware of what’s involved in a heat pump installation, what to expect, and how the project will benefit them in the long term.

After Care & End Users

Properties featuring Kensa’s Shared Ground Loop Arrays will provide end users with numerous unique benefits over traditional Heat Networks with minimal after care requirements:

Lower fuel bills

GSHP’s produce 3-4kWh of heat energy for every 1kWh of electrical energy used, making them 300-400% efficient. Compare this to a typical boiler, which is just 90% efficient. Kensa’s ground source heat pump systems offer the lowest fuel costs.

Lower emissions

Because a GSHP extracts so much “free” energy from the environment, this enables CO2  emissions to be lower than any other type of heating system.

Minimal maintenance

GSHPs don’t require annual servicing or maintenance, and have an expected lifetime of 20 years.

Energy independence

With an individual ground source heat pump in each property, homeowners are in complete control of their own heating and energy bills, enabling easy energy tariff switching and payment only for their own heat consumption.

Download End User's Guide

house purchasersFree cooling & no overheating

With heat being generated at the point of use (inside each dwelling) the ‘heat’ circulating the property is low temperature, therefore there are no heat losses from the system to contribute to overheating in risers and corridors. The low temperature system also allows for free passive cooling to be introduced, creating a comfortable living environment all year round.

Year round supply

1m below the surface the ground temperature remains a fairly constant 8-10°C all year round, ensuring your heat supply is constant and reliable; unlike air source heat pumps, which are impacted by external fluctuating air temperatures causing higher bills when heat is most needed.


Find out more about Kensa’s ground source heat pump solutions for social housing by clicking the links below:


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