Creating net-zero homes in Maldon, Essex

Maldon, Essex
by ENGIE (solution provider), GSA (architect) and Moat (housing provider)

The UK’s second Energiesprong pilot was delivered by ENGIE and GSA for Moat in rural Maldon,Essex, offering residents healthier and more affordable homes.

The challenge –  creating energy-saving homes within strict planning regulations

Completed in 2019, this 5-house pilot was supported by European funding from the INTERREG E=0 project. Housing provider Moat wanted to provide better homes for its tenants, as well as invest in supporting the UK’s net-zero targets.

The demonstrators were situated on one side of the road in a rural setting exposed to the elements, with the coast just a short walk away.  This meant that, despite low D EPC ratings, these households faced with high heating bills and associated challenges of fuel poverty.

The local planning office required that the street scene remain unchanged so, apart from the addition of solar, original looks needed to be preserved.

Homes before (left) and after (right)

The solution – an offsite modular approach to whole house refurbishment


With an ambitious target to reduce the level of carbon dioxide per house by 3.2 tonnes per year, as well as create warmer, more desirable homes for tenants, the Energiesprong model was adopted.


The homes were fitted with solar panels, energy-efficient roofs and doors, triple glazed windows, insulated shell and floors to keep the homes warm and reduce noise from the road, air-source heat pumps, battery storage and improved ventilation. This included an innovative offsite approach for the insulated façade and roofing system to speed up installation.

To keep the looks the same, solution provider ENGIE opted for acrylic brick-effect external insulation panels, which were colour-matched to the brickwork they cover. ENGIE also replaced the dormer windows to the front (Velux to the rear) which are highly insulated, triple glazed, and let in plenty of light.

Tenant engagement was also key to the project with ENGIE consulting with residents throughout the process, including weekly progress meetings. ENGIE also helped residents get the most from their new homes with bespoke training and a residents’ manual that outlined how to use the new technologies installed.


The impact – cheaper-to-run, award-winning homes, guaranteed for 30 years

After retrofit, homes were designed to be considerably more affordable to keep warm in winter, with a guaranteed temperature throughout the house. The homes look and feel better with reduced mould, damp and condensation – as well as new windows, doors and facades.

This scheme has won a number of awards, including:

  • Ashden Award - UK Sustainable Buildings - Winner
  • National Energy Efficiency Awards - Winner
  • Building Innovation Awards - Most Innovative Building Project - Finalist
  • Housing Essex - Innovation Award - Winner.

Full list of measures

  • Roof and wall panels – Mauer
  • Controls and energy module – Factory Zero
  • Heat pump – Mitsubishi
  • Battery – Moixa
  • Monitoring - Enervalis
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