We are upgrading 50 council homes on Ross Street and Coldham’s Grove to bring them up to a net zero carbon standard.
About a third of carbon dioxide emissions in Cambridge come from homes, mainly from heating. Decarbonising homes is crucial to fulfilling our vision for the whole city to be net zero carbon by 2030. This pilot project is exploring how we can do that.
We are delivering the extensive upgrades while the tenants, who have volunteered to take part, remain in their homes. As well as reduced energy consumption and emissions, the project’s benefits include:
- improved health and wellbeing
- a consistent and comfortable indoor temperature throughout the year
- excellent ventilation and indoor air quality, with no damp or draughts
- a refreshed and attractive home in good repair
Planning permission and building regulations approval was granted in 2023. We then selected Axis as the contractor in a tender process. Work began in an empty home in May 2024, then in the occupied properties in August. We expect the work on the last homes to finish in July 2025.
When the work is done, we will monitor the homes for up to two years. The monitoring results, alongside other practical lessons from the project, will inform our approach to future upgrade works.
Energy efficiency measures
The homes were built in the 1930s and are some of our least energy efficient properties. More than half of all heat lost from them is through the uninsulated solid brick walls. About a sixth is lost through the floor and roof.
Measures to improve the homes include:
- adding insulation to the external walls, floor and roofs. This will significantly reduce heat loss in winter and heat gain in summer.
- replacing gas boilers with air-source heat pumps, which extract heat from the air to provide heating and hot water. They typically produce about three times as much energy as they use.
- installing new mechanical ventilation with heat recovery (MVHR) systems. These will replace stale, moist air with fresh, filtered air and reduce heat loss. It also reduces humidity and the risk of condensation and mould.
- installing photovoltaic (PV) solar panels to the roofs, to provide electricity for the homes. This will contribute to the running of the heat pumps and MVHR systems. It will also enable qualifying tenants to claim Smart Export Guarantee payments.
- upgrading to triple-glazed windows and composite external doors to reduce heat loss, draughts and condensation. It will also provide better insulation against external noise.
Engagement events
Regular engagement with tenants throughout the project has been important. It has allowed us to communicate the benefits and secured trust in the process.
In September 2022, we held an online seminar for interested tenants. After a presentation to introduce the project, residents could ask questions about it.
In April 2023, we hosted a drop-in event where participating tenants could meet the architects and see the design proposals. The tenants welcomed the proposals with generally positive feedback.
In April 2024, the tenants were able to meet the contractor at a second drop-in event, and ask questions about the upcoming work.
In August 2024, the contractor hosted a coffee morning for participants to ask questions and meet other people taking part.
In December 2024, we hosted a coffee morning to bring tenants together ahead of the Christmas holiday to discuss the ongoing work.
