In November 2020 we held a webinar on the top retrofitting priorities for a warm, eco-friendly home, plus information on costs, grants and other support. Here are the presentations from speakers plus other information we collected in response questions from participants.


Chris Mordaunt (B&NES Council) providing an overview on retrofitting.

Steve Barrett (Solarsense) providing the installer perspective.

Martin Evans (Local Householder) on ‘My House & Energy’.

Information & Advice

  • B&NES: Energy at Home 0800 038 5680
  • Wiltshire: Warm and Safe 0800 038 5722
  • South Gloucestershire: Warm and Well 0800 500 3076

The Centre for Sustainable Energy produces excellent advice leaflets, covering topics from heat pumps to central heating controls. They also run the Wiltshire and South Gloucestershire advice lines (above).

Heat loss surveys: These are carried out in winter and use a thermal imaging camera to show where heat is escaping from your home.  The CHEESE Community Interest Company now provides low cost heat loss surveys in B&NES, depending on pandemic restrictions. You can also find commercial companies.


Renewable Heat Incentive (RHI). This provides grant support for ground and air source heat pumps, solar thermal water heating and biomass boilers and stoves. It is paid quarterly for 7 years following installation. See details including payback calculator, requirements and application form here.  The domestic scheme will close to new applicants on 31 March 2022.

Green Homes Grant (GHG). This covers up to two thirds of the cost of qualifying energy improvements, up to a maximum of £5000. “Primary measures” are insulation (solid and cavity walls, underfloor, loft) and low carbon heat (ground and air source heat pumps, solar thermal water heating, and biomass boilers). You can’t get a grant for a secondary measure, such as upgrading windows and doors, draughtproofing and heating controls, unless you have already applied for a primary measure. See the Simple Energy website for details and application.  The government guidance is here. It closes on 31 March 2022, by when all work must be completed.

The grants can be used together for heat pumps: the amount received from the GHG will be subtracted from the RHI payments. For both schemes, work must be done by approved installers, registered either with Trustmark (which covers most building work) or the Microgeneration Certification Scheme (MCS). Both grants are open to all householders, regardless of income. Now that the scheme has been extended for a year it should be easier to find contractors.

Heat Pumps

See the BWCE heat pumps webinar in August, especially the presentation by Stuart Bell from Mitsubishi.

From 2023 gas boilers will no longer be installed in new homes.

Older Houses

While the majority of homes in B&NES, as elsewhere in UK, were built post 1945, including 69% with cavity walls, older homes are particularly hard to make energy efficient. See the following resources for guidance:

  • Warmer Bath: produced by the Bath Preservation Trust and the Centre for Sustainable Energy. 2011. Lots of practical examples.
  • Historic England: Excellent range of resources on different aspects of retrofitting historic and older buildings.
  • Energy efficiency and renewable energy guidance for listed and historic buildings. B&NES. 2013.
  • B&NES Permitted development checklist. This covers planning permission requirements. For example, solar panels may be permitted in a conservation area depending on their visibility. Other councils have similar requirements.

Breathability: This is one of the key differences between modern and older houses. Older houses are designed to allow moisture to be transmitted to the outside, where it can evaporate: they use “breathable” materials which allow this transmission. If impermeable materials (eg Celotex) are used in an older home they may trap moisture, leading to damp, mould and general deterioration. The resources above provide further information on the dangers and how to avoid them.