Cornwall Council: Whole House Retrofit Innovation Project

Cornwall is working towards an ambitious target of being Net Zero by 2030 and are finding ways of cutting their carbon footprint, while improving the quality of life of their citizens. Making energy efficiency improvements to existing properties is a key part of their response to tackling the climate emergency. But it also shows commitment to social justice by helping to reduce fuel poverty.


The challenge

Cornwall’s existing homes make up 22 per cent of its carbon footprint, with over 97,000 solid wall properties and 133,000 homes off-gas. The Council recognise the need to substantially reduce these emissions, while reducing energy bills for Cornish residents on low incomes and vulnerable to the effects of living in cold homes.

The Council views their commitment to tackling climate change as symbiotic with meeting the needs of their most vulnerable residents. The whole-house retrofitting model cuts emissions and lowers heating bills for residents.

The Department for Business, Energy and Industrial Strategy (BEIS) has provided £1.051 million of funding, with another £2.28 million coming from Cornwall Council and £880,000 from SSE.

The solution

The Whole House Retrofit Innovation (WHRI) project – a £4.2 million pilot scheme that will see radical improvements fitted to council owned homes – will significantly reduce the properties’ emissions, heat loss and running costs.

The pilot will initially make 83 of the poorest performing homes warmer and greener through improvements such as loft, external walls and under floor insulations, solar panels, single-room ventilation and ground source heating.

By adopting a fabric-first approach, the WHRI project aims to achieve an in-project cost saving of between 5-20 per cent, while delivering a post-retrofit energy intensity of 30 kWh/M² (often referred to as the ‘Paris Proof’ target).

Cornwall Council was one of three local authorities to secure BEIS funding for this project. In Summer 2019, the Government published a summary of responses to the call for evidence on building a market for energy which laid out the barriers to energy efficiency uptake in the UK. Important amongst these was the deterrent posed by the high upfront cost of significant improvements in energy efficiency. The aim of this programme is to demonstrate how much more cost-effective the whole-house approach to retrofitting is, thanks to economies of scale and scope.

Work on the first properties was due to begin in January 2021 but was inevitably delayed because of the COVID-19 lockdown.

The impact

The homes will benefit from radical improvements such as insulation to lofts, external walls and under floors; solar panels; single room ventilation and heat recovery and ground source heating, reducing their carbon emissions by up to 80 per cent and heating costs by up to 50 per cent.

The carbon-reducing programme aims to be a cost-effective model to improve the energy efficiency of Cornwall’s existing homes – exploring the benefits of whole-house retrofitting alongside the costs of replacing older houses with new green builds.

The model has been developed to be replicable. The Council want to see it being offered to other social landlords, owner-occupiers and the private rented sector across Cornwall. The hope is that it can then be deployed by other rural communities with similar housing stock and climate conditions, across the UK.

Previously, whole-house retrofit measures have not been delivered at scale. BEIS has committed significant future investments of around £3.4bn to help provide solutions and learning for future large-scale projects. There is now a growing community of projects within Cornwall and the UK, that will gather knowledge and experience of the retrofit methods, techniques and systems being applied through this project.

This pilot will be particularly helpful in informing and shaping the country’s post COVID-19 green recovery, which will require the creation of more green industry skills and jobs.

How is the new approach being sustained?

The model has been developed to be replicable, with learnings and details on cost savings available to inform future larger scale programmes.

Lessons learned

The pilot results will help to:

  • inform the details required as part of the Council's ask of government to provide long term funding solutions for housing retrofit
  • enable the Council to demonstrate how they can retrofit their own Council homes to ensure their energy performance is fit for a carbon-neutral energy system
  • provide important learnings to develop larger-scale programmes and proposals for retrofitting 10,000 Cornwall Council homes
  • help to inform other social landlords, the private rented sector and the wider public across Cornwall.

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