Domestic retrofitting - the upgrading of existing homes to improve energy efficiency, cut carbon emissions, and enhance comfort, health, and resilience - plays a critical role in supporting Wales’ pathway to net zero by 2050. It also offers an opportunity to reshape how the economy functions and deliver wider benefits, such as improving housing quality, reducing fuel poverty, creating skilled jobs and supporting long-term economic resilience.
Retrofit, however, faces persistent barriers, including high upfront costs, disruption to households, skill shortages and complex grant and planning processes. Overcoming these challenges requires targeted, large-scale investment to de-risk the market, consolidate demand, create economies of scale and drive innovation and upskilling. Local authorities can play a convening role by establishing trusted delivery models and coordinating area-based programmes that enable shared solutions such as clean heat networks. In Wales, where housing is diverse and often inefficient, well-timed, building-specific interventions are essential.
Cardiff Council is seeking to upscale domestic retrofit across all tenures - social housing, private rental and owner occupied - aligned with Welsh Government objectives and complementing its ‘One Planet Cardiff Strategy’ to achieve a carbon neutral city. To support this work, we were asked to review existing evidence and best practices to explore three questions:
- How can targeted, large-scale investment stimulate the development of a wider domestic retrofit market?
- How have similar programmes been implemented elsewhere, and what lessons can be drawn for Cardiff?
- To what extent does this programme align with Welsh Government objectives, and how could a local authority-led initiative complement national efforts?
We drew on five case studies: Kirkless Warm Zone, Warm Wales (Arbed 1), Green Homes Wales, Tŷ Gwyrddai, and the US Better Buildings Neighborhood Program. These examples highlight the importance of trusted local delivery partners, blended and flexible funding, accessible finance, and sustained investment in skills and local supply chains. These elements are central to delivering retrofit at scale and ensuring a just transition.
Aligning local retrofit strategies with Welsh Government policy is important to ensure delivery does not become fragmented and less cost effective. Key recommendations include adopting Optimised Retrofit Programme (ORP) standards across tenures; integrating retrofit with Local Area Energy Plans and heat zoning; prioritising fuel-poor households; applying WHQS 2023 standards; embedding skills development; and blending funding sources. Ensuring sufficient capacity, skills and adequate resourcing will be important to delivering domestic retrofitting at scale. From this review of the evidence, we identify three implications for policy:
- Stronger alignment between national and local policy alongside greater clarity and direction to provide certainty for households, supply chains and investors.
- Finance must be linked to projects in ways that make retrofit both investable while affordable and accessible across tenures.
- Long-term planning, cross-sector alignment, and consistent standards are essential to ensure that retrofit delivers both climate and social objectives.
