The collaboration of 68 partners, including 26 social housing providers, has been awarded more than £7m in funding by Welsh Government through the Optimised Retrofit Programme that was introduced this year as part of the Innovative Housing Programme.

What does Optimised Retrofit mean?

Optimised Retrofit is the retrofit of an existing home which provides effective, practical pathways to take that home to its lowest achievable carbon footprint. This is achieved through a combination of building fabric improvements, low and zero-carbon technologies (such as solar panels, battery storage and heat pumps), and intelligent ongoing operational controls.

The approach, referred to as Pathways to Zero, is designed to support incremental home upgrades over multiple steps, in a coordinated way. The scheme enables delivery of a more comprehensive level of genuine zero carbon, typically for less cost, by supporting and aligning with the decarbonisation of the energy grids that will take place over the coming decades.

Optimised Retrofit supports each unique home to be assessed in significant detail, with all technical viable measures considered in all appropriate sequences. Accepting the paramount importance of the residents, these measures include how to deliver the ongoing real performance of the home to achieve comfort without complexity.

Project aims and outcomes

The primary objective of Optimised Retrofit is to leave a legacy to help decarbonise homes in Wales and beyond. The project partners between them currently manage more than half of the social homes in Wales (around 123,000 of the total 237,000), and all RSLs in Wales will have access to the processes, training, frameworks and tools that are built as part of Optimised Retrofit.

A sustainable business model will be developed that sets out the costs of operating the core digital tools, framework, and relevant foundational economy elements, as well as ongoing dissemination and development activities.

Optimised Retrofit is the means of delivering a clear mechanism for the homes in Wales to take meaningful, coordinated steps to decarbonise using a structured, technically robust methodology, whilst remaining as affordable and pragmatic as possible.

Project Overview

The project has three main pillars of work:

Pathfinder Retrofits

The pathfinders, or pathfinder homes, are the pilot residential refurbishment projects being undertaken by project partners that help to develop the Optimised Retrofit tools and mechanics.

Across the project, partners will decarbonise more than 1,370 Pathfinder homes across Wales, which will each be provided with a detailed pathway to achieve Zero Carbon based on retrofit measures and grid decarbonisation.

The pathfinder programme will use a combination of building fabric improvements, low and zero-carbon technologies (such as solar panels, battery storage and heat pumps), and intelligent ongoing operational controls, to take each home to its lowest achievable carbon footprint.

The project will see a wide range of types of homes being retrofitted, to ensure the digital tools being developed are effective in tackling the diverse range of property types found across Wales.

Digital Tools

The Optimised Retrofit collaboration will use the pathfinder homes to refine a range of digital tools that enable each home to be easily and quickly surveyed, and Pathways to Zero carbon identified. This is specific to each home and is undertaken in any number of coordinated steps over any period of time to take that home to its lowest achievable carbon footprint. It includes forecasting the year that each home will achieve zero carbon, based on the recommended improvements, as the grid becomes greener.

Following the completion of the Optimised Retrofit programme in summer 2021, these digital tools will then be made available to Welsh social housing providers, academia, government, and private homeowners. This will enable the long-term delivery of a legacy of tools, skills, frameworks, and evidence, to allow other projects to follow suit and enable the decarbonisation of Wales’ homes to quickly gain scale and pace.

Foundational Economy

The Foundational Economy is an approach taken by the Welsh Government to ensure their funding improves the way the local economy works in Wales by developing the growth to vital services and goods.

The Optimised Retrofit collaboration is designed to help deliver decarbonisations through the Welsh economy and to form an environment that will enable small scale Welsh business to prosper, both in Wales and beyond, in a long term economically, socially and environmentally sustainable fashion.

As well as social housing providers, this large-scale collaboration of partners includes a range of research, innovation, academic, technology, energy, and industry organisations from across the UK. As well as providing supplier and employment opportunities across Wales, these will lead supporting activities such as cutting-edge research, training, and upskilling, and establishing frameworks for the retrofit industry, to enable the Welsh economy to become a true leader in decarbonisation.

The Optimised Retrofit Partners

Contact Us

For all general enquiries or if you would like to receive updates on the Optimised Retrofit project, please get in touch.


For all press and media enquiries please contact Grasshopper Communications:

Clare Jones:, 07793 382021

Damian Kerlin: