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 businesses to prosper in an economically, socially and environmentally sustainable fashion in the long-term.

This includes a focus on developing a robust and accessible procurement framework for Optimised Retrofit, and providing supplier and employment opportunities across Wales as part of the programme.

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

Each project will fall under five main themes, with a click through to further information on each specific project and leading partners. The five subheadings are:

Skills & Training

A number of mini-projects will be delivered as part of the Optimised Retrofit programme to help identify existing skills gaps within the retrofit industry, and help develop a framework for upskilling and re-training existing industry professionals.

The project will also develop training provision for young people through further education provision and industry training, and promote this as an exciting career path to those not yet to enter the industry.

Careers in Decarbonisation Magazine

Producing three Wales editions (English and Welsh language versions) highlighting to 14-18 year olds the career opportunities within Decarbonisation.

Identifying How to Address Client Skills Gaps

CEW are engaging, raising awareness and understanding of decarbonisation to a targeted audience of Welsh construction sector, SME’s and clients.

Identifying Professional Skills Gaps

RSAW are hosting three CPD sessions, led by Sero with delegates from across Wales. Themes include What is Decarbonisation, Whole Home Surveys and Pathways to Zero.


Currently one of the main barriers for improving existing homes to make them more energy efficient is cost. This applies to RSLs, private landlords as well as homeowners looking to decarbonise their own homes.

This strand of work will explore how this problem could be addressed through new and innovative finance and mortgage products, that identify the value of the work being undertaken.

Financial Tools for Decarbonisation

Building on previous work undertaken by Sero to develop a financial offer for home owners (residents or landlords) to repay capital decarbonisation costs through energy bill savings.

Value Differentials for Decarbonisation

Developing deeper understanding of the barriers to retrofit in PRS (financial, logistical and motivational); and to take lessons from the outcomes of other strands of the optimised retrofit project (OR) to analyse ways in which the identified barrier can be released.

Community & Occupancy

Housing is responsible for 29% of UK carbon emissions. The profile of the climate emergency and public awareness of the need to be more sustainable in the way we live day-to-day is continuing to increase.

Also, as well as saving the planet, by improving our homes we can save money on heating bills and improve our comfort, health and well-being.

Much of the Optimised Retrofit technology is relatively new to people, so increasing community understanding around home energy and the impact on our carbon footprint will be key to helping deliver widespread decarbonisation of our housing stock.

Blaenau Gwent Citizens Assembly

Engaging with citizens from Blaenau Gwent grappling with the question: ‘What should we do in Blaenau Gwent to tackle the climate crisis in a way that is fair and improves living standards for everyone’.

Post Occupancy Assessment Surveys

Understanding the potential financial, social and health benefits of retrofitting homes. To understand residents attitudes & behaviours towards energy, changes in these behaviours over time and reasons for wanting/not wanting retrofit.

Are you Comfortable? Quality of Life Assessments

Capturing occupant data at pre-retrofit and post retrofit stages on: physical functioning and health, role limitations due to physical health, emotional health and wellbeing, role limitations due to emotional health, physical energy and fatigue, social functioning, pain, and general health.

Comparing findings with monitored environmental condition data from the IES. Reporting on occupant comfort and health and how dwelling conditions pre/post retrofit may affect these variables, and whether partners may need to consider refinement to retrofit measures.

Retrofit Measure Studies & Analysis

Measuring qualitatively and quantitatively the fabric of dwellings to identify any potential air leakage pathways which could impact upon thermal comfort (occupant physical health), sound penetration (occupant mental wellbeing), paths for fire, smoke, or toxic gas movement (occupant safety and physical wellbeing).

Reporting on findings and how occupant’s health could be affected, and whether partners may need to consider refinement to retrofit measures.


A number of strands of research will be undertaken as part of the overall Optimised Retrofit project, to ensure that potential learning from the project is maximised and that long-term foundational economy benefits are established.

A Standard for Measuring Energy Savings

Developing a recognised method for measuring the outcomes of home energy upgrades that can be referenced by the BSI Building Performance Evaluation standard currently under development, by PAS2035 and may itself be the subject of a formal standard.

Forecasting Grid Decarbonisation to 2050

Producing a half-hourly UK grid carbon intensity dataset from 2021 to 2050, for use in energy and carbon modelling scenarios.

Semantic Conceptualisation of Optimised Retrofits & Automated Data Collection

Developing a semantic conceptualisation of the Sero vision of retrofitting of a domestic buildings. Secondly, investigating how semantic rules can be used to automate the decision making regarding the selection of retrofitting interventions based on the semantic model of the property that has been constructed.

Marketplace Certification

Creating a data marketplace enabling a number of different suppliers to participate in a “Pathway to Zero” carbon marketplace.

Retrofit Case Studies & Analysis

Developing a series of case studies exploring retrofit of pre-1919 stock, with a view to developing learning that will apply to both PRS and private homeowners. Critiquing the Whole Home Survey and retrofit pathway generated by ORP tools. Looking more broadly at ways to use retrofit to improve dwelling quality.


THERMOS (Thermochemical heat energy recovery and modelling opportunities for storage), targeting the decarbonisation of domestic hot water and space heating provision by modelling the use of low carbon thermal technologies, development and modelling of thermal storage mediums, providing assessment of economic and environmental benefit and finally consulting with specifiers, installers and end users to ensure that the proposed solutions would provide an acceptable system covering the requirements of the general public.

Procurement & SMEs

Decarbonisation Procurement Framework

Developing a procurement piece that allows for purchasers to retain high levels of control over selection of materials and installers, cost and quality, whilst also maximising the opportunities for SME’s to participate and develop.

Engaging SMEs with the Decarbonisation Procurement

Engaging, recruiting and training the network of SMEs required to deliver Optimised Retrofit. Identifying and overcoming barriers to engagement and offering mentoring, alliances and both technical and operational support.

Building Passports & Third Party Interfaces

Digital Map of Future Decarbonisation

Analysing survey and Pathways to Zero data to assess the future needs for energy efficient technology installation requirements and associated planning.

Welsh Gov HSAR API Interface

Working closely with Welsh Government to integrate the data captured from the Whole Home Surveys and Pathways to Zero into the Housing and Stock Analytical Resource (HSAR), provided the relevant consents from the RSLs are provided.