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Last edited 24 Apr 2025

Retrofit projects and roles

[edit] Introduction and context of retrofit

There is a wide variety of work that may be carried out on existing buildings; ranging from simple alterations to full extensions, fit-out to full refurbishment, remediation to renovation or repurposing and restoration through to deconstruction to demolition. There is increasing pressure to retain existing structures wherever possible, in relation to growing interest in a more circular economy and to reduce the embodied carbon impact of buildings.

Retrofit is a term used to describe works to existing buildings, often with a focus on Energy Efficiency Measures (EEM) products, systems, and materials to improve 'energy efficiency and other outcomes' (PAS 2035:2023). Other outcomes might include improved comfort, air quality, health, resilience, and appearance.

Retrofit is also used with reference to post-completion fire safety measures, especially following the Grenfell Tower tragedy (which was associated with a retrofit cladding scheme). Retrofit is generally used in relation to the installation of any new building systems, which might include heating, cooling, MVHRor fire systems, but also the fabric of a building, such as cavity insulation, loft insulation, thermal render, thermal plaster, rainscreen systems, insulated cladding (in the case of Grenfell), double glazing, seals, etc.

Retrofitting in general may be defined as “providing something with a component or feature not fitted during manufacture or adding something that it did not have when first constructed” (Ref. Retrofit 2050: Critical challenges for urban transitions); definitions of related terms can be found in the various documents and brief descriptions below.

[edit] Retrofit related schemes

The focus on energy comes from knowledge that approximately 30% of the UK’s carbon emissions come from buildings, particularly homes. The UK Green Building Council estimates that some 29 million homes will need to be retrofitted before 2050, and figures by Trustmark from November 2024 indicate that some 225k retrofit assessments have already been carried out in the UK. Some indicative figures note that up to £118bn might be needed over the next 5 years to retrofit UK homes to achieve higher energy efficiency standards by 2030 (see updating MEES for privately rented homes in England and Wales by 2030).

Because of the scale of retrofit needed across the UK, there are a variety of government-initiated schemes, some ongoing, some closed and others under discussion.

Open

Boiler Upgrade Scheme - Grant to cover part cost of replacing a fossil fuel heating system with an alternative.
Energy Company Obligation (ECO): Phase 4
Great British Insulation Scheme (GBIS)

Closed

Home Upgrade Grant phase 2 - LA performance and heating system funding for off gas grid homes in England.
Sustainable Warmth Competition - LA energy saving and LC heating fund for in low-income households.
Social Housing Decarbonisation Fund (SHDF) Wave 2.1- Social homes energy performance funding.
Social Housing Decarbonisation Fund (SHDF) Wave 2.2 - Social homes energy performance funding.

Because of the complexity of ensuring retrofit projects are carried out correctly, efficiently and effectively, especially with regards to any funding schemes, different projects and the roles that have developed are increasingly defined within standards along with competencies to be evidenced by certain qualifications. It is generally a requirement of the government related schemes that such projects are carried out to the correct and up to date standards and by persons with the appropriate qualifications.

[edit] Retrofit standards

A retrofit design, as defined by the PAS 2035:2023 standard, is described as a 'package of information prepared by a retrofit designer that determines the unique combination of EEM systems, products, and materials to be installed in a building, as well as their interrelationships, in order to achieve specified energy efficiency and other outcomes for that building.'

PAS 2035 is one of the key published documents available on the subject of retrofit:

The 'Residential retrofit standard: RICS Professional Standard UK' published by RICS in March 2024
PAS 2030 - Installation of Energy Efficiency Measures in Existing Dwellings published by BSi in 2023
PAS 2038:2021 Retrofitting non-domestic buildings for improved energy efficiency
PAS 2035:2023 'Retrofitting dwellings for improved energy efficiency – Specification and guidance first published by BSi in 2019, then 2021 and most recently in 2023
BS 40104 Assessment of dwellings for retrofit (in preparation see below)

Furthermore, the British Standards Institute are developing a standard which aims to provide standardisation of the method of retrofit assessment described in PAS 2035. This assessment is completed as part of the process that records vital evidence for the stakeholders in the process. The standard will provide requirements for the level of expertise needed for the role of the retrofit assessor and is being developed by the CB/401 - Retrofitting Energy Efficiency Measures Committee, currently referred to as BS 40104 Assessment of Dwellings for Retrofit.

[edit] Retrofit related roles

[edit] Post-retrofit inspector

A post-retrofit inspector is an ' appropriately qualified and competent professional with responsibility for carrying out the evaluation of the completed project.' As described in the RICS 'Residential retrofit standard: RICS Professional Standard UK', published as a 1st edition in March 2024, effective from 31 October 2024.

[edit] Retrofit advisor

Retrofit Advisors may be the first point of contact for residents who are looking at a retrofit project, they may give support, advice and carry administrative tasks, possibly communicating with the assessors, coordinators, designers, installers and the client.

[edit] Retrofit assessor

The retrofit assessor has a key role in such projects, and is described by PAS 2035 simply as "person qualified to carry out a retrofit assessment". Under PAS 2030:2023 (BSi) the role is more clearly defined in annex A.1 alongside the required qualifications and level of competence. Trustmark runs a Retrofit Assessor Scheme working group to bring consistence in the expected competency of such assessors, which are also outlined in the PEPA Retrofit Assessor Scheme Requirements (2025 Edition)

The RICS standard describes a retrofit assessor as 'The appropriately qualified and competent professional with responsibility for carrying out the survey inspection, design and/or other technical assessment of the property chosen for retrofit, e.g. an associate, member or fellow of RICS.'

[edit] Retrofit coordinator

The RICS standard describes a retrofit coordinator as an 'appropriately qualified and competent professional with responsibility for end-to-end coordination of a residential retrofit project, e.g. the lead professional, project manager or similar.'

A retrofit coordinator might:

Provide project management and client assistance with regard to planning, organising and management.
Provide consultants and contractors with informed advice and support.
Provide clients with assurance that project risks are being effectively managed and quality is being maintained.
Identify and provide solutions for possible risks to the retrofit process.
Undertake post-occupancy evaluation to determine overall performance.

[edit] Retrofit contract administrator

The RICS 'Residential retrofit standard: RICS Professional Standard UK', describes a retrofit contract administrator as 'The appropriately qualified and competent professional with responsibility for monitoring the construction and/or fitting of the retrofit installation(s) and associated building works, such as repairs prior to installation of EEMs at the property chosen for retrofit, e.g. an RICS member, engineer, architect or similar.'

[edit] Retrofit designer

A retrofit designer is described by RICS in their ' 'Residential retrofit standard: RICS Professional Standard UK', published in March 2024 as 'The appropriately qualified and competent professional with responsibility for design and specification of a retrofit project, e.g. an architect, chartered building surveyor or similar.'

Retrofit design in PAS 2035:2023 'Retrofitting dwellings for improved energy efficiency – Specification and guidance' is described as a 'package of information prepared by a Retrofit Designer that determines the unique combination of EEM systems, products, and materials to be installed in a building, as well as their interrelationships, in order to achieve specified energy efficiency and other outcomes for that building'

Retrofit designers are most likely to; lead a design, co-ordinate information from various packages and ensure theses are well integrated and assume responsibility for the overall design, and in particular any measures that are not covered by specialist design packages.

[edit] Retrofit evaluator

A retrofit evaluator in PAS 2035:2023 'Retrofitting dwellings for improved energy efficiency – Specification and guidance' is described as a 'person qualified to monitor and evaluate the effectiveness of a retrofit project and provide feedback to the client and/or the project team'. In Annex A.4 of PAS 2035:2023 a detailed breakdown of the qualifications and competencies required for a retrofit evaluator are given.

[edit] Retrofit installer

A retrofit installer is a 'person or organisation responsible for undertaking and supervising the physical placement of an Energy Efficiency Measure (EEM) in an existing building, together with any other associated repairs and other works, usually a building contractor.' As described in the RICS 'Residential retrofit standard: RICS Professional Standard UK, 1st edition in March 2024, effective from 31 October 2024.

PAS 2030 describes this role as a 'person or organisation undertaking the physical placement of one or more EEM(s) in an existing building'. It notes that a retrofit installer is usually experienced in the installation of one or more EEMs and can be registered with the relevant certification body for each of those EEMs.

[edit] Retrofit lead professional

A retrofit lead professional is defined by 'Residential retrofit standard: RICS Professional Standard UK' published by RICS in March 2024 as 'The appropriately qualified and competent professional with responsibility for end-to-end coordination of a retrofit project, e.g. a retrofit coordinator, project manager or similar.' PAS 2035:2023 'Retrofitting dwellings for improved energy efficiency – Specification and guidance most recently published in 2023 does not mention the term lead professional.

[edit] The Building Safety Act

When considering the roles described above it is important to consider the implications of these under the Building Safety Act, which requires a named Principal Designer and a named Principal Contractor.

The HSE document 'Building safety competence information for principal contractors and principal designers: Competency standard PAS 8671:2022 and Competency standard PAS 8672:2022' published in October 2022 defines a Principal Designer as: 'an individual or an organisation. They are a designer in control of the design work, and can be, for example: an architect, an engineer (structural and others), a surveyor'

It goes on to give a brief summary of competency under PAS 8671 saying: 'The Building Regulations principal designer (PD) must plan, manage monitor design work, and cooperate, coordinate and communicate to ensure the design work, if built, complies with building regulations. It is important that the principal designer is part of the design team and not a third-party without any influence over design decisions. The principal designer should be able to co-ordinate the design team. It may help the principal designer to keep a record of designers and their responsibilities across a project. A principal designer is not expected to be an expert in every design specialism, but they are expected to know enough about the building regulations to assess whether a building design will comply with all relevant regulations. principal designers should support others, for example, in being able to pass on necessary information to contractors and explain to them how to demonstrate that elements are built properly.'

[edit] Further information and support

[edit] UK National Retrofit Hub

The National Retrofit Hub is a non-profit organisation that brings together those involved in the retrofit sector to share their expertise and work together to enable a National Retrofit Strategy to be delivered. Retrofitting homes is vital for the UK to achieve its energy, fuel poverty and climate change goals.

[edit] The Retrofit Academy CIC

Is a not-for-profit Community Interest Company (CIC) focused on developing the skilled workforce needed for high-quality, large-scale domestic retrofit projects, aiming to make every home warm, healthy, and low-carbon.

[edit] BE-ST - The Scottish Built Environment Hub

An international centre of excellence supported by Scottish Government, Scottish Funding Council and Scotland’s Enterprise Agencies, bringing together key stakeholder groups; industry, academia, government & public sector, and Scotland’s citizens to accelerate the transition to zero carbon.

[edit] Optimised Retrofit Wales

The collaboration of 68 partners, including 26 social housing providers, has been awarded more than £13m in funding by Welsh Government through the Optimised Retrofit Programme that was introduced this year as part of the Innovative Housing Programme. This link provide further details.

[edit] Northern Ireland Housing Executive

In its role as the Home Energy Conservation Authority (HECA) for Northern Ireland, the Housing Executive seeks to support improvements in home energy efficiency across the entire housing stock in the region.