Supply Chain Advice Pack: Understanding retrofit scheme standards

Overview

To support the delivery of large-scale domestic retrofit, schemes such as the Energy Company Obligation (ECO4) require activity to comply with specific standards.

Retrofit installation work must comply with PAS 2030; 2019+A1 2022(currently) or PAS 2030; 2023 (from March 2025) or MCS, for low carbon and renewable energy technologies. 

In addition, the above schemes all require non-installation retrofit work, incorporating Retrofit Assessment, Retrofit Design, Retrofit Coordination (project management), handover and Retrofit Evaluation, to comply with PAS 2035; 2019+A1 2022(currently) or PAS 2035; 2023 (from March 2025).

If you are working in the retrofit supply chain, to access and deliver installation work under PAS requirements, you must hold appropriate certification through a TrustMark registered certification body for the measures or technologies that you aim to install.

Why are standards needed?

Following the Each Home Counts review, it was identified that there was a need within the housing industry to manage quality of works when improving the energy efficiency of buildings. After decades of retrofit activity there had been significant number of unintended consequences following improvement works that have left a lasting impact on residents’ homes.

Some high-profile cases, such as the Fishwick retrofit project, and cavity wall installations from the Green Deal, created severe issues for the residents, negatively impacting their lives and causing damage within the homes. and cavity wall installations from the Green Deal, created severe issues for the residents, negatively impacting their lives and causing damage within the homes.

Record investment into energy efficiency of our home to meet net zero targets poses a significant risk if methods and solutions are not appropriately designed, installed, and maintained. We must consider the building as a whole system which should be carefully maintained.

The PAS 2030 & 2035 framework have been introduced to provide a domestic retrofit guidance and specification process to retrofit our homes and to drive best practice and accountability for quality of the works.

What role do each of the standards have?

There are three key standards that are driving the level of change that is required to deliver net zero ambitions. The three standards below enable long term guarantees to be secured for the completed works, which provides assurance and enables defined outcomes to be achieved.

PAS 2035

This is the British standard for retrofitting existing dwellings, and it outlines how retrofit projects should be managed and delivered. PAS 2035 is primarily for the owners and occupants of dwellings which require retrofit work. Its purpose is to avoid delivery of poor quality retrofit which risks causing harm to occupants and damage to the building.

PAS 2030

Is the specification for the installation of retrofit measures into existing dwellings. PAS 2030 is for installers of Energy Efficiency Measures (EEMs) and its purpose is to set out the requirements for delivering good quality installations which perform as specified.

Microgeneration Certification Scheme (MCS)

An industry-led quality assurance scheme, which demonstrates the quality and reliability of approved products and installation companies installing low carbon or renewable energy technologies. MCS works with industry to set, define, and maintain the standards for contractors and their installations.

What does PAS stand for?

A PAS (Publicly Available Specification) is a fast-track standardisation document – the result of an expert consulting service from the British Standards Institute (BSI).

It defines good practice standards for a product, service, or process. It is developed by a steering group of stakeholders, selected from relevant fields, and led by BSI. It is a powerful way to establish the integrity of a new innovation or approach.

The primary objective for PAS 2035/2030 remains the provision of a robust, uniformly applicable EEM installation process that can assist retrofit Installers that comply with its requirements in full to demonstrate that their installation processes can provide installation to specification and in accordance with the client’s expectations.