Supply Chain Advice Pack: Introduction to PAS 2035

Overview

PAS 2035:2023 (Publicly Available Specification) ensures high quality, compliant installation of energy efficiency measures in existing homes, with the aim of advancing sustainability and overall performance of the nation’s homes.

To ensure large scale retrofit meets the intended outcomes of the works, it is recommended that retrofit installation work should comply with PAS 2035; 2019(currently) or PAS 2035; 2023 (from March 2025).

Unlike PAS 2030 which is the accreditation for installer organisations, PAS 2035 is not  a certification that an organisation achieves, it is a standards framework that must be adhered to. It is not possible to be “accredited “to PAS2035, instead retrofit services that are provided must that comply to the framework as part of the project. The key outcome is a final lodgement into the TrustMark Data Warehouse by suitably qualified personnel, for example. a TrustMark-registered Retrofit Coordinator

What are the key roles for PAS 2035 compliance?

PAS 2035 requires a number of key roles to be included within the project. Each role has a specific responsibility, and their activity must documented as part of the lodgement submission. These key roles are:

• Retrofit Assessor – asses the dwelling in advance of works to capture up-to date characteristics, occupancy and condition information.
• Retrofit Designer – develops an appropriate retrofit design for the property.
• Retrofit Coordinator – oversees the entire retrofit process and is responsible for assurance that best practice is followed and enacted.
• Retrofit Evaluator – reviews the outcomes of the projects and acts a quality assurance on the role of the Retrofit Coordinator.

Each role must be performed by a suitably qualified professional with relevant experience for their part of the process. The complexity and challenges that the project is likely to face has an impact on the skills required. Deeper and more technical retrofit projects require more in-depth expertise at each stage of the process.

A construction professional (for example, a surveyor or architect) who has trained as a Retrofit Coordinator is able to deliver each of the roles should that be required; however, they must evidence relevant qualifications for higher risk projects.

Further detail on the role requirements can be found in Annex A of PAS2035;2023

What is the PAS 2035 process?

The PAS 2035 process is grounded in a risk assessment that determines the level of associated risk to completing a project, this is done at project commencement and informs the delivery requirements. This is done as a desktop exercise against the proposed project characteristics.

A retrofit assessment is then completed to capture the latest up-to-date site information, including occupancy and ventilation requirements.

A retrofit design is then produced from the assessment including the interfaces between the measures proposed. The Retrofit Coordinator has oversight of the process to ensure it remains compliant.

Once the installation works have started, site visits are undertaken during and after the works, to maintain compliance with PAS 2030. Once works are complete and upon receipt of the required documentation and certifications a lodgement of the project and measures is made, into Trustmark’s data warehouse, by the Retrofit Coordinator. The lodgement includes any guarantees associated with the works.

This process provides assurance that the work has been completed to high level of technical skill and a long-term insurance backed guarantee, giving the owner of the home peace of mind that the works have been completed correctly.

A full outline of the process can be found in the PAS 2035; 2023 specification.

What are the benefits of PAS 2035?

• It provides accountability for the retrofit process, which is independent to the installer, to maintain standards and quality of retrofit installations.
• It considers a building holistically as a set of measures and interfaces that interact as a whole-house system, thereby any improvements aim to avoid unintended consequences of the works over the long term.
• It creates standardisation of technical approaches, where possible.
• Regulated training course on the technologies you want to install before having a first installation independently assessed, post completion.