What is PAS 2035?

PAS 2035 is the new over-arching document in the retrofit standards framework introduced following the recommendations of the Each Home Counts review.  PAS 2035 essentially provides a specification for the energy retrofit of domestic buildings, and details best practice guidance for domestic retrofit projects.


It is evident that significant improvements need to be made within the energy efficiency of the UK’s building stock, if the country is to meet its global carbon commitments. In 2015 the government commissioned the Each Home Counts review to identify and tackle the high level of failure present in domestic retrofit, and to determine a better process for the retrofit of energy efficiency and renewable energy measures. PAS 2035 (PAS 2035:2019 Specification for the energy retrofit of domestic buildings) was introduced as a result of this review, with the backing of industry and the government department for Business Energy and Industrial Strategy (BEIS).

Following a transitionary period the government has proposed to make compliance with PAS 2035 mandatory for all public funded projects which would include ECO funded retrofit projects (see below).

How is PAS 2035 different?

This PAS embraces quality retrofit work eliminating problems associated with defects, shallow retrofit, accountability, poor design and performance gap. PAS 2035 delivers a whole building approach to the retrofit process, considering the home, environment, occupancy and the householders' improvement objectives when determining the most suitable measures to install. This eliminates the issue of retrofit work being considered in isolation which can unintentionally damage the overall building performance.

Moreover, five new retrofit roles have also been introduced within the PAS 2035 process, with clear responsibilities and accountabilities established to ensure that individuals deliver quality throughout. Elmhurst currently run training and schemes for two of these new roles, including the Retrofit Assessor and Retrofit Coordinator.

PAS 2035 and TrustMark

TrustMark Logo

TrustMark has been established as the new quality mark within the retrofit standards framework. This TrustMark is supported by an Industry Code of Conduct, a Consumer Charter and a framework of technical standards for retrofit. Users of the TrustMark Government endorsed quality scheme will be required to comply with PAS 2035 when undertaking any domestic retrofit work. Those who hold the TrustMark can demonstrate to consumers that they have the skills and knowledge to deliver the best practice standards and trading practices in the sector.

Retrofit Assessors

Retrofit Assessors are trained to undertake a retrofit assessment for dwellings in accordance with PAS 2035. The activities completed within the retrofit assessment include the production of an RdSAP assessment, a detailed floor plan, a condition report and an occupancy assessment.

The data collected from these sources is used by the Retrofit Coordinator to formulate a Medium-Term Improvement Plan. Accredited DEAs are well placed to become qualified Retrofit Assessors due to their extensive knowledge and experience with RdSAP methodology and assessment of existing dwellings.


Retrofit Coordinators

Retrofit Coordinators are required for all domestic retrofit projects in order to comply with PAS 2035. The Retrofit Coordinator occupies a vital project management role within the retrofit process and are needed to protect both the interest of clients and the public. They are responsible for overseeing a domestic retrofit project from inception to completion, and will liaise with building owners, and other retrofit project stakeholders in order to ensure effective project management.

A Retrofit Coordinator can prepare a Medium-Term Improvement Plan using data from retrofit assessments, to provide a scope for improvement over a 20-30 year period.


Elmhurst and PAS 2035

Elmhurst Energy operates a TrustMark approved Retrofit Assessor and Retrofit Coordinator scheme in accordance with PAS 2035. Members of these schemes can undertake work within domestic retrofit projects as TrustMark holders, and will be required to comply with the new standards. In addition to these schemes, Elmhurst can also provide relevant training for individuals who want to become qualified as either a Retrofit Assessor or Retrofit Coordinator. Further information is available by clicking below.

PAS 2035 and ECO3

Since the 1st July 2021, the Energy Company Obligation (ECO) scheme has been administered by TrustMark and has introduced a requirement for relevant work and any energy related improvements to be undertaken by TrustMark registered businesses.

In light of these changes, all ECO funded retrofit projects must now be overseen by a TrustMark approved Retrofit Coordinator, who will work with other TrustMark approved retrofit professionals (such as the Retrofit Assessor and Retrofit Installer).

All retrofit professionals involved will need to adhere to the technical standards outlined within PAS 2035:2019 and PAS 2030:2019.

In need of a Retrofit professional for ECO?

Elmhurst has a number of TrustMark approved Retrofit members which can be found on our public ‘search for assessor’ facility.

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