Retrofit Assessor

Improving your property's energy efficiency

Retrofit means making modifications to bring your property up to date to improve energy efficiency.
The UK Government is committed to bring all greenhouse gas emissions to net zero by 2050. By making energy efficiency upgrades to your home you will not only future-proof your property but also reduce running costs.


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ESL is an accredited Retrofit Assessor and is a TrustMark registered business which is the Government endorsed quality scheme. 

If you own an older house (or one which has an Energy Performance Certificate rating between D and G) and you plan to make energy efficiency improvements you may choose our services and expertise.

We will carry out a full house survey which is part of the retrofit process. The full house survey will identify areas which require energy efficiency improvements. This will reduce your fuel bills and carbon emissions. You can do this through the Green Homes Grant.


The Green Homes Grant

The Government’s (£2bn) Green Homes Grant was launched by Rishi Sunak, Chancellor of the Exchequer, in July 2020. This aim of this initiative was to support the economy through the Covid-19 pandemic. The scheme which was due to end on 31 March 2021, has now been extended to 31 March 2022.

The Scheme enabled homeowners to apply for a voucher that can contribute towards the cost of specified energy-saving home improvements. In general, the scheme would entitle home owners to a voucher (worth up to £5,000). This must cover no more than two-thirds of the cost of the efficiency improvement works. If homeowners receive certain State Benefits, vouchers can be for the total cost of works completed up to £10,000.

You are currently eligible for energy efficiency improvement grant works if you have already applied for a grant prior to 31 March 2021 or if you already hold a voucher or have received confirmation of the voucher.  Please don’t waste your voucher, and use it before the revised deadline of 31 March 2022* (correct at June 2021).

The scheme is now closed for new applications.


Types of Retrofit Improvements

Primary Measures include Insulation and low carbon heating

Once the Primary Measure(s) improvements have been completed, Secondary Measures may be addressed.

Secondary Measures include windows and doors; heating controls and tank insulation

The energy-saving works must be completed by TrustMark registered companies.

  • A Retrofit Advisor will provide advice and guidance to you. A qualified Retrofit Assessor will then carry out a full-house survey of your home (this is where ESL works with you) and submit this to the Retrofit Co-ordinator who oversees the project and works with a Retrofit Designer, Retrofit Installer and ultimately an Retrofit Evaluator.

Yes, it does sound quite complicated, but this is a team-led programme of work. Its aim is to provide you with the all the benefits of future proofing your home through making energy savings and energy costs. With effect from 1 July 2021 all ECO3* work must be overseen by a TrustMark registered Retrofit Coordinator.

What is ECO3?*The Energy Company Obligation (ECO3) is a government scheme that delivers energy efficiency and heating measures to homes in Great Britain. The focus of the scheme is to support low income, vulnerable and fuel poor households.

What is PAS 2035?

PAS 2035 is a set of standards or ‘rules’ that TrustMark approved Retrofit professionals must follow.

This covers everything from defining roles within the process i.e. Retrofit Assessors, Retrofit Coordinators, and Retrofit Designers, to creating processes for different categories of buildings, and, if needs be, redress.

Source: Elmhurst Energy: July 2021


About the Standard

All energy performance upgrades must fall within the framework of PAS 2030 and PAS 2035 and covers the installation, commissioning and handover of retrofit projects. PAS 2035 was developed to support the PAS 2030 installation standard and became mandatory from January 2021. The retrofit process will comply with all these standards.



  • TrustMark is the Government Endorsed Quality Scheme covering work a consumer chooses to have carried out in or around their home. When a consumer uses a TrustMark Registered Business, they know they are engaging an organisation that has been thoroughly vetted to meet required standards and has made a considerable commitment to good customer service, technical competence and trading practices.
  • By ensuring all Registered Business adhere to and maintain these standards through our expert network of Scheme Providers TrustMark gives consumers increased confidence and choice.  Additionally, in the event that a problem does arise, TrustMark offers a range of remedies to give further protection to consumers.

And to end…. back to the beginning

In 2016 the Government commissioned an independent report written by Dr Peter Bonfield, former Chief Executive of the Building Research Establishment (BRE) which is a centre of building science in the United Kingdom. The Each Home Counts report formed the corner stone for all progress made towards driving energy efficiency improvements.