The responsibility for the administration of the Energy Company Obligation (ECO) technical monitoring has now moved from Ofgem to TrustMark.

Below the quality assurance monitoring document outlines our approach, including information about how we will be carrying out desktop and technical on-site audits.

Bierce Surveying Ltd will be working with us to complete our on-site technical monitoring audits.  

The TrustMark ECO4 Quality Assurance Guide outlines the following:

Roles and responsibilities of TrustMark, Bierce Surveying Ltd, the installer (TrustMark registered business), schemes, retrofit co-ordinators etc.,
Quality assurance post-installation inspection measures, 
The requirements placed on the quality assurance process, and 
The process for the outcome stage of the on-site audit.

The requirement to lodge with TrustMark will continue; from the 1st of July 2022, the lodgement fee can be found here.

TrustMark oversees the delivery of scheme providers' performance against the TrustMark Framework Operating Requirements.

To maximise compliance across ECO and the wider retrofit sector, TrustMark will engage with our scheme providers to share lodgement data and the outcomes of our 
quality assurance programme so that the scheme providers can respond accordingly.

Please find the guides below:

Quality Assurance Process - FAQs

  • TrustMark will undertake a percentage of audits across all installers submitting measures into the Data Warehouse from 1st July 2021. We have created a risk model which will ensure that any higher risk non-compliance is managed with individual action depending on wider factors on a case-by-case basis. This includes CATEGORY 1s. The link to the latest copy of the QA Guidance can be found above

  • Each case may differ, however TrustMark’s expectation, through our revised Framework Operating Requirements, is that any non-compliance raised shall be finalised within 3 months of notification.

  • Within the TrustMark Quality Assurance process there are no quarters. New measures that are no more than 2-months-old may be inspected. Further action will be taken on a case-by-case basis based on the overall compliance of the installer and retrofit coordinator. Final outcomes of our audits will be shared with Ofgem.

  • This is highlighted within the Quality Assurance Document.

  • TrustMark plan to share information with our Scheme Providers. The Data Warehouse and the need for one central point of data collection was a key outcome of the Each Home Counts Review. In addition to on-site audits, TrustMark will also focus on auditing Retrofit Coordinators (RC) . The introduction of an RC as part of the new PAS 2035:2019 framework is to introduce whole house retrofit coordination for all installations. This combined approach, plus the option that if non-compliance deems it necessary, TrustMark may ask installers to undertake mid–install inspections, at their own cost, as part of an action plan for improvement.

  • The distinction for TrustMark monitoring purposes is based upon what is/isn’t notified onto the TrustMark Data Warehouse. Within ECO, only demonstration actions and some DHS (not shared ground loop) are not notified to TrustMark.

To Participate In ECO You Need To Be TrustMark Registered


If you are already TrustMark registered


Speak with your Scheme Provider to ensure that your scope covers your PAS:2030 certification and the relevant annexes and that they have informed TrustMark. This is needed for your measures to be eligible for the ECO scheme.

To become TrustMark registered you need to register through a Scheme Provider


Being part of TrustMark comes with many benefits, full details of which can be found on our Trade Benefits page. You can find information about the requirements of our Framework Operating Requirements (Annex A and B may help your understanding), Code of Conduct and Customer Charter in our Useful Links page.

Please note: The only way to become TrustMark registered is to be inspected and approved by one of our Scheme Providers as it is not possible to join TrustMark directly.

However, we are only too happy to give advice Tel: 0333 555 1234 or  Email:


To Lodge Work In The Data Warehouse & Generate The Certificate


TrustMark Registered Businesses will have simple access to the Data Warehouse by creating an account for their TrustMark Business Portal.

If you're an ECO Installer and already use a software platform, check with your Scheme Provider. Some are seeking to integrate with the Data Warehouse to continue using the platform you are most familiar with.

To help you get started, we have created a list of FAQs, screenshots and other useful resources on our Data Warehouse Support Page.

Information about PAS:2035 can be found here