Torentum Court, Fleetwood, during the programme.
On a funded retrofit programme, a subcontractor’s paperwork becomes yours. A measure installed by a firm that is not certified for it cannot be lodged, and Warm Homes: Social Housing Fund projects need every measure lodged. These are the checks to run before anyone goes on site.
Certification is checked measure by measure, not company by company
The first question is not whether a subcontractor holds PAS 2030. It is which measures their certificate names. PAS 2035 requires each energy efficiency measure to be installed by an installer certified to PAS 2030 for that measure, and low carbon heat to be installed by an MCS certified installer. The Warm Homes: Social Housing Fund Wave 3 scheme guidance adds that every installer must be TrustMark registered, and that the old route for schemes deemed equivalent to MCS no longer stands: installers must be MCS certified in all cases for relevant measures.
The rule is enforced at lodgement. Under TrustMark's Framework Operating Requirements, scheme providers tell TrustMark which PAS annexes or low carbon technologies each registered business is certified for, and that data is what stops work being lodged in areas a business is not certified for. A subcontractor certified for cavity wall insulation cannot lodge your internal wall insulation, however good the install.
So ask for the certificate number, the measure or technology it names, the certification body and the expiry date, then check it at source. We publish ours the same way. Energy Giants holds PAS 2030:2023 for one measure, B5 flat roof insulation, valid to 31 August 2027, and MCS certification for solar PV and battery storage only (MCS 001, MIS 3002 and MIS 3012), valid until 22 September 2027. Other measures we install on funded programmes are delivered under the main contractor's or the programme's certification, and before we price we set out how each measure will be certified. The details are on our accreditations page.
PAS 2035 roles and lodgement need a named owner before mobilisation
Funded projects run to PAS 2035, which splits the work into roles. TrustMark lists them as Retrofit Assessor, Retrofit Designer, Installer, Retrofit Coordinator and Retrofit Evaluator, and requires the assessor, the installer and the coordinator to be TrustMark registered. Lodgement is made by the Retrofit Coordinator unless a scheme names another lodging party, and the coordinator is responsible for getting each role's outputs into the TrustMark Data Warehouse.
That makes the subcontractor a supplier of evidence as well as labour. The subcontract should say exactly what they hand the coordinator for each property, in what form and by when. The WH:SHF guidance encourages grant recipients to lodge within 20 days of completion, and to have an appropriate measure guarantee in place before upgrades start. If a subcontractor's photographs, product data or guarantee details arrive a month late, your lodgement is late too.
One more TrustMark rule belongs in the contract itself: a registered business either accepts full responsibility for work done by a subcontractor, or the subcontractor must also be TrustMark registered, and subcontractors must be identified to the consumer.
Certificate numbers, scopes, expiry dates, policies and company details are in our supplier pack. Send us the measures and we will say how each is certified.
Twelve checks before a subcontractor goes on site
Run these at tender and again at mobilisation. Anything you cannot verify yourself, ask for in writing.
| Check | Ask for | Why it matters |
|---|---|---|
| PAS 2030 scope | Certificate number, measures named, expiry date | Work outside certified measures cannot be lodged |
| MCS | A certificate naming each technology | Required for solar PV, batteries and low carbon heat on WH:SHF |
| TrustMark | Registration, checked on the register | Every installer on WH:SHF must be registered |
| PAS 2035 outputs | What they give the coordinator for each home | The coordinator cannot lodge what it does not have |
| Lodgement timing | A deadline written into the subcontract | WH:SHF encourages lodging within 20 days of completion |
| Guarantees | The guarantee for each measure and who backs it | Financial protection is lodged with the work |
| Insurance | Employer's liability, public liability and professional indemnity | A TrustMark requirement for registered businesses |
| RAMS and CDM | Site specific RAMS, inductions and supervision | Contractors must plan, manage and monitor their work |
| Vetting | DBS checks and photo ID for anyone entering homes | TrustMark expects DBS checks where staff regularly work with vulnerable people |
| Resident liaison | A named contact, access letters, a complaints route | Residents need the same answer every time |
| Capacity | Named supervisor, team size, start date | Shows whether the team exists yet |
| Evidence pack | Photographs before, during and after, and a handover file | It is the file your client and the funder will audit |
On health and safety, the HSE's guidance on contractor duties under CDM 2015 applies to subcontractors as much as to you: check workers have the skills and training for the job, give a site specific induction, and comply with the parts of the construction phase plan that cover their work.
Occupied homes add duties that sit with the landlord but land on site
Most funded retrofit happens with residents at home. Under Awaab's Law, social landlords keep full responsibility when they use contractors, and the government guidance for social landlords says contractors used for Awaab's Law work should report any other hazards they spot, along with safeguarding concerns. It also notes that a landlord can sometimes be treated as aware of a hazard when its contractor is, which starts the clock. Agree a same day reporting route for damp, mould, failed heating and anything unsafe, and make sure every operative knows it.
Ask how the subcontractor handles access, missed appointments and vulnerable residents, and who residents ring. On our programmes, resident liaison sits with the office team rather than with whoever is on site that day.
Capacity is a document, not a promise
A subcontractor who says they can start in four weeks should be able to name the supervisor, the number of operatives on each measure, and how many of them are already in post. Recruiting for a programme is normal, but you should see the roles and the timetable. Ours are public: we are hiring for programmes in the Leeds area and around Bath, mobilising from late 2026 into 2027, and every role is on our careers page.
Ask for a sample handover file from a finished job at the same time. At Torentum Court in Fleetwood we delivered the flat roof package inside a main contractor's programme: fifteen roofs and 768.75 m² of new warm roof, with residents at home throughout.
What to send a subcontractor before they price
Comparable prices need the same information on every return, so send each bidder the same pack:
- the number of homes, addresses or postcodes, and property types
- the measures in their package and who certifies each one
- the funding route, its lodgement rules and its deadlines
- who the Retrofit Coordinator is and what they need from installers
- programme dates, working hours and resident liaison arrangements
Whether the end client is a housing association, one of the councils delivering Warm Homes funding or a group of local authorities bidding together, the checks are the same. If you are subletting a measure package, our sub contracting page sets out how we work, and our supplier information pack has company details, certificates and policies ready for onboarding.
- Department for Energy Security and Net Zero: Warm Homes: Social Housing Fund Wave 3 scheme guidance (updated July 2026) (read 21 October 2026)
- TrustMark: Framework Operating Requirements V2.7 (21 May 2026) (read 21 October 2026)
- Health and Safety Executive: Contractors, roles and responsibilities under CDM 2015 (read 21 October 2026)
- Ministry of Housing, Communities and Local Government: Awaab’s Law Phase 2, guidance for social landlords (updated 31 July 2026) (read 21 October 2026)
Miles has led retrofit programmes at scale across the UK, with long-standing relationships with local authorities including Kirklees Council, Durham County Council and Ribble Valley Borough Council. He has project-directed programmes for housing associations and delivery partners including Aspire Housing, Sureserve, LivGreen and BroadOak, and for energy suppliers including E.ON Next, Utilita, British Gas and Octopus, and for tier one contractors including UKEM.