About Retrohaus
An accredited energy consultancy, accountable for every figure
Retrohaus Energy Consultancy is an accredited team of energy assessors and retrofit professionals based in Coventry. We certify how buildings perform, assess what they need and coordinate the work that improves them, for households, landlords, housing providers, local authorities and installers across the Midlands.
Evidence for better buildings
Those four words are on our logo because they describe the job. A certificate, a retrofit plan or a piece of advice is only worth having if it rests on what is really there: the wall as it was built, the insulation at the depth it was laid, the boiler that is on the wall and not the one in the brochure.
So we measure. We photograph. We ask for the paperwork, and we read it. When something cannot be proven we say so, and we tell you what would settle it.
That is now the standard the whole industry is held to. Since October 2026 domestic energy assessors have had to hold evidence for every figure they enter, and funded retrofit projects have to be recorded at every stage. We welcome it, because it is how we were working already.
We have one more rule: we install nothing. We do not fit or sell insulation, heating or solar panels. What we tell you about a building is what the survey shows.
What we do
We certify, we assess and we coordinate.
Three disciplines that follow one another in the life of a building, carried out by one team to one standard of evidence.
Energy Performance Certificates
For homes, rented property and business premises that are being sold, let or completed. Surveyed in person and lodged on the government register. We draw measured floor plans from the same visit.
CertificatesRetrofit Assessment
The PAS 2035 whole-home survey that the Warm Homes schemes require before any improvement work: condition, occupancy, ventilation and energy. It is also where our energy advice begins.
Retrofit assessmentRetrofit Coordination
A Retrofit Coordinator who takes responsibility for a project from the first survey to TrustMark lodgement, on a single home or across a whole programme.
Retrofit coordinationWho we work with
Households, landlords, housing providers and installers.
Retrohaus Energy Consultancy provides retrofit assessment and retrofit coordination for homes improved under Warm Homes schemes, and we support the social housing providers and local authorities that deliver them.
We also support solar PV and air source heat pump (ASHP) installers, including the work they deliver under grant schemes, with the assessments, the coordination and the certificates that the rules require.
Alongside that work we do what many people first need from us: an Energy Performance Certificate for a sale or a letting, produced properly and without delay.
Homeowners and landlords
Certificates, floor plans, and straight advice on what would improve a property and which grants could help.
Estate and letting agents
EPCs and floor plans turned round reliably, with access arranged directly with the occupier.
Social housing providers
Retrofit assessment and coordination for programmes under the Warm Homes: Social Housing Fund, and EPCs across the stock.
Local authorities
Assessment and coordination for homes improved under the Warm Homes: Local Grant and other funded schemes.
Solar PV and heat pump installers
An independent assessor and Retrofit Coordinator for funded and private work, with the evidence file and lodgement handled properly.
Commercial owners and agents
Non-domestic EPCs for shops, offices and industrial units, and a clear view of the minimum standards.
How we work
Six principles that shape every job.
- We survey in person.Every certificate and every assessment starts with a visit. There are no desktop shortcuts.
- We record the evidence.Measurements, photographs and documents for everything we enter, kept so that an auditor could reproduce the result from our file.
- We explain what we find.You get the result and a plain-English account of what lies behind it, including what would change it.
- We stay independent.We do not fit or sell insulation, heating or solar panels, so the only thing we have to offer is an accurate account of the building.
- We work to the published standards.RdSAP 10 for homes, SBEM for commercial buildings and PAS 2035:2023 for retrofit, applied as written.
- We answer for our work.Each certificate carries our assessor's name and is open to audit by our accreditation scheme. If we have made a mistake, we correct it.
The standards behind our work
What we produce follows published methods, and each result can be checked against them.
| Standard | What it governs | Where we use it |
|---|---|---|
| RdSAP 10 | The calculation behind every EPC for an existing home, in use since June 2025 | Domestic EPCs and retrofit assessments |
| SBEM | The calculation for most non-domestic buildings | Commercial EPCs at levels 3 and 4 |
| Minimum evidence requirements | What a domestic energy assessor must photograph, measure and keep, in force since 1 October 2026 | Every domestic EPC we lodge |
| PAS 2035:2023 | The national standard for the energy retrofit of homes | Retrofit assessment and retrofit coordination |
| TrustMark lodgement | The record of a completed retrofit project | Every PAS 2035 project we coordinate |
The company behind the name
Retrohaus Energy Consultancy is a trading name of Build Net Zero Limited, a company registered in England and Wales under number 16646393. Our registered office is 49 Courtelle Road, Coventry, CV6 5FH.
You do not have to take our word for any of this. Our accreditations page shows how to look us up on the government's assessor register and on TrustMark, and what to do if you are ever unhappy with our work.
Accreditation
Accredited through three schemes, and TrustMark registered.
Energy assessors must belong to a government-approved accreditation scheme, which checks their qualifications, requires insurance and ongoing training, and audits their certificates. Our assessors are accredited through Elmhurst Energy, ECMK and Quidos. Retrohaus is registered with TrustMark, the Government Endorsed Quality Scheme.
See what each accreditation means
Where we work
Coventry first, then the Midlands.
We are based in Coventry and most of our surveys are within 25 miles of the city: Nuneaton, Bedworth and Hinckley to the north, Rugby to the east, Leamington Spa and Warwick to the south, Solihull and Birmingham to the west, and Leicester to the north-east. Every service is available in every one of them.
We travel further for portfolios, commercial buildings and retrofit programmes, and retrofit coordination is available nationwide.