PAS 2038 Retrofit Assessments

Our PAS 2038 assessment is a thorough, whole-building evaluation designed to map out a clear path to decarbonisation. It focuses on four critical pillars:

The Building’s Context & Heritage: Identifying planning constraints, conservation area rules, and architectural significance.

Fabric & Building Condition: Inspecting the physical state of the walls, roof, floors, windows, and existing services.

Occupancy Assessment: Evaluating how the building is actually used, its operating hours, and occupant behaviour to ensure recommendations are practical.

Energy Performance: Establishing an energy baseline using Non-Domestic EPC modelling.

To give our clients deeper insights, we regularly combine the core assessment with advanced diagnostic testing, including air tightness testing and thermal imaging surveys.

You will receive a comprehensive, audit-ready technical package. Key deliverables include:

An Improvement Option Evaluation (IOE) Model: A detailed analysis showing which retrofit measures will deliver the best return on investment and carbon savings.

A Non-Domestic Energy Performance Certificate (EPC): Updated to reflect the building’s current baseline and future potential.

A Fabric-First Retrofit Roadmap: A step-by-step plan that prioritises building fabric upgrades (insulation, glazing) before specifying low-carbon heating systems like Air Source Heat Pumps.

A Diagnostic Report Summary: If you opt for our advanced testing packages, we will also deliver a comprehensive diagnostic report. This includes high-resolution thermal imaging hot-spot maps (to locate hidden heat loss) and air permeability data (from our airtightness testing) to precisely guide the design stage.

Yes. We specialise in balancing modern energy targets with strict historical preservation. At St Saviours Hall, a Grade-unlisted community hall built in 1886 within Plymouth’s Barbican Conservation Area, standard insulation and heating options were limited by the building’s solid-limestone construction and original wooden windows. We assessed all 13 zones individually – rather than sampling – and used thermal imaging and air tightness testing to pinpoint exact heat loss, recommending targeted insulation and window repair rather than replacement, so the retrofit strategy respected the building’s historic character while still improving its thermal performance.

Yes, across the full range of school scales. At Brookfield Primary School, a 3,398m² multi-storey Victorian building in London built across four separate construction periods spanning the pre-1900 original building to a 1990s extension, we ran a defined first-phase assessment across nine classrooms, combining a full condition survey with phased air tightness testing (whole-building result: 6.48 m³/hr·m², assessed as good for a building of this age). At the smaller, more specialist end, we’ve also delivered a single-assessor PAS 2038 survey of an occupied boarding house at an independent school – our assessors hold DBS clearance as standard, and here the visit was coordinated around confirmed clearance checks and pupil timetables, with the full fabric and services assessment completed in two days despite the site sitting over 600 miles from our Bristol base.

This is a common headache for local authorities and housing associations, and it’s a core strength of ours. On a recent Warm Homes: Social Housing Fund programme for a Lewisham Council, we assessed two sheltered housing blocks combining 51 individual flats and 2 guest flats with shared communal spaces and building services. Because of this layout, the project needed two compliance pathways run as one unified exercise – our team applied PAS 2035 to the residential dwellings and PAS 2038 to the communal areas, including a Commercial EPC for the shared plant and building services, ensuring the whole building achieved compliance without gaps or funding risk.

While not yet a universal legal requirement for all private projects, PAS 2038 is increasingly mandated for public sector schemes. If you’re applying for funding under schemes like the Public Sector Decarbonisation Scheme (PSDS) or the Public Sector Low Carbon Skills Fund (LCSF), a robust, PAS 2038-compliant assessment and heat decarbonisation roadmap is critical to securing your grant. The same applies to mixed-use social housing portfolios funded through the Warm Homes: Social Housing Fund, where any communal areas or shared central heating systems must be assessed under PAS 2038 alongside the domestic PAS 2035 assessments.

For private asset managers, landlords, and institutional investors, PAS 2038 is the gold standard for “proof of concept”. To access sustainability-linked commercial loans, green bonds or ESG investment capital, lenders require verifiable evidence that your retrofit will actually deliver real-world carbon reductions.

A PAS 2038 assessment bridges the traditional “performance gap” (where design theory doesn’t match actual post-construction utility bills). It provides the highly accurate, modelled energy baseline and logical improvement plan that green lenders demand to satisfy their underwriting criteria.

Yes. One of the biggest financial risks in retrofitting is funding clawbacks due to unintended consequences (such as introducing damp/mould through improper insulation) or failing to hit target carbon reductions. Because PAS 2038 enforces a rigorous, multi-disciplinary process – including baseline modelling, strict installation oversight and post-occupancy performance evaluation – it acts as a professional shield, protecting your organisation’s capital investment and ensuring compliance under audit.

While PAS 2035 is the framework for domestic (residential) properties, PAS 2038 is designed specifically for the unique complexities of commercial and non-domestic buildings.

PAS 2035 projects are managed by a Retrofit Coordinator. Because of the scale of commercial properties, PAS 2038 instead requires a Retrofit Lead Professional to manage the project team and oversee delivery.

For very small commercial buildings (under 500m²), PAS 2038 actually allows you to use the PAS 2035 domestic methodology – provided the building has domestic-style services, is no more than three storeys, and the coordinator is a qualified Non-Domestic Energy Assessor (NDEA).

Because commercial buildings vary drastically in size, age, and service complexity, pricing is tailored to the specific scope of your property. However, we regularly review our commercial rate cards to ensure we offer the best value in the industry. If you have found a lower quote for a comparable, fully compliant PAS 2038 assessment, let us know – we will match or beat it where we can.

While we’re proudly based in Bristol, our specialist team operates nationwide. We routinely deliver commercial assessments, diagnostic testing and decarbonisation roadmaps for public and private sector clients right across the UK – including recent work in Scotland, Plymouth and London.