PAS 2035 Retrofit Qualification: What It Is and Whether You Need It

‍‌​‌​​​‌‌​​​​​​‌‌‌‌​​​​‌​​‌‌‌​​‌‍PAS 2035 is basically the rulebook for doing energy retrofit properly rather than just chucking insulation at houses and hoping -- and it's where a huge chunk of future work is heading.

10.11.1 What PAS 2035 / PAS 2030 actually are

Think of PAS 2035 as the process, and PAS 2030 as the installation standard.

• PAS 2035:2019 -- sets out how domestic retrofit must be assessed, designed, managed and checked, from first survey through to handover and monitoring.
• PAS 2030:2019 -- sets out how each energy-efficiency measure (insulation, windows, heating, etc.) must be installed and what competence/certification installers need.
• TrustMark -- the government-endorsed quality mark; if you want to work on funded schemes (ECO4, Home Upgrade Grant, SHDF, BUS etc.), the job normally has to be TrustMark-registered and PAS-compliant.

Most retrofit funded by government or energy companies now requires PAS 2035/2030 and TrustMark.

Why the framework exists

PAS 2035 sits on top of:

• Part L of the Building Regs -- conservation of fuel and power; insulation levels, airtightness, efficient heating, etc.
• The Each Home Counts review (the "Bonfield Review", 2016) -- a government-commissioned review that found serious quality failures in earlier Green Deal and ECO installations. Homes were being insulated without proper assessment, ventilation was being ignored, and damp and mould problems were being created instead of solved. PAS 2035 is the direct result: a structured framework to stop that happening again.

10.11.2 The key roles in PAS 2035

The framework splits retrofit into specialist roles so one person isn't trying to do everything.

Retrofit Coordinator

• The project lead and compliance manager.
• Oversees the whole job: assessment, risk assessment, medium-term plan, design sign-off, installation oversight, handover and monitoring.
• Must be qualified (typically Level 5 Diploma in Retrofit Coordination and Risk) and accredited with a TrustMark-approved scheme.

Retrofit Assessor

• Surveys each dwelling -- collects data on the building, condition, occupancy, ventilation and energy performance.
• Must assess every dwelling, not just "one of each type" -- includes every flat in a block.
• Produces the Retrofit Assessment Report (including RdSAP/SAP/PHPP, condition and ventilation reports).

Retrofit Designer

• Turns the assessment and risk assessment into a detailed retrofit design: measure specifications, U-values, thermal bridging, ventilation strategy, sequencing.
• Must ensure designs meet PAS 2035, Part L and other relevant regs.

Installers (trades)

• Carry out the actual work -- insulation installers, heating engineers, window fitters, roofers, plasterers, MVHR installers, etc.
• Must be certified to PAS 2030 for each measure they install and registered with TrustMark if it's a funded job.

There are also advisor/evaluator roles in some frameworks, but for most trades the big three are Coordinator, Assessor, Designer -- you work with them as an installer.

10.11.3 How existing trades fit into the retrofit supply chain

This is where it gets interesting if you're already on the tools.

Insulation installers / dryliners / plasterers

• External wall insulation, internal wall insulation, cavity wall remediation, loft/roof insulation, floor insulation.
• Work is designed by the Retrofit Designer, overseen by the Coordinator, installed by PAS 2030-certified installers, then fire-stopped and made good.

Heating engineers / plumbers

• Boiler upgrades, heat pumps, hot water cylinders, pipework, controls, underfloor heating.
• Part L and MCS/PAS 2030 requirements apply -- many heat pump jobs need MCS as well (see below).

Electricians

• Controls, rewiring for new kit, electric heating, PV and battery (under MCS).
• Involved in improving efficiency, controls, and sometimes ventilation systems.

Carpenters / window and door fitters / roofers

• High-performance doors and windows, cold bridging details, airtightness detailing, roof upgrades.

Site supervisors / working foremen

• Natural candidates to step up into Retrofit Coordinator in time -- you already manage trades and understand how houses go together.

If you can already read drawings, understand Part L basics, and manage jobs, PAS 2035 is add-ons and structure, not a total re-learn.

10.11.4 Ventilation -- the single biggest risk in retrofit

This deserves its own call-out because it's where retrofit goes wrong most often.

• Insulate a house and don't upgrade the ventilation = mould, condensation, damp and health problems. This is exactly what the Bonfield Review found happening at scale in earlier schemes.
• Every PAS 2035 retrofit must include a ventilation assessment as part of the Retrofit Assessment Report.
• If you're installing insulation, windows or airtightness measures, the Retrofit Designer should have specified what ventilation changes are needed -- if they haven't, or if you're being told "just insulate it and don't worry about the ventilation", that's a red flag.
• MVHR (Mechanical Ventilation with Heat Recovery) installers are a growing specialism within the retrofit supply chain. If you're looking for a niche, this is one.

The reason PAS 2035 is so process-heavy is precisely because "just insulate it" without understanding the whole house caused serious harm to real people in real homes. The framework exists to stop that.

10.11.5 MCS and the Boiler Upgrade Scheme

If you're a heating engineer, MCS (Microgeneration Certification Scheme) is as important as PAS 2030 for accessing funded work.

• MCS certification is required to install heat pumps, solar PV and other renewable technologies where customers want to access government grants.
• The Boiler Upgrade Scheme (BUS) provides grants of £7,500 for air source heat pumps and £7,500 for ground source heat pumps (as of 2024 -- check current rates on gov.uk). The installer must be MCS-certified for the customer to claim.
• MCS certification involves an audit of your business, technical competence assessment, and ongoing compliance checks. It's a significant step up from standard Gas Safe/OFTEC registration.
• If you're a plumber or heating engineer looking at the long-term pipeline, MCS + PAS 2030 together unlock the biggest funding streams.

10.11.6 Why this matters for your future work

The UK has around 24 million homes that need energy upgrades, and most government-backed schemes now insist on PAS 2030/MCS and TrustMark.

Funding streams that currently require PAS/TrustMark

• ECO4 / ECO+ (Energy Company Obligation).
• Home Upgrade Grant (HUG).
• Social Housing Decarbonisation Fund (SHDF).
• Local Authority Delivery (LAD) schemes.
• Boiler Upgrade Scheme (BUS) -- via MCS.

Note: these schemes change regularly -- ECO4 runs to March 2026, HUG2 has specific deadlines, SHDF has funding waves. Always check current schemes on gov.uk and your scheme provider rather than relying on any list. New schemes will follow as the UK works towards net zero targets.

If you're not in the PAS/TrustMark world, you're locked out of a big, growing slice of work that will run for years.

10.11.7 Typical qualification pathways

You don't have to go straight to "Retrofit Coordinator". There are sensible steps depending on where you are now.

1) Staying on the tools, but retrofit-ready

• Keep your core trade qualifications (NVQ Level 2/3, ACS/Gas Safe, NICEIC, etc.).
• Add PAS 2030 certification for the measures you install, via an approved certification body.
• Do short retrofit awareness or "whole-house retrofit" courses -- many FE colleges and providers now run 1-3 day or Level 2/3 courses.
• Typical cost: PAS 2030 certification fees vary by scheme and trade but expect annual fees plus audit costs. Short awareness courses are often £200-£500, sometimes funded via CITB grants.

This makes you more attractive to main contractors and Coordinators who need reliable PAS-certified installers.

2) Retrofit Assessor

Good fit if you're an energy assessor, surveyor, or experienced trade who likes the surveying/technical side.

• Typically a Level 3 qualification in Retrofit Assessment (often built on domestic energy assessor skills).
• Training via providers like Retrofit Academy; accreditation with a scheme (Elmhurst, Stroma, etc.).
• Typical cost: £1,500-£3,000 for the qualification plus scheme registration fees.

3) Retrofit Designer

Good fit if you're an architect, technologist, engineer, or design-savvy trade with strong drawing/spec skills.

• Retrofit Designer training (Retrofit Academy and others offer Level 4/5 designer courses).
• Need to be comfortable with U-values, thermal bridging, ventilation design and Part L.
• Typical cost: £2,000-£4,000 for the qualification.

4) Retrofit Coordinator

This is effectively the project manager role for PAS 2035 jobs.

• Relevant background -- e.g. architecture, surveying, engineering, construction management, or NVQ Level 3+ in construction supervision.
• Level 5 Diploma in Retrofit Coordination and Risk (via Retrofit Academy or similar).
• TrustMark-approved scheme membership; Coordinator is responsible for PAS 2035 compliance and TrustMark lodgements.
• Typical cost: £3,000-£6,000+ for the diploma, plus several months of study and ongoing scheme fees.

If you're already a site manager, clerk of works, or experienced supervisor, this is a natural "off the tools" route with good day rates, but it does mean going back to study for a while.

10.11.8 TrustMark, lodgements and paperwork

For PAS 2035 jobs, especially funded schemes, the Retrofit Coordinator must lodge the project in the TrustMark Data Warehouse.

Typical documentation

• Retrofit Assessment Report (occupancy, condition, ventilation, energy modelling, medium-term plan).
• Retrofit designs for each measure -- including calculations and risk mitigation.
• Installation records, photos, commissioning and handover documents.

Funding is often only released once a compliant TrustMark lodgement exists. That's why Coordinators and PAS 2030 installers are becoming essential parts of the chain.

What to do next

If you're a hands-on tradie thinking about this:

• Decide whether you want to:
  • Stay on the tools but add PAS 2030 and retrofit awareness, or
  • Start stepping towards Assessor/Coordinator/Designer roles over the next few years.
• Speak to Retrofit Academy about entry requirements and course options at your level (installer awareness vs Assessor vs Coordinator).
• Check TrustMark for scheme requirements in your trade and what you'd need to get PAS 2030 certified.
• Talk to CITB and your local FE college about grants or funding for green skills/retrofit training -- there's often money on the table for this.
• If you're a heating engineer, look into MCS certification alongside PAS 2030 to access the Boiler Upgrade Scheme pipeline.
• Budget for it -- qualifications and certification aren't free. Factor in course fees, time off the tools, and annual scheme/certification costs before you commit.

This isn't a fad -- it's a long pipeline of work. Getting even a bit ahead of the curve now will make you more valuable than the lads who ignore it until the phone stops ringing for old-school boiler swaps and basic loft jobs.

Sources

• PAS 2035:2019 -- Retrofitting dwellings for improved energy efficiency -- specification and guidance. Published by BSI, commissioned by BEIS (now DESNZ).
• PAS 2030:2019 -- Specification for the installation of energy efficiency measures in existing buildings. Published by BSI.
• Building Regulations 2010, Part L -- legislation.gov.uk/uksi/2010/2214/contents/made -- conservation of fuel and power.
• Each Home Counts (Bonfield Review), 2016 -- government review of consumer protection, standards and enforcement for home energy efficiency and renewable energy measures.
• Climate Change Act 2008 -- legislation.gov.uk/ukpga/2008/27/contents -- the legal framework for UK net zero targets driving retrofit demand.
• TrustMark Framework Operating Requirements -- scheme rules for PAS 2035 lodgements and installer certification.
• MCS standards and certification requirements -- mcscertified.com.
• CITB green skills and retrofit training guidance.

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