What does PAS 2030:2023 require from internal wall insulation installers?

PAS 2030:2023 requires internal wall insulation installers to employ operatives who hold vocational competence, or who are actively acquiring it. The installer must have at least 1 vocationally competent ("carded") operative for every 4 people at each location, and must check every operative's competence at least every 12 months. These rules are in Annex B.8 of the standard, which covers internal wall insulation as measure BFM.8.

PAS 2030 is the British Standards Institution (BSI) specification for installing energy efficiency measures in existing homes. Installers must be certified to it to work on schemes such as ECO4. The 2023 edition defines vocational competence (clause 3.27) as holding one of three things relevant to the measure being installed: a regulated, industry-agreed occupational qualification, an apprenticeship, or a personal certificate of competence. Each must include assessment of the person's practical ability in a real workplace.

Table B.8 of PAS 2030:2023 splits operatives into two groups:

Role in Table B.8 What PAS 2030:2023 requires What that means on site
Operative (specialist) Vocational competence (clause 3.27) Holds the relevant qualification, apprenticeship or competence certificate
Operative (threshold) Vocational competence being acquired (clause 3.28) Enrolled on a structured training or assessment programme
Competence ratio (B8-l6) No fewer than 1 carded operative per team of 4 (1 to 3) A team of 4 needs at least 1 qualified person at the property at all times
Competence currency (B8-l5) Checked by the installer at least every 12 months Qualifications stay valid, but the installer must re-confirm competence yearly
Supervision (B8-l6) Each task inspected and signed off by a vocationally competent operative Unqualified work is never left unchecked

The ratio is a minimum, not a target. PAS 2030:2023 tells installers to raise the ratio based on the scale and complexity of the work and how experienced the supervisor is.

Which qualification covers internal wall insulation?

The qualification that covers internal wall insulation is the Level 3 NVQ in Insulation and Building Treatments (Construction), Internal Insulation (Walls) pathway. City & Guilds and NOCN both award it. City & Guilds lists it as 5931-58. NOCN offers it within its Level 3 NVQ Diploma in Insulation and Building Treatments (Construction), which is on the Ofqual register as qualification 603/7207/2.

Qualification Awarding body Level Reference
Level 3 NVQ in Insulation and Building Treatments – Internal Insulation (Walls) City & Guilds 3 5931-58
Level 3 NVQ Diploma in Insulation and Building Treatments (Construction) – Internal Insulation (Walls) pathway NOCN 3 Ofqual 603/7207/2

An NVQ is assessed in the workplace, not in an exam hall. An assessor watches the candidate work on real installations, asks questions, and builds a portfolio of evidence. That is why NVQ candidates need to be working in the trade while they are assessed. The Ofqual register lists the NOCN Level 3 NVQ Diploma at 396 guided learning hours and 885 hours of total qualification time, covering all its pathways.

Is the internal wall insulation NVQ Level 2 or Level 3?

The current internal wall insulation NVQ is Level 3. City & Guilds' Level 2 NVQ pathways (5931-41 to 5931-46) cover:

  • cavity wall insulation
  • solid floor insulation
  • underfloor insulation
  • cold roof insulation
  • wood preserving and damp-proofing
  • wall tie replacement

Internal wall insulation now sits in the Level 3 range alongside external wall insulation, room-in-roof and hybrid wall.

Many training adverts still describe a "Level 2 internal wall insulation NVQ". That reflects an earlier version of the qualification. If you hold an older Level 2 certificate in internal insulation, ask your PAS 2030 certification body whether they still accept it as vocational competence for measure BFM.8. Do this before you rely on it for a funded job.

Do you need a qualification to install internal wall insulation on a private job?

No law requires a specific qualification to install internal wall insulation on a privately funded job in the UK. Qualification rules come from PAS 2030 certification, TrustMark and the funding schemes, not from statute. The work must still comply with the Building Regulations, which set a thermal performance target for the wall and require the installation to manage moisture.

In England, Approved Document L (2021 edition, Table 4.3) sets an improved U-value of 0.30 W/m²K for a wall upgraded with internal or external insulation. The U-value is the rate of heat loss through the wall: lower is better. If 0.30 W/m²K is not technically and functionally feasible, or would not pay back within 15 years, the wall should reach the lowest U-value that meets both tests (paragraph 4.13). Note 6 to Table 4.3 matters for internal insulation in particular. A lesser standard may be acceptable if reaching 0.30 W/m²K would cut the room's floor area by more than 5%.

Approved Document L also tells installers to pay particular attention to Parts B (fire), C (moisture), F (ventilation) and J (combustion appliances) when renovating a wall. Moisture is the main technical risk with internal insulation, because the original masonry ends up colder and dries more slowly. A qualified installer is trained to manage this.

What else does an internal wall insulation installer need?

An internal wall insulation installer typically needs four things besides the NVQ:

  • A CSCS card, to get onto most construction sites
  • CITB Health, Safety and Environment test, a pass within the last 2 years when applying for that card
  • An employer certified to PAS 2030:2023 and registered with TrustMark, for funded work
  • Working knowledge of the retrofit design, which PAS 2030:2023 requires the installer to check before starting
Requirement Who needs it Source of the rule
Level 3 NVQ (Internal Insulation (Walls)), or enrolment on one Each specialist operative; threshold operatives must be enrolled PAS 2030:2023, Table B.8
CSCS card (Gold Skilled Worker with a Level 3 NVQ) Operatives working on most construction sites CSCS
CITB Health, Safety and Environment test (passed within 2 years) CSCS card applicants CSCS
PAS 2030:2023 certification and TrustMark registration The installing business, for funded schemes Funding scheme rules
Pre-installation building inspection by a competent inspector The installing business, before every IWI job PAS 2030:2023, B.8.2–B.8.3

According to CSCS, the Gold Skilled Worker card is for people holding a construction-related NVQ or SVQ at Level 3, and lasts 5 years. A Level 2 NVQ leads to the Blue Skilled Worker card instead.

PAS 2030:2023 also makes the installer responsible for checks before any board goes on the wall. The installer must confirm that the retrofit design includes a moisture risk analysis, ventilation requirements and detailing for junctions such as embedded timber joist ends. Ventilation openings, flues and services must be located and protected. Every pre-installation inspection must be independently checked, and 1 in 10 of those checks must include a physical visit to the property.

Can you start installing internal wall insulation before you are qualified?

Yes. PAS 2030:2023 lets someone without the qualification work on internal wall insulation as a threshold operative, provided they are enrolled on a structured training or assessment programme (clause 3.28). They must work under supervision, and the team must keep at least 1 vocationally competent operative for every 3 people still training.

This is how most installers qualify. The NVQ is assessed on real jobs, so working as a supervised threshold operative is also how a candidate builds their evidence portfolio. A worker with no training programme in place cannot count towards the team on a PAS 2030 job.

Is an internal wall insulation qualification still worth getting in 2026?

An internal wall insulation qualification remains worth getting in 2026 because solid-wall homes still need insulating and the PAS 2030 competence rules apply whoever pays for the work. The funding landscape is changing, though. In its response of 23 January 2026, the government confirmed that ECO4 will end on 31 December 2026, and that there will be no successor supplier obligation.

The same government response kept ECO4's solid wall minimum requirement at its existing level until the scheme closes. It also committed £1.5 billion in additional grant funding for low-income households. Installers should expect government support for insulation to move from energy supplier obligations to grant schemes. Those grant schemes generally still require TrustMark registration and PAS 2030 certification, so the qualification stays relevant.

Frequently asked questions

How many qualified installers does PAS 2030 require on an internal wall insulation job?

PAS 2030:2023 requires at least 1 vocationally competent operative per team of 4 at the property at all times: a ratio of 1 to 3. The installer should use a higher ratio for complex or large jobs, or where the supervisor is newly qualified.

Do internal wall insulation qualifications expire?

An NVQ does not expire, but PAS 2030:2023 requires the installer to re-verify each operative's competence at least every 12 months. A CSCS card is valid for 5 years and must then be renewed.

Can a plasterer or dryliner install internal wall insulation without the NVQ?

On a PAS 2030 or funded job, a plasterer or dryliner without the internal wall insulation NVQ can only work as a threshold operative. That means being enrolled on a training programme and supervised by a qualified operative. Drylining experience helps with the practical work. It does not replace the measure-specific qualification, which also covers moisture risk, thermal bridging and ventilation.

Does internal wall insulation need Building Regulations approval?

Internal wall insulation must comply with the Building Regulations. PAS 2030:2023 requires installers to give the client a Building Regulations compliance certificate at handover, or explain that one will be provided within 30 days. In England, the upgraded wall should meet the Approved Document L standards described above.

What is the difference between a retrofit installer and a retrofit coordinator?

A retrofit installer is the business that physically fits the measure and must be certified to PAS 2030:2023. A retrofit coordinator oversees the whole project under PAS 2035, including the assessment, design and how the different measures interact. Each role has its own qualifications.

For the wider picture, see how to become a retrofit installer in the UK, which covers every measure and route.

How Nexis Academy can help

Nexis Academy is a City & Guilds Approved Centre (centre number T91185) based in Manchester, delivering practical internal wall insulation training aligned to PAS 2035 and PAS 2030. To check whether our training fits your experience and the route you need, see our City & Guilds approved internal wall insulation course or contact our team. Qualified insulation professionals interested in tutoring or assessing can read about careers at Nexis Academy.

Thinking of training or assessing others? See the Level 3 Award in Education and Training (AET) and the CAVA assessor qualification.

Sources