The revised PAS 2035:2023 and PAS 2030:2023 standards were published on 28 September 2023, according to the Retrofit Academy, an independent training body. The updates were recommended by the BSI Retrofit Standards Task Group and included input from TrustMark, the Department for Energy Security and Net Zero and the Scottish Government1.
The revised standards "incorporate lessons learned and reflect national policies, prioritising a whole-house retrofit approach and sustainability"1. PAS 2035 was first published in May 2019, following the Each Home Counts Review, which the Retrofit Academy says uncovered systemic failures and poor standards in retrofit delivery, with problems such as dampness, mould and condensation left behind1.
Changes in PAS 2035:2023 include requiring Medium-Term Improvement Plans for all projects, strengthened guidance on airtightness, moisture management and ventilation, greater emphasis on climate adaptation and mitigation, and specific provisions for traditional or historic buildings1. For those buildings, the standard mandates adherence to BS 7913, the guide to the conservation of historic buildings. Such projects are typically categorised as high-risk and require professionals to hold specialised qualifications, such as the ABBE Level 3 Award in Energy Efficiency and Retrofit of Traditional Buildings1.
The standard sets out four key roles: retrofit assessor, retrofit coordinator, retrofit designer and retrofit installer1. Compliance with PAS 2035 is mandatory for retrofit projects using government funding, such as the Energy Company Obligation and the Warm Homes programme, while businesses not using public funding are encouraged to adopt it voluntarily1. The Retrofit Academy states that a simplified version of the Significance Assessment defined in BS 7913, applicable in Path B only, can be downloaded free from the BSI website1.
| Item | Detail |
|---|---|
| Published | 28 September 2023 |
| Full operation | 30th March 2025 |
| Transition period | 18 months |
| First PAS 2035 publication | May 2019 |
Why it matters for households
The PAS 2035 and PAS 2030 retrofit standards govern how retrofit work is planned and delivered, and compliance is a condition of government-funded programmes. For a household, the practical effect is that a project should be assessed as a whole house rather than as a set of separate measures, with ventilation and moisture management considered alongside insulation and airtightness. The Retrofit Academy notes that making buildings more airtight without ventilating them properly commonly leads to dampness, mould and condensation1. The standards also introduce defined roles and a sequence for projects, which the body says puts protection of the homeowner at the centre of the process1.
The revised standards sit within wider regulation and policy for home energy, including the work of DESNZ. Households in Scotland may also be affected by separate energy efficiency rules for privately rented homes, covered in the site's guide to energy efficiency standards for privately rented homes in Scotland. Schemes that have since closed are tracked in the guide to closed and abandoned home energy policies.
What happens next
Projects initiated under the 2019 standards could continue during the 18-month transition period, provided they met the existing requirements. From 30th March 2025, all retrofit projects must comply with PAS 2035:20231. The transition period was intended to allow businesses, certification bodies and training providers time to adopt the new standards1. No further changes to the standards have been reported.
Sources1 cited
- PAS 2035 Guide - Retrofit Academy, retrofitacademy.org