What is PAS2035? – Ep.41

PAS 2035 is the government-backed framework that sets out how retrofit projects in the UK should be planned, delivered, and overseen. Introduced to address the well-documented failures of earlier retrofit programmes, it establishes a structured process that runs from the initial property assessment all the way through to post-occupancy evaluation — covering who should be involved at every stage, what their competencies need to be, and how risks should be identified and managed throughout. In practice, it applies specifically to projects accessing government funding, such as ECO or Warm Homes Grant schemes, rather than privately funded works.

At the heart of the framework are two key roles: the retrofit coordinator and the retrofit designer. The coordinator acts as the guardian of the process, responsible for ensuring PAS 2035 is followed correctly, that all the right people are in place, and that the substantial paperwork requirements are met. The retrofit designer — often an architect or Passivhaus designer with additional retrofit-specific training — is responsible for ensuring the work is properly designed. Installers, meanwhile, operate under the companion standard PAS 2030, which sets out measure-specific requirements including checks before, during, and after installation.

Certification for installers involves a combination of NVQ-level operative qualifications, company accreditation, and appropriate insurances — all of which feed into the system of insurance-backed guarantees that protect the homeowner. From a materials perspective, products with an Agrément certificate can plug into this chain, allowing warranty providers such as the Insulation Assurance Authority or Quality Mark to offer 25-year insurance-backed guarantees to certified installers. It’s a complex structure, but one built specifically to ensure that the industry’s hard-won knowledge about retrofit risks is consistently applied by the right people at the right time.