PAS 2035:

2019 is a Publicly Available specification which, together with PAS 2030: 2019 provides a clear Retrofit Standards Framework when installing energy efficiency measures (EEMs). The framework has been designed to raise standards in both the design and installation of these measures, ensuring they are appropriate for the property and will perform as expected. 

How does PAS 2035 work?
PAS 2035 is based on the principal of a ‘whole-house approach’. This means that rather than installing measures ad-hoc, the property must first be carefully assessed and a clear 20-30 year improvement plan developed with a package of EEMs which are suitable to its particular characteristics. This plan should consider how EEMs will interact and set out an ordered schedule for their delivery.


What are the roles within PAS 2035?
A number of new positions are assigned under the Retrofit Standards Framework each with clear vocational or professional qualification requirements (contained within PAS 2030:2019 and PAS 2035:2019). Multiple roles can be carried out by the same individual providing they have the correct qualifications and any potential conflicts of interest are addressed.

The new roles are:
Retrofit Coordinator – Responsible for end-to-end oversight. The Coordinator commissions the other parties involved in the process and is responsible for protecting the owner and wider public interest and ensuring all work is completed in accordance with PAS 2035.
Retrofit Advisor – Liaises with homeowners to discuss the retrofit options which may be available for their property (this role is likely to be replaced with online or telephone advice services as part of proposed changes to the scheme).
Retrofit Assessor – Carries out the Whole-Dwelling Assessment, considering a property’s suitability for improvement based on factors such as its age, condition and any planning constraints.
Retrofit Designer – Develops the package of EEMs to be delivered on the property.
Retrofit Installer – Carries out the installation and commissioning of EEMs. They are responsible for ensuring (and demonstrating) that this work is in compliance with PAS 2030:2019.
Retrofit Evaluator – Assesses the performance of the property and reports back any concerns to the project team.

What are the typical stages in a PAS 2035 retrofit?
1.     The owners meet with the Retrofit Advisor to discuss ways to improve their home’s energy efficiency, including both the introduction of new measures and how they can be adapted to their own behaviour.
2.    If they wish to proceed with improvements, the Retrofit Coordinator carries out a Risk Assessment using a variety of sources. These include energy performance certificates (EPCs), occupant interviews and in-person assessments of the property. Based on this, the property is given a risk grade from C (high risk) to A (low risk).
3.    The Whole-Dwelling Assessment is then carried out by the Retrofit Assessor. For properties with a risk grade of B or C, this must include an analysis of ventilation and air permeability.
4.    Using the findings in this assessment, the Retrofit Designer then develops the package of EEMs. An Improvement Option Evaluation must also be prepared for dwellings on Risk Paths B or C, outlining the pay-back period and carbon cost effectiveness of the measures. 
5.    The Retrofit Coordinator develops the package into a clear 20-30 year property improvement plan, communicating this to the client and obtaining their approval for the work. 
6.    The Coordinator then briefs the Retrofit Installer who undertakes the installation and commissioning.
7.    The Retrofit Coordinator then arranges handover including guidance on how to operate any new technologies. All paperwork is retained by the Coordinator with copies made available to the owner. They will also recommend a new EPC is commissioned and carry this out where agreed.
8.    Finally, all projects are subject to evaluation. The Retrofit Evaluator conducts a Basic Evaluation within 3 months of commissioning including an owner questionnaire. If any issues are highlighted, then Intermediate or Advanced Evaluations may be carried out. These involve a variety of monitoring processes, including thermographic surveys and fuel metering and are carried out within 6 months (Intermediate) and 24 months (Advanced) of handover. Based on these, the Evaluator then makes recommendations for any remedial actions and circulates these to the other parties via the Data Warehouse.