PAS 2035 - Specification for retrofitting of dwellings for improved energy efficiency

Elmhurst has directly contributed to the BSI working groups of both PAS 2030 and PAS 2035 and has a detailed knowledge of the proposed requirements, and an understanding of the issues that the documents are attempting to address.

Of course Elmhurst welcomes the issue of the draft PAS 2035 and completely support the notion that if we are to maximise the energy efficiency of a building, it must be with a "whole house" approach and planned to ensure that measures complement, and not detract, from each other.

We will be responding to this important review, and encourage our members to also take part in this. The Government see the new framework that Each Home Counts, of which PAS2035 (and PAS2030) play a key role, as the route to ensure good quality installs of energy efficiency measures.

Rather than list the many things that we support in this draft PAS, these comments focus on the few areas we would like changed:

Clause 4.3.2

RdSAP is the ideal tool to undertake an energy assessment of an existing dwelling when precise details are not known. Where details are known, or a more detailed analysis is required, full SAP is preferred. The calculation engines are the same in both and therefore combining the power of both is a good idea. Elmhurst would request the sentence:

"The use of RdSAP is not recommended because the software is known to make inaccurate default assumptions about some aspects of existing buildings"

be deleted as it is inaccurate, inflammatory and adds nothing to the paragraph.


Clause 5.2.2

We agree with the recommendation that the Retrofit Project Manager completes a "medium term low-carbon improvement plan" for all dwellings. However, this will only be possible if the assessment includes an assessment of energy consumption which is not currently a requirement in low risk buildings, as specified in Clause 8.3. An assessment of energy consultation should be required for all buildings and therefore the fifth and sixth bullets from clause 8.4 should be moved to 8.3 and applied to all buildings.


Clause 8.3

No installation measure, even those rated as low risk, should ever be considered until a calculated energy costs and savings has been undertaken. RdSAP EPCs are the government's chosen measuring stick for calculating and presenting improvements, therefore the use of alternative tools will cause confusion and influence government's own statistics. The fifth and sixth bullets from clause 8.4 should be moved to 8.3 and applied to all buildings


Clause 12

Every PAS 2035 specified installation measure should result in a new Energy Performance Certificate being issued to ensure government data accurately reflects the current state of our housing stock, update information held in the data warehouse, trigger an update to the Medium Term Plan and provide a reminder of further opportunities.


Clause 8 and Clause 9.

It is important that the property assessment is undertaken with the sole intent of maximising the energy efficiency potential of the building, and for the good of the occupants. This is best delivered if the Retrofit Assessment and Retrofit Design is undertaken separately, and independently from, the installation process. The involvement of an installer or manufacturer too early in the process, and before designing the optimum solution, will bias the design towards the manufacturers / installers own products.


Annex A1.2

It is correct that Energy Advisors should be trained however it is our belief that the C&G 6176 "Energy Awareness Training" qualification is limited to one provider. This is not acceptable and the requirement should be widened to include equivalent courses.


Clause 8.4

We agree that the energy assessment should include some form of occupancy assessment to ensure that the predicted savings, and decisions taken following the assessment, are appropriate for the current occupiers as well as for the good of the building.


Clause 8.5.1 and Annex A2.2

It is appropriate that the Retrofit assessment takes account of the RICS guidance note "Surveys of Residential Properties" but any requirement in A2.2 that they should be undertaken by RICS members should be removed. This is unnecessary, counterproductive (as chartered surveyors are not specialists in energy efficiency), incompatible with the requirement of being a DEA, and would massviely limit supply of Retrofit Assessors.

Elmhurst will be uploading our comments to the BSI portal and would encourage all our members to read the draft and submit their own comments direct to the working group before the deadline on 19th September 2018. The current aim is to attempt to get the PAS documents completed by early 2019. 

For link to PAS2035:

Deadline for Comments on draft: Wednesday 19th September 2018 

Article Published: 17th September 2018

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