BTS Reacts to PAS 2035 Release

On the 30th June 2019, the British Standards Institute (BSI) released the long awaited PAS 2035; the new framework for retrofitting dwellings for improved energy efficiency. This new standard is supported by the UK Government’s Department for Business, Energy and Industrial Strategy (BEIS), and was developed by a Steering Group which included many stakeholders from the Built Environment and Retrofit industry.

Building elements of a house

PAS 2035 is the new over-arching document in the retrofit standards framework that provides a specification for the energy retrofit of domestic buildings, and details best practice guidance for domestic retrofit projects.

Build Test Solutions was one such organisation involved in the preparation of this new PAS document; contributing some of their own technical insight to help build a new standard for the future.

Initially set to underpin Government-backed retrofit schemes carried out in the UK, the standard adopts a risk based approach to retrofit assessment, design, measurement, verification as well as the provision of handover advice:

Build Test Solutions response to new PAS 2035 document:

PAS 2035 combined with PAS 2030 (which concerns installation, testing commissioning and handover) stands to serve as a real game changer in the way that retrofits are designed and assessed. As strong advocates of building performance measurement and post occupancy evaluation, BTS were eager to see that air permeability testing, heat loss measurement and ventilation system assessment were all part of the retrofit design and commissioning process. Measurement of performance pre works can ensure that the most appropriate solutions are designed and installed whilst post works measurement will ensure that intended quality outcomes have been delivered. Our own Pulse air permeability measurement device, leak checker fanSmart HTC and rapid U-value measurement have all been developed for quick and easy use within a Retrofit projects.


Luke Smith

Luke Smith

Managing Director

Building performance measurement made simple.

Unique products and smart technologies designed for energy assessors, building surveyors, the construction industry, utility suppliers and other built environment experts.

Pulse air receiver, controller and compressor

Pulse Air Permeability Testing

A pioneering approach to fabric air permeability measurement that releases a low-pressure pulse of air for realistic and accurate measurement of airtightness of buildings in seconds.

Learn more about Pulse Air Permeability Testing
Leak Checker Diagnostics Fan

Leak Checker Diagnostics Fan

A portable diagnostics fan that can help identify air leakage paths within buildings, helping to minimise infiltration, improve airtightness and reduce remedial work required to pass compliance testing.

Learn more about Leak Checker Diagnostics Fan