Gathering evidence to improve airtightness in the UK housing stock - phase 1

***Modification of the Contract*** Contract Variation PS23085 001 has extended the contract term from 31st January 2024 to 31st May 2024.

***** THIS IS AN AWARD NOTICE, NOT A CALL FOR COMPETITION *****

This procurement is being concluded following a competitive procurement exercise.

Brief Description of Requirement.

The Objectives for Phase 1 are:

1) Review what the current literature says about the airtightness, infiltration and ventilation of the existing UK housing stock and identify the gaps in the evidence base.

2) Identify what studies have been done to date and what data are currently available regarding the airtightness of the UK housing stock, broken down by building characteristics such as type/age/construction type/listed status etc.

3) Define what the n/20 rule used in SAP is, how it is currently used, what are its limitations and suggest proposals for a methodology to change/improve it.

4) Understand what is known about construction practices and risks relating to airtightness in the UK housing stock and whether there are typical failure points DocuSign Envelope ID: 2353E1FD-EC92-4E60-AEF0-8E1D7D2370B1 UK OFFICIAL during the construction process which lead to poor airtightness or increase the risk of overheating.

5) Provide recommendations and suggest aims, objectives and methodology for