This report supersedes BR265 (published in 1994) to address the increasing awareness of the importance of airtightness in commercial and public buildings. It supports the requirements on airtightness as specified in Approved Document L2 (2002 edition) which supports the Building Regulations (England and Wales). This report is intended as an outline guide to design, setting out the principles of providing an effective airtightness layer and advises on some common pitfalls. It covers
- 1) The mechanics that cause air infiltration to occur and the benefits which result from increasing the airtightness of a building
- 2) How to design and specify for airtightness
- 3) Site practice for airtight construction and testing a building to ensure that it meets the required standard. 33 pages.