BR135: Annex B. Performance criteria and classification method for BS 8414-2:2005
BRE (Building Research Establishment) is an independent, research-based consultancy, testing and training organisation, operating in the built environment and associated industries.
On 10 April 2007, BRE published BR135: Annex B. Performance criteria and classification method for BS 8414-2:2005, (Digest 501) by Sarah Colwell.
BR 135: Fire performance of external thermal insulation for walls of multistorey buildings, sets out the principles, design methodologies and fire spread performance characteristics for non-loadbearing cladding systems. It was written in response to the increasing use of thermal insulation in the refurbishment of multistorey buildings, which can offer a potential route for the spread of fire.
BR135: Annex B extends the coverage in Annex A of BRE 135 to cover cladding systems supported by a structural steel frame, in line with BS 8414-2:2005 Fire performance of external cladding systems. Part 2: Test method for non-loadbearing external cladding systems fixed to and supported by a structural steel frame.
It is a 4-page digest which presents a new classification system for the fire performance of cladding on multi-storey buildings. It is Illustrated with schematics and graphs showing a typical test facility and describes the test methodology and performance criteria for assessing systems which use framed structures.
[edit] Find out more
[edit] Related articles on Designing Buildings Wiki
- ACM cladding.
- BR 135: Fire performance of external thermal insulation for walls of multistorey buildings.
- BRE articles on Designing Buildings Wiki.
- BRE Buzz articles on Designing Buildings Wiki.
- BS 8414-2: Fire performance of external cladding systems.
- Building Research Establishment.
- External fire spread, Supplementary guidance to BR 187 incorporating probabilistic and time-based approaches.
- External fire spread: building separation and boundary distances (BR 187).
- Grenfell Tower fire.
- Sprinkler systems explained: A guide to sprinkler installation standards and rules.
- The role of codes, standards and approvals in delivering fire safety.
- Understanding the factors affecting flashover of a fire in modern buildings.
Featured articles and news
We're expanding our collaborative mission by launching DB Intelligence, an exclusive market research advisory panel. Built environment professionals can now get paid to share their expertise on industry trends, products and services.
Panel members receive direct financial incentives for participating in research projects like short surveys, 1-2-1 interviews and focus groups. Register today to shape the future of the construction sector.
Building Control Independent Panel final report
A precis of a key report led by Dame Hackitt with full recommendations and link to the government response.
Guide to ISO 19650 for Architecture Firms (2026)
A user gives their low down.
A UK training and membership provider for mould remediation professionals.
Building Safety recap April, 2026
A short and longer run-through of the month, with links to further information and sources.
CIAT May 2026 briefing.
Independent NSI and BAFE study exploring how organisations are changing the way they buy fire safety services.
From medieval scribes to modern word art.
ECA welcomes crackdown on late payment and push for clean energy, whilst CIOB seek fixed cladding removal timeframes.
Cyber Security in the Built Environment
Protecting projects, data, and digital assets: A CIOB Academy TIS.
Managing competence in the built environment
ITFG publishes new industry guide on how to meet the ICC principles.
The UK's campaign to reduce noise pollution: Mythbusting, articles and topic guides.