BS9251-2014, BS9999 and BS9991 Fire Sprinkler Regulations

BS 9251-2014 compliant residential fire sprinkler systems offered a very efficient compensation feature to satisfy building control fire safety regulations up to the 30th June when it was replaced by BS 9251-2021. These systems are a relatively new development, so much so that the Building Regulations Approved Document B did not make any mention of them in the 2000 edition.

The subsequent revision of Building Regulations Approved Document B (which addresses fire safety) in 2009 gave active fire systems, such as fire sprinkler systems, more weight than the passive systems previously preferred. Architects discovered that incorporating a residential fire sprinkler system into their projects could give them significant design freedom and cost savings.

However, Approved Document B is a prescriptive, rigid document that lacks flexibility. In simple cases, it was recommended that residential sprinklers could solve some fundamental difficulties, but they were very difficult to employ in more complicated ones, and ADB relaxations were usually at the building control officer’s discretion (BCO).

Introduction of BS9999:2008

Code of Practice For Fire Safety in the Design, Management and Use of Buildings

To address the issue of ADB’s inflexibility, BS9999:2008 was developed. This was accomplished by providing a more flexible approach that made use of fire engineering concepts to allow compromises or relaxations to build design if sprinkler systems were installed following BS EN 12845 and BS 9251. This guideline did not apply to individual homes and was mainly focused on larger complexes.

Introduction of BS9991:2011

Fire Safety in the Design, Management and Use of Residential Buildings

By focusing more on specific residential buildings and outlining trade-offs that can be made if fire sprinklers are installed as part of the project, BS9991:2011 was designed to complement BS9999:2008.

This standard permits the relaxation of standards for levels of fire resistance means of escape and fire alarm standards.

Relaxation of fire access requirements.

The New British Standard BS 9251:2021

This came into effect on the 30th of June 2021 and introduced various changes to the existing standard which mainly affect buildings over 18m.

The key changes from the BS9251:2015 version of the standard include the following:

There is now an additional category 4 introduced for residential buildings that have a topmost occupied floor level of 18m or above
Common areas of flats above 18m in height require sprinkler coverage
Non-residential areas like bin stores and plant rooms within some blocks of flats require coverage to BS EN 12845 commercial system
Apart from Category 1 systems, all in-line valves need to be monitored.
The sprinkler water supplies for categories over CAT1 have been enhanced and there is particular emphasis on enhanced power supplies for storage systems.
The coverage for some areas within a property that was exempt from coverage like bathrooms with an area less than 5m² is now dependent of the materials used within the area

Numerous household fire sprinkler systems can be connected to the town’s mains water supply. These systems cost about the same as fitted carpets when they are installed during the construction phase. These systems are made to last more than 50 years, in contrast to fitted carpets.