Building Regs Part B Fire Safety

by Steve on November 15, 2009

Building Regs  Part B        

Fire Safety


Reference to:

Building Regs Part B

Smoke & heat detectors, wiring & positioning of,  OSG 7.5.2

Emergency Lighting


Also BS7671 Regulation 527 refers to:

The Selection and Erection of Wiring Systems to Mimimize the Spread of Fire.



The provision of Fire detection Systems.

All new dwelling houses should be provided with a fire detection & alarm system in accordance with BS5839-6 (Code of Practice for Design & Installation of Fire Detection and Alarm Systems in Dwellings) to at least Grade D Category L3.


Also new extensions to existing buildings and typical additions such as loft conversions may require a minimum of mains voltage Grade D alarm system to be linked to separate areas and to each floor level of a dwelling.


Care should be taken to select the correct type of fire detection device to suit its location.


Holes made in Walls and Ceilings

Walls and ceilings in a building may be designed to provide

fire resistance.  Penetrations in walls and ceilings made to accommodate mounting boxes or recessed lighting may compromise such a Fire Barrier.


Also BS7671 Regulation 527 refers to:  The Selection and Erection of Wiring Systems to Mimimize the Spread of Fire.


Emergency Lighting

Most emergency lighting schemes fall into one of the following categories:-

•Non-maintained – The emergency light units only illuminate in the event of a mains failure.
•Maintained – The emergency light units are illuminated at all times using the same lamps for both normal and emergency operation.
•Sustained – The emergency light units are fitted with two lamps or two sets of lamps. One of which operates on mains 240V AC supply, the other which operates from the battery supply in the event of mains failure. It is basically a non-maintained system with the addition of mains lamps which should be illuminated whenever the premises are occupied.
The type of system and emergency duration is often expressed in abbreviated form as per the following examples:-

•M3 – Maintained System, emergency duration 3 hours.
•NM2 – Non-maintained System, emergency duration 2 hours.
•S1 – Sustained System, emergency duration 1 hour.


More information on Emergency Lighting Systems.


View Approved Document B.


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