Planning Portal

  1. Building Regulations
  2. Approved documents
  3. Approved Document B (Fire safety)
  4. FAQs
  5. Building Regulations Fire Safety (Part B) - Volume 1 DwellingHouses FAQs

Building Regulations Fire Safety (Part B) - Volume 1 DwellingHouses FAQs


Requirement B1 Means of Warning and Escape


  • Paragraph 1.3 asks for all new dwellinghouses to be provided with smoke alarms in accordance with the BS 5839-6:2004 to at least a Grade D category LD3 standard. However, table 1 of the BS recommends Grade D Category LD2?


For the purposes of Part B of the Building Regulations an LD3 system is considered to be adequate. The system itself should therefore be installed in accordance with the guidance for LD3 systems in BS 5839-6:2004.


  •  Now that door closers are no longer necessary within dwellings do I need them in a HMO?


The Housing Act 2004 replaced the previous housing fitness standard with a statutory framework for assessing and tackling hazards in housing - including fire hazards.

Within a house designated as a 'House in Multiple Occupation' such devices may still need to be provided between the private areas (ie bedrooms) and the common parts (ie circulation spaces, living room, kitchen etc).

This article:Approved Document B:No Simple Answer(PDF 405 Kb) on the Samuel Heath website may also be of interest.


  • When providing a protected stairway in a dwellinghouse, do I need to fit fire-resisting doors on the cupboards and bathrooms?


A protected stairway should be enclosed with fire resisting construction and fire resisting doors in order to protect people escaping down the stairs from a fire in the accommodation.

It may not always be necessary to provide fire doors on cupboards if they are small and the fire risk is low. An alternative to providing a fire door on a bathroom is to include the bathroom within the stair enclosure, thus removing the need for a fire door.


  • With reference to the new guidance on loft conversions, when providing new fire-resisting doors in an existing dwellinghouse, is it also necessary to replace the existing internal door frames?


A fire-resisting door should be regarded as a complete installed assembly. Thus the door, the frame and any ironmongery should be considered when assessing its suitability. In most cases, however, it should be possible to retain the existing frame. If in doubt, the test report for the door being installed will include details of the door frame in which it was tested.

Fire doors are often thicker and much heavier than other internal doors. Where existing frames are retained it may be necessary to replace or relocate the door stops and to install additional fixings back to the structure. The joint between the frame and the surrounding structure should be adequately sealed and the operating gap between the door and the frame should be kept to a minimum (usually 3-4mm).

Requirement B3 Internal Fire Spread (structure)


  •  Is it acceptable for a 110mm uPVC stack pipe to pass through a floor between an attached garage with a room above without being enclosed in a 30 minute fire-resisting casing?


 Item 2 of Table 3 (Maximum nominal internal diameter of pipes passing through fire separating element) now makes it clear that a uPVC pipe, up to 110mm in diameter, can pass through a wall or floor separating a dwellinghouse from an integral garage. The pipe should, however, still be fire stopped in accordance with paragraph 7.8. This would involve sealing around the pipe where it penetrates the wall or floor using a suitable material or a proprietary system as described in Paragraph 7.14.


Requirement B5 Access and facilities for the fire service


  • Is the 45m rule for firefighting access in paragraph 11.2 measured from the outside or from the front door?


Guidance in both Volumes of the Approved Document Part B states there should be vehicle access for a pump appliance to within 45m of all points within dwellings.  This is to take account of the actual distance that the fire fighters need to carry kit and lay hoses from the vehicle to reach a potential fire.


  • If the 45m rule for firefighting access in paragraph 11.2 cannot be achieved to all points within the dwellinghouse would the provision of a private fire hydrant directly outside the dwelling be a suitable alternative approach?


Provision of water supplies does not, on its own, reduce the physiological impact on firefighters of travelling long distances whilst carrying heavy equipment. Water from private hydrants may still need to be pumped before it can be used for firefighting. 

Where it is proposed to adopt an alternative approach to meeting requirement B5 (Access and facilities for the fire service). It would be advisable to seek the advice of the fire and rescue service who can advise on the practicalities of fire fighting.