Section H Building Regulations and Other Guidance
Part B Fire Safety Volume 2
Part C Site Preparation and Resistance to Moisture
Part J Heat Producing Appliances
Part L Energy Conservation
Part L 2019
Part L1 Dwellings 2017
Heating and Domestic Hot Water Systems for dwellings - Part L
Timber Frame Construction
Acceptable Construction Details
External Wall Insualtion
Insulation in Cavity
Insulation Cavity Block
Typical Inspection Reports
Use of the Guidance
0.1.1 Fire Safety objectives
Building Regulations are made for specific purposes. Part B of the Second Schedule to the Building Regulations is therefore primarily concerned with the health, safety and welfare of persons. The fire safety measures outlined in this guidance document are intended for the protection of life from fire.
0.1.2 Technical Guidance Document B-Fire safety (TGD B) is published in two volumes.
Volume 1, deals with all other types of buildings covered by the Building Regulations excluding dwelling houses.
Volume 2, deals solely with dwelling houses. Volume 2 gives guidance which relates to non-complex dwelling houses of normal design and construction and timber frame to I.S 440. Where very large or unusual dwelling houses (over 15m in height), are proposed, or where an alternative approach is required, some of the guidance in Volume 1 may be needed to supplement that given by Volume 2.
0.1.3 Application of Part B
Part B of the Second Schedule to the Building Regulations is primarily concerned with securing the health, safety and welfare of persons in or about buildings. This volume deals with the requirements of B6 - B10 relating to dwelling houses:
B6 aims to ensure that a satisfactory standard of early warning and means of escape is provided for persons in the event of fire in a dwelling house;
B7 aims to ensure that fire spread over the internal linings of dwelling houses is inhibited;
B8 aims to ensure the stability of dwelling houses in the event of fire, that there is a
sufficient degree of fire separation within dwelling houses and between adjoining buildings, (including dwelling houses) and to inhibit the unseen spread of fire and smoke in concealed spaces in dwelling houses;
B9 aims to ensure that external walls and roofs have adequate resistance to the spread of fire over their external surfaces, and that spread of fire from one building to another is restricted; and
B10 aims to ensure satisfactory access for fire appliances to dwelling houses and appropriate facilities in dwelling houses to assist fire fighters in the protection of life and property.
0.1.4 Arrangements of Sections
The provisions set out in Sections 1 to 5 of this Document, deal with the five Requirements of the Building Regulations as outlined above. The five sections, in addition to this one dealing with general provisions, are:
S1 Means of warning and escape in case of fire
S2 Internal Fire Spread (linings)
S3 Internal Fire Spread (structure)
S4 External Fire Spread
S5 Access and Facilities for the Fire Service
0.1.5 Purpose Groups
Many of the provisions in this Document are related to the use of the building. The use classifications are termed purpose groups and from this it follows that the relevant purpose group should be decided before the provisions can be determined.
The provisions in this Document are related to the purpose groups outlined in Table 0.1
Table HB1 - Classification of buildings by purpose group - Extract from TGD B Vol. 2
Note 1 Purpose Groups 1(a) and 1(b) include: • any surgery, consulting rooms, office or other (professional rooms) accommodation not exceeding 50m2 forming part of a dwelling house and used by the occupant of the dwelling house in a professional capacity.
Note 2 Purpose Groups 1(a) ,1(b) and 1(d) include:
- a domestic garage within the envelope of the dwelling house.
0.1.6 Interaction of Provisions
Whilst provisions appropriate to B6 to B10 are set out separately in Sections 1 to 5 in this Document, many of the provisions are closely interlinked. For example, there is a close link between the provisions for means of escape (S1) and those for the control of fire growth (S2), fire containment (S3), and facilities for the fire service (S5). Similarly there are links between S3 and the provisions for controlling external fire spread (S4), and between S3 and S5.
Interaction between these different requirements should be recognised where variations in the standard of provision are being considered. A higher standard under one of the requirements may be of benefit in respect of one or more of the other requirements. Thus the provisions in the Document as a whole should be considered as a package aimed at achieving an acceptable standard of fire safety.
0.1.7 Performance Statements
At the start of Sections S1 to S5, the relevant requirement of the Regulations is set out and is followed by a performance statement which indicates how the requirement may be met. These statements incorporate the essential elements required to satisfy the regulations and form the basis for the provisions contained in the guidance.
0.1.8 Alternative Solutions
The detailed provisions set out in this Document are intended to provide guidance for some of the more common building situations. In other situations, alternative ways of achieving compliance with the requirements of Part B of the Second Schedule to the Building Regulations may be appropriate. There is no obligation to adopt any particular solution contained herein. The use of alternative design solutions, standards, systems or methods of fire protection to those outlined in this document is acceptable, provided the level of fire safety achieved is adequate to satisfy the requirements of the Building Regulations.
0.1.9 Existing Buildings
In the case of an existing building there may be constraints that would not exist with a new building and some variation of the provisions set out in this Document may be appropriate.
Alternative solutions whether applied to all or part of the building or to specific provisions, may be employed in these situations. Also note that exceptions are allowed in 1.3.8 in relation to existing internal stairways.
Many fire safety provisions are interdependent and should not be considered in isolation. Where a particular provision outlined in this Document cannot be practicably achieved, account may be taken of compensating fire safety measures, depending on the nature and circumstances of each particular case.
Such measures would include active and / or passive provisions. Active provisions are those which come into action on detection of fire (such as fire suppression systems) while passive provisions relate to the defence against fire provided by the fabric and construction of a building (such as floors and walls).
Further guidance on effective and feasible recommendations and selection criteria for the use of passive fire protection (PFP) systems in buildings is given in “Ensuring best practice for passive fire protection in buildings” published by the Association of Specialist Fire Protection (ASFP).
A number of useful publications are available which outline alternative approaches to fire safety in existing buildings of special or historic merit. These include:
Architectural Heritage Protection Guidelines for Planning Authorities Chapter 7 and Chapter 17 published by the DAHG 2011;
Fire protection in old buildings and historic town centers, published by the Fire Protection Association;
Fire protection measures for the Royal Palaces, Department of National Heritage, London; and
Heritage under fire, a guide to the protection of historic buildings by the United Kingdom Working Party on Fire Safety in historic buildings.
Guide for Practitioners 6: Conversion of Traditional Buildings by Historic Scotland
0.1.10 Operation, maintenance and use
Sufficient clear and comprehensive information on any continuing maintenance should be provided to the owner where a Fire Detection and Alarm System (FDAS) or a fire suppression system is installed in the dwelling house.
0.1.11 Fire Performance of Materials and Structures: Appendix A
Many of the provisions throughout this publication are given in terms of performance in relation to standard fire test methods. Details are drawn together in Appendix A and reference is made where appropriate in Sections 1 to 5.
0.1.12 Fire Doors: Appendix B
Provisions in respect of fire doors are set out in Appendix B. Fire doors may play a significant part in the fire safety of some dwelling houses. It is important to note that a fire door refers to a complete door assembly and not the door leaf alone.
0.1.13 Methods of measurement: Appendix C
Some form of measurement is an integral part of many of the provisions in this publication, and methods of measurement are set out in Appendix C.
0.1.14 Loft Conversions: Appendix D
Provision in respect of Loft conversions in existing one and two storey dwellings are set out in Appendix D.
0.1.15 Referenced Standards and Publications
For convenience standards and publications are referenced after the Appendices in this Document
0.1.16 Independent schemes of Certification
Third party certification installers of systems, materials, products or structures can provide a means of ensuring that installations have been conducted by competent contractors to appropriate standards, thereby increasing the reliability of the anticipated performance in fire. (See Technical Guidance Document D – Materials and Workmanship)
For the purposes of this document, the following terms and definitions apply. These definitions are additional to those to be found in TGD Part B: Volume 1: Buildings other than dwelling houses
Access room – The room through which occupants of an inner room must pass in order to escape.
Appliance ventilation duct – A duct provided to convey combustion air to an appliance.
Access level – A level used for normal access to a building that either incorporates, or leads directly to, a place of safety.
Alternative escape routes – Escape routes sufficiently separated by either direction and space, or by fire-resisting construction, to ensure that one is still available should the other be affected by fire.
Basement storey – means a storey which is below the ground storey or, where there is no ground storey, means a storey the top surface of the floor of which is situated at such a level or levels that some point on its perimeter is more than 1.2 m below the level of the finished surface of the ground adjoining the building in the vicinity of that point.
Bedroom – A room within a dwelling or building which is used as sleeping accommodation.
Boundary – The boundary of the land belonging to the building, or where the land abuts a road, railway, canal or river, the centreline of that road, railway, canal or river (see Diagram15).
Conservatory – A single storey part of a building where the roof and walls are substantially glazed with a transparent or translucent material.
Cavity barrier – A construction provided to close a concealed space against penetration of smoke or flame or provided to restrict the movement of smoke or flame within such a space.
Ceiling - A part of a building which encloses and is exposed overhead in a room or circulation space (the soffit of a rooflight is included as part of its surface but not the frame).
Circulation space- A space (including a protected stairway) mainly used as a means of access between a room and an exit from the building or compartment.
Class 0- see appendix A - A12
Community dwelling house - a dwelling house with a maximum of 8 bedrooms which may have no more than one storey, the floor level of which is more than 4.5 m above ground level occupied as a group home, under the management of a statutory or voluntary organization providing supported living and residential services.
Compartment - A building or part of a building, comprising one or more rooms, spaces or storeys, constructed to prevent the spread of fire to or from another part of the same building, or an adjoining building.
Compartment wall or floor - A fire resisting wall/floor used in the separation of one fire compartment from another (constructional requirements are given in 3.5 of Section 3).
Concealed space (cavity) - A space enclosed by elements of a building (including a suspended ceiling) or contained within an element, but not a room, cupboard, circulation space, protected shaft or space within a flue, chute, duct, pipe or conduit.
Dead-end – Area from which escape is possible in one direction only.
Domestic garage – Means a building ancillary to a dwelling which is used, or suitable for use, for the storage of a motor vehicle or vehicles and is not used for the purposes of any trade or business.
Dwelling – A house or flat, forming a separate unit of residential accommodation.
Dwelling house – means a dwelling that is not a flat (as defined in S.I.497 of 1997).
Emergency lighting – Lighting provided for use when the power supply to the normal lighting fails.
Electro-magnetic, or electro-mechanical device susceptible to smoke – A device which will allow a door held open by it to close automatically in the event of each or any one of the following:
detection of smoke by automatic apparatus suitable in nature, quality and location, and
operation of a manually operated switch fitted in a suitable position, and
failure of the electricity supply to the device, apparatus or switch, and
operation of the fire alarm system, if any.
Escape route – A route by which a person may reach a place of safety, and, in relation to any point in a building, a route from that point to a place of safety.
External wall - (or side of a building for the purposes of B9) includes a part of a roof pitched at an angle of 70° or more to the horizontal - if that part of the roof adjoins a space within the building to which persons have access (but not access only for repair or maintenance).
Final exit – The termination of an escape route from a building giving direct access to a street, passageway, walkway or open space, and sited to ensure the rapid dispersal of persons from the vicinity of a building so that they are no longer in danger from fire and/or smoke.
Fire door – A door or shutter, provided for the passage of persons, air or objects, which together with its frame and furniture as installed in a building is intended when closed to resist the passage of fire and/or gaseous products of combustion, and is capable of meeting specified performance criteria to those ends. (It may have one or more leaves and includes a cover or other form of protection to an opening in a fire resisting wall or floor, or in a structure surrounding a protected shaft).
Fire stop – A seal provided to close an imperfection of fit or design tolerance between elements or components, to restrict or prevent the passage of fire and smoke
Flat – separate and self-contained premises constructed or adapted for residential use and forming part of a building from some other part of which it is divided horizontally.
Floor area – In relation to a building means the area bounded by the inner finished surfaces of the enclosing walls, or, on any side where there is no enclosing wall, by the outermost edge of the floor on that side and in calculating the area of a building or part of a building there shall be included in such area the space occupied by any walls, shafts, ducts or structure within the area being measured (see Diagram C1 of Appendix C).
Gallery – Is a floor or storey which consists of a raised area or platform which projects into the space of the room, providing extra floor area.
Habitable room – A room used for living or sleeping purposes but does not include a kitchen having a floor area less than 6.5 m2, a bathroom, toilet or shower room.
Hydrant – an assembly comprising a valve and outlet connection from an external fire mains, provided to deliver a supply of water for fire-fighting.
Height (of a building or storey) - (or of part of a building which is completely separated throughout, both below and above ground, by a compartment wall or compartment walls in the same continuous vertical plane) means the height of such building or part measured from the mean level of the ground adjoining the outside of the external wall of the building to the level of half the vertical height of the roof of the building or part, or to the top of the walls or of the parapet (if any), whichever is the higher (see Diagram C5 of Appendix C).
Inner room – A room from which escape is possible only by passing through an access room.
Means of escape – Physical means where by a safe route or routes is or are provided for persons to travel from any point in a building to a place of safety.
Measurement - (For area, cubic capacity, height of a building and number of storeys) - See Appendix C, Diagrams C1 to C5.
Notional boundary – A boundary presumed to exist between buildings on the same site (see Diagram 14).
Place of Safety – A place, normally in the open air at ground level, in which persons are in no danger from fire.
Pipe – Includes: pipe fittings and accessories; excludes: a flue pipe and a pipe used for ventilating purposes (other than a ventilating pipe for an above ground drainage system).
Protected corridor/lobby – A corridor or lobby which is adequately protected from fire in adjoining accommodation by fire-resisting construction.
Protected stairway – A stairway which is adequately protected from fire in the accommodation through which it passes by fire-resisting construction and discharges through a final exit to a place of safety.
Relevant boundary – The boundary which the side of the building faces (see Diagram 15). A notional boundary can be a relevant boundary.
Rooflight – Any domelight, lantern light, skylight or other element intended to admit daylight through a roof.
Storey – means any of the parts into which a dwelling house is divided horizontally above or below ground level including a gallery but excluding any part of a dwelling house situated above the level of the roof space which has not been adapted to be used for habitable purposes.
Thermo-plastic material - See Appendix A, paragraph A16.
Unprotected area - In relation to a side or external wall of a building means:
a window, door or other opening; and
any part of the external wall which has less than the relevant fire resistance set out in Section 4.4; and
any part of the external wall which has combustible material more than 1 mm thick attached or applied to its external face, whether for cladding or any other purpose (combustible material in this context is any material that is not included in Tables A6 or A7 in Appendix A).
Wall - (for the purpose of S4) includes:
the surface of glazing (except glazing in doors),and
any part of a ceiling which slopes at an angle of 70° or more to the horizontal.
but a wall excludes (for the purpose of S4):
doors and door frames;
window frames and frames in which glazing is fitted;
architraves, cover moulds, picture rails, skirtings and similar narrow members; and
fireplace surrounds, mantle-shelves and fitted furniture.