Essential need-know facts about Parts A to P of the Building Regs

Part A: Structure

This regulation covers the strength and stability of buildings. It provides guidance on the design, construction and alteration of cladding, roofing, structure and the foundations of buildings. The Approved Document, which gives technical details of how to comply with the rules, is split into three sections

  • A1 Loading which provides guidance to ensure that the weight of the building and additional loads imposed including snow and wind are transmitted to the ground, without affecting adjacent buildings.
  • A2 Ground movement gives guidance on dealing with swelling or shrinkage of the subsoil and subsidence.
  • A3 Disproportionate collapse. Explains how a building must be constructed so that it does not collapse to an extent disproportionate to the cause. For example if a building is hit by a vehicle then its failure should be no more than is proportionate to the vehicle’s impact.

Last updated: 2004
Revision due: 2013

Part B Fire Safety

Means of escape, internal and external fire spread and fire service access are all covered in this document. Its aim is to ensure occupants can escape from a building unaided; in addition it also gives guidance on how to assist fire fighters to save lives.

The document is in two parts: Volume 1 deals with dwellings, Volume 2 deals with all other types of buildings including offices, public buildings, multi-story and industrial buildings as well as flats. Both volumes cover the same five topic areas:

  • B1 Means of warning and escape: gives guidance on fire alarms and fire detection, escape routes and staircases,
  • B2 Prevention of fire spreading through internal surfaces and linings: deals with internal finishes
  • B3 Prevention of fire spread internally through premature structural collapse: provides guidance to ensure the building’s structure is suitably protected and that fire does not spread through cavities in walls and partitions. It also deals with the subdivision of a building into fire compartments.
  • B4 Prevention external fire spread: explains the rules on controlling the space between buildings. It also gives information on suitable roof coverings to help limit the spread of fire.
  • B5 Access and facilities for the fire service: provides details of suitable access roads and the provision of fire mains and hydrants

Last updated: December 2006 (amended 2010)
Revision due: After 2013


Part C: Site Preparation and resistance to moisture

The approved document is in two sections:

  • C1 Deals with ground contaminants and pollution. It includes guidance on dealing with vegetation, contaminated soil and hardcore containing sulphate that might damage the building. It also explains how to deal with noxious gases such as radon or methane that could be a danger to public health.
  • C2 Deals with protection of the building and its inhabitants from moisture. This includes advice on dealing with groundwater and the provision of subsoil drainage, gives guidance on suitable ground floor construction, the design of walls to protect against both groundwater and precipitation along with advice on suitable construction for the junction between walls and windows. It gives advice on roof design and guidance on avoiding interstitial and surface condensation for both walls and roofs. It also gives advice on the design of floors in bathrooms and kitchens where there is the possibility of water spillage from baths and sinks.

Last updated: 2004
Revision due: 2013


Part D Toxic Substances

This is a short document. It was introduced to provide advice on precautions to prevent toxic fumes from cavity wall insulation affecting the health of a building’s occupants. In particular it makes reference preventing the fumes from urea-formaldehyde foam cavity-wall insulation penetrating the building.

Last updated: 2002

Revision due: after 2013

Part E Resistance to the passage of sound

This regulation deals with preventing the passage of sound within houses and flats as well as from adjacent dwellings. It also includes sound insulation requirements for new schools. The approved document is split into four sections

  • E1 Protection against sound from other parts of the building and adjoining buildings: Gives advice on how to design to protect against sound from other parts of the same building in the case of flats and sounds from adjoining buildings.
  • E2 Protection against sound within a dwelling-house etc: deals with protection against sound within the home. It includes advice on the resistance of internal walls and partitions to the passage of sound and guidance on limiting sound transmission between a bedroom and other areas of a house; and sounds from a WC to other habitable rooms. It also includes details on providing resistance to sound transmission between floors for both airborne and impact sound transmission. The document explains that pre-completion sound tests are required for all flats and dwellings unless robust details approach is adopted.
  • E3 Reverberation in the common internal parts of buildings containing flats or rooms for residential purposes: provides guidance on the prevention of reverberation sound such as footsteps in corridors and stairwells and entrance halls in blocks of flats and student accommodation
  • E4 Acoustic conditions in schools: guidance to ensure the acoustic conditions in classrooms and corridors of schools are “appropriate to the space’s intended use”.

Last updated: 2003 (amended 2004)
Revision due: 2013


Part F Ventilation

Ventilation is required to provide outside air for breathing, to remove airborne pollutants and odours and to control humidity to prevent moulds forming. The Document covers all building types including dwellings. In addition it provides guidance on the ventilation of car parks.

The Approved Document explains that there are two types of ventilation that affect buildings: purpose-provided ventilation and infiltration through air-gaps in the building’s structure. It recommends methods of achieving purpose provided ventilation, Air-tightness measures are covered in Part L of the Regulations. Air is also needed for combustion in heating boilers, but this is covered in Part J.

The Document also provides details on standards for ventilation and air quality including guidance on the rate of exhaust of stale air and the introduction of fresh, outside air into buildings. It explains the strategy of extracting air from areas with high levels of water vapour and from rooms with high levels of airborne pollutants such as photocopying rooms. 

For new and existing dwellings guidance is given on three ways of complying with the ventilation regulations. For offices the document provides guidance on four ways a design could comply with the rules. While for buildings other than offices including hospitals, hotels and laboratories it points designers to the relevant specialist guidance documents for ventilation rates.

The document also covers the requirement for the installation and commissioning of ventilation systems.

Last updated: May 2010
Revision due: Comes into effect October 2010; next revision due 2013


Part G Sanitation, hot water safety and water efficiency

The document deals with the provision of sanitary and washing facilities for all buildings including dwellings. It is in six parts:

  • G1 Cold water supply. This deals with the supply of drinking water and the supply of water to appliances including guidance on alternative sources of water including rainwater harvesting and the use of greywater. 
  • G2 Water efficiency. This gives details of permitted maximum quantity of water per person per day for dwellings and explains the method of calculation for estimated water consumption and process of notification to building control bodies. 
  • G3 Hot water supply and systems. Gives guidance on hot water heating and storage systems along with details of the maximum temperature of hot water for different applications and in designing to eliminate Legionnaires’ Disease.  
  • G4 Sanitary conveniences and washing facilities. Provides guidance on the number of sanitary appliances required and their appropriate layout and drainage. It also provides guidance on chemical and composting toilets.
  • G5 Bathrooms. This section deals with scale and provision of sanitary appliances for residential properties or buildings containing rooms for residential use and their discharge to drains.
  • G6 Kitchens and food preparation areas. This gives guidance on the provision of a suitable sink for restaurants and kitchens and on their discharge to drains.

Last updated: April 2010
Revision due: after 2013


Part H Drainage and waste disposal

This section deals with the design of above and below ground drainage, cesspools and tanks, rainwater drainage and refuse stores. It also deals with sewage infrastructure and the adoption of sewers.

The Approved Document is in six parts:

  • H1 Foul water drainage: Covers pipe size and water trap details, design recommendations for branch discharge pipes and stacks. It also gives details on below ground drains and sewers including layout and pipe cover, design recommendations for rigid and flexible pipes, pipe sizes and gradients and provision for clearing blockages and the siting of access points. In addition it gives information on the adoption of sewers and connection to public sewers
  • H2 Wastewater treatment systems and cesspools: Provides guidance on the design cesspools and other wastewater systems including their capacity, siting, construction and maintenance along with guidance on greywater and rainwater storage tanks.
  • H3 Rainwater drainage: Provides guidance on drainage from roofs including: gutter sizes, outlet sizes and materials suitable for use above ground, pipe sizes. It also provides guidance on the surface water drainage and the drainable of paved areas.
  • H4 Gives guidance on building over sewers
  • H5 Separate systems of drainage: Gives details on the requirements for separate rainwater and foul water drainage
  • H6 Solid waste storage: Details refuse storage for both domestic and non-domestic buildings including storage capacity and location.

Last updated: 2002
Revision due: 2013


Part J Combustion appliances and fuel storage systems

Part J deals the installation of boilers, chimneys and flues along with fuel storage. It applies to gas appliances up to 70kW and oil and solid fuel appliances up to 45kW – for larger appliances designers are referred to CIBSE guidance. The document is in six parts

  • J1 Air supply for combustion including guidance on the use of open flued appliances in very airtight houses.
  • J2 Discharge of products of combustion including guidance on the design and location of flues and chimneys
  • J3 Protection of building – provides guidance on the size and design of flues to ensure the safety of a building and its occupants from fires and fumes 
  • J4 Explains the rules on the provision of information on the performance capabilitiesof a flue or fireplace.
  • J5 Protection of liquid fuel storage systems provides guidance on minimising the risk of the fuel igniting in the case of fire in an adjacent building.
  • J6 Protection against pollution from failure of fuel storage tanks including guidance on where the secondary containment of oil systems are necessary

Last updated: May 2010
Revision due:  comes into effect October 2010


Part K Protection from falling, collision and impact

This section of the Regulations covers the design of stairs, ramps and guardrails to prevent falling; in addition it deals with protection from collision with open windows, skylights and ventilators and impact from doors. The Approved Document provides guidance on:

  • The design of stairways, including private and institutional and assembly stairs and stairs for loft conversions
  • The design of ramps
  • Provision of landings on stairways and ramps
  • The provision of handrails and guards
  • Headroom and width recommendations for stairs
  • Protection from falling from stairways, ramps, balconies, roofs and lightwells
  • The design of vehicle barriers and loading bays to protect people
  • The design of windows and use of protection to prevent people walking into open windows
  • The safe design of doors

Last updated: 2000
Revision due: 2013


Part L Conservation of fuel and power

Part L is a key part of the government’s strategy to achieve zero carbon buildings by 2016-2019. It addresses energy efficiency from building design through to implementation. Recent changes to the Document have focused on closing the gap between the designers’ expectation of performance and the building’s actual performance.

The Approved Document is split into four parts:

  • L1A Conservation of fuel and power (new dwellings)
  • L1B Conservation of fuel and power (existing dwellings)
  • L2A Conservation of fuel and power (new buildings other than dwellings)
  • L2B Conservation of fuel and power (existing buildings other than dwellings)

The documents

  • Set out the energy efficiency requirements for dwellings and buildings and outline the methodology to demonstrate compliance with these requirements.
  • Outline what supporting information should be provided to building control to enable the body to understand the key features of a design’s Part L compliance strategy
  • Sets out carbon emission targets
  • Gives minimum U-values for building elements and minimum efficiencies for heating appliances
  • Provides guidance to ensure the design intent is realised through various means including pressure testing of a building’s air permeability and limiting thermal bridging of the building envelope, including the use of accredited construction details
  • Outline the new rules on commissioning of building services and the provision of operating and maintenance instructions
  • Provides details on limiting solar gains for non-domestic buildings

Last updated: May 2010
Revision due:  comes into effect October 2010, next revision due 2013


Part M Access to and use of buildings

Part M provides details on inclusive access to buildings and dwellings, sanitary accommodation and audience and spectator seating including those for disabled people. The Approved Document provides guidance on:

  • The design of approaches to buildings and dwellings
  • Provides guidance on access into buildings and dwellings, including the design of ramps and the design of entrance doors and lobbies
  • Provides guidance on design for access within a building, including the design of corridors and internal lobbies, ramps and internal circulation routes
  • Advises on lift design
  • Makes recommendations on access to facilities within a building including bars and restaurants, hotel bedrooms, shower and changing facilities
  • Offers advice on the number and design of sanitary conveniences
  • Makes recommendations for the design of audience and spectator seating
  • Advises on the location for accessible switches and socket outlets within a dwelling

Note: this document should be read in conjunction with the Disability Discrimination Act documents, which impose legally binding duties on building owners for access for disabled people.

Last updated: 2004
Revision due: 2013


Part N Glazing – Safety in relation to impact, opening and cleaning

This covers the safety of glazing, access for cleaning windows and measures to reduce the risk of people colliding with glazing. The Approved Document:

  • Gives guidance on which glazed areas that need protection from impact
  • Lists the glazing types that meet the requirements
  • Describes ways of making large areas of glazing more apparent to occupants
  • Recommends the location of window and rooflight controls
  • Provides guidance on access for cleaning windows and rooflights

Last updated: 2000
Revision due: 2013


Part P Electrical Safety – Dwellings

This document gives guidance on the safe design of low voltage (less than 600 Volts) electrical installations in or attached to houses or flats including dwellings above business premises.

  • Provides guidance on when and when not to notify building control bodies of work on an electrical installation
  • Guidance on the inspection and testing of electrical installations to verify that they are safe and comply with the Building Regulations before handover
  • Guidance on the self certification and third party certification of an electrical installations,
  • Information about other legislation that will affect an electrical installation
  • Provides examples of electrical installation diagrams of the type of installations likely to be encountered in dwellings
  • Provides examples of the IEE model inspection and certification forms 
  • Provides guidance on the harmonised cable identification colours
  • Lists authorised competent self-certification schemes for electrical installation work to support the Document

Last updated: April 2006
Revision due: 2013