Building standards technical handbook 2019: non-domestic

Life safety is the paramount objective of fire safety. Non-domestic buildings should be designed and constructed in such a way that the risk of fire is reduced and if a fire does occur, there are measures in place to restrict the growth of fire and smoke to enable the occupants to escape safely and fire-fighters to deal with fire safely and effectively.

There are more than 2000 reported fires in non-domestic buildings every year in Scotland. The most common cause of accidental fires in non-domestic buildings is faulty appliances, accounting for more than 20% of fires followed by cooking at around 16%. Statistics also show that around 24% of fires in non-domestic buildings are deliberately started. While the number of deaths from fires in non-domestic buildings is less than domestic buildings the potential for significant life loss and injuries is far greater. This is due to large occupancy capacities, building complexity, occupant capability and behaviour including the potential for delay in occupant evacuation following the outbreak of fire.

In the event of an outbreak of fire, it is important that the occupants are warned as soon as possible. The guidance to Standard 2.11 provides recommendations for the installation of alarm and detection systems in buildings where people may be asleep or where there is a particularly high risk.

The standards and guidance in this section are designed to work together to provide a balanced approach to fire safety. The building elements, materials, components or other parts of the building identified in the guidance should follow the appropriate performance levels that are recommended throughout the guidance. However where an element, material, component, or other part of a building is covered by more than one standard, the more demanding guidance should be followed in most cases.

The purpose of the guidance in Section 2 is to achieve the following objectives in the case of an outbreak of fire within the building:

Protection of life - it is important to recognise that the standards will not guarantee the life safety of all building occupants. Occupants in buildings do not normally perceive themselves to be at risk from fire and are not usually aware of the speed that fire can spread. The risk to occupants is greater if they are asleep during the outbreak of fire as they are likely to be roused more slowly. Occupants should be warned as soon as possible following the outbreak of fire and the guidance to Standard 2.11 provides recommendations for the installation of alarm and detection systems in non-domestic buildings.

Fire and rescue service - in some cases, occupants will not react quickly enough before being overcome by the effects of the fire and smoke and as a result, may require to be rescued by the fire and rescue service. For facilities to assist the fire and rescue service, see Standards 2.12 to 2.14.

Sustainability - the building regulations are primarily concerned with the protection of people from the dangers inherent in buildings, rather than protecting the owners of buildings from any economic loss which might occur. However following the guidance in the handbook will continue to embed active and passive fire protection systems within buildings which should reduce the likelyhood of the total destruction of the building following the outbreak of fire.

Guidance in this section may not be appropriate for the following buildings as they are rarely designed and constructed in Scotland:

In such cases, the alternative approach as described in clause 2.0.7 should be followed.

In the case of a mixed use building containing non-domestic and domestic accommodation, reference should be made to the Technical Handbook for domestic buildings as well as the guidance contained in this Handbook.

The rules of measurement in Section 0 of the Technical Handbook may not be appropriate for the guidance in Section 2 Fire. For example, to establish the height of the topmost storey for fire and rescue service facilities, the height should be measured from the fire and rescue service access level and not necessarily the lowest ground level. Therefore, methods of measurement unique to fire are described within the guidance under each of the relevant standards.

The following guidance on measurements are unique to Section 2 Fire of the Handbooks and where appropriate, should be read in conjunction with the measurements specified in schedule 4 to regulation 7 as set out in Section 0 General.

Plant storeys - for the purpose of measuring the height above ground to the top most storey of a building, roof-top plant areas and any top storeys consisting solely of plant rooms, should be excluded.

An openwork floor is a floor with an open mesh decking which allows smoke to pass through. It is common to construct multi-level openwork floors around high bay racking systems. In such cases, the total storey area should be taken to be the total area of all openwork floors within that storey, including the floor area taken up by the racking system. Therefore, each level should be measured independently to the innermost surface of the enclosing walls and then added together to give the total storey area.

The area of:

The key changes that have been made to the standards and guidance since 1 October 2019.

Buildings accessible to the general public is intended to include buildings where members of the public can enter during normal opening hours and are allowed to access all parts of the building, other than those parts restricted to staff only.

Protected routes of escape - throughout the document there are references to protected routes of escape these include: escape routes in a central core, fire and smoke control in corridors, flat roofs, access decks, galleries with rooms enclosed below, openings in floors, places of special fire risk, protected lobbies, protected zones, rooms, toilets and washrooms in protected zones, external escape stairs, escape stairs in basements and auditoria. This list is not exhaustive and is not intended to cover all parts of a building providing protected routes of escape. For example, compartment walls and compartment floors also protect routes of escape but are covered by the guidance to Standard 2.1.

External areas - a roof, an external balcony, or an enclosed courtyard open to the external air, where the area is more than 8m² and to which there is access for a purpose other than maintenance, should be regarded as a room.

Circulation areas in non-domestic buildings include unprotected zones or areas in a room or space which provide access to an exit and may be permanently demarcated from any space intended for human occupation.

Alternative means of complying with building standards – the guidance contained within this Technical Handbook indicates one or sometimes more than one means of complying with the mandatory building standards 2.1 to 2.15. In the majority of projects it is envisaged that meeting the guidance will be the usual means of showing that compliance with the building standards has been achieved.

However, it should be appreciated that, due to the generic nature of the guidance it cannot cover all building designs or, for example, innovative or new methods of construction. In such cases the designer or engineer will be required to show, by alternative means, that compliance with the building standards will be achieved in the completed building. For example, where the elements of structure are engineered timber (including cross laminated timber), the structure should maintain stability during the fire growth and fully developed post flashover phases of the fire without reliance on intervention from the fire and rescue services. Encapsulation of combustible elements of structure may require to be provided to protect the structure against ignition and charring for the duration of the fire. Where encapsulation (i.e. both physically and in terms of the period of fire resistance duration) is not provided or does not protect the combustible material against ignition and charring for the duration of the fire, the structural fire engineer should consider the additional contribution of the exposed combustible material to the fire load density including an assessment of the structural stability of the building due to both potential delamination and failure of the fixings at elevated temperatures.

Fire safety engineering - it is reasonable to demonstrate compliance with the functional standards by alternative means and in such cases, the fire engineer, the building standards verifier and the fire and rescue service should be consulted early in the design process.

Fire safety engineering may be the only practical way to achieve a satisfactory level of fire safety in some large and complex buildings or where innovative or new methods of construction are used. In such cases a holistic approach is desirable from first principles rather than following, in part or wholly, the guidance contained in the Technical Handbooks. In such cases the building standards verifier and the fire and rescue service should be consulted as part of the Qualitative Design Review (QDR) process.

For many projects it is likely that designers will follow the guidance in the Technical Handbooks and fire engineering techniques will not be necessary. In its simplest form the QDR team may define the acceptance criteria in terms of compliance with the Handbooks.

However, it is common for fire engineers and regulators to be engaged relatively late in the design process to resolve fire safety issues raised during the verification or, in extreme cases, the construction process. This is unhelpful as fire engineers are often commissioned to resolve specific issues where the design does not follow the guidance rather than assessing the building holistically. This can lead to a comparative exercise against unrealistic worse case scenarios of a “code compliant” design to justify deviations. This is not the intent of the guidance and it is important that the safety goals are well defined and achieved with a sufficient margin of safety. The objective of a comparative study should be to demonstrate that the building design, as a whole, presents no greater risk to the occupants than a similar type of building designed in accordance with the Technical Handbook guidance. Further, it is common for the inappropriate use of Computational Fluid Dynamics where the deviations from the Handbooks would not merit such an exercise to be carried out. It is recognised that there may be instances where small deviations from the guidance do not warrant a “whole building” fire engineered design and inevitably involves a degree of negotiation without the need for detailed analysis.

Not all cases of variance from the guidance will require the appointment of a fire engineer. Reference could be made to ‘A simplified approach to alternative fire safety strategies’ Scottish Government (2010), which provides additional advice.

Existing buildings - it may be appropriate to vary the guidance contained in this Handbook when assessing the guidance against the constraints in existing buildings, especially those buildings which are listed in terms of their architectural or historic interest. In such cases, it would be appropriate to take into account a range of fire safety features, some of which are dealt with in this Handbook and some of which are not addressed in any detail. For more detailed information, guidance is contained in the ‘Guide for Practitioners 6 – Conversion of traditional buildings’ (Historic Scotland).

Fire engineering designs can be complex and many require extensive use of engineering judgement. The following documents are cited to ensure that the guidance given encompasses best practice worldwide:

The use of either document assumes that those carrying out or assessing a fire engineering approach have sufficient technical training, knowledge and experience to understand fully the risks involved.

The objectives of any fire safety strategy should be established first and designers and verifiers should be aware of the importance of the design assumptions. For example, the strategy should include an assessment of the system reliability. This will help to ensure that the fire safety objectives have been met.

Responsible person - it is important that owners/responsible person understand that the fire safety measures installed in a building need to be maintained and tested over the life time of the building so that they will operate effectively. BS 7974 and IFEG assume that all aspects of the fire engineering strategy are capable of being maintained and deployed over the lifetime of the building. If for example, alterations are found to be necessary due to changes to the building layout, the original strategy may need to be re-evaluated to ensure the fire safety provisions have not been compromised. For this reason, the fire strategy should preferably support any fire safety risk assessment required under Part 3 of the Fire (Scotland) Act 2005, as amended.

Fire safety engineering involves the use of scientific based calculations and/or statistical information to demonstrate an adequate level of safety for a specific building, structure or installation. In this regard the fire safety strategy is based on performance rather than prescription. Therefore, fire safety engineering is about the need to identify the fire hazard, assess the fire risks, understand the consequences and to offer fire safety strategies and designs to show how the objectives have been met. The ‘tools’ that support fire engineering can include calculation methods, which are used to demonstrate that under a worst reasonable case, tenable conditions are maintained during the evacuation period. For example, a smoke exhaust fan in a smoke reservoir within an atrium space fails to operate but the smoke layer height continues to be maintained by the activation of a stand-by fan.

It is recognised that fire engineering is still a rapidly developing field and as such does not have the standardised codes for approaching and solving problems compared to other engineering disciplines. The documents identified above aim to provide a structured framework for assessing the interaction between, buildings, people and fire, and to facilitate innovation in design without compromising safety. They provide information on how to undertake a detailed analysis of specific aspects of fire safety engineering in buildings.

In practice, both frameworks provide a flexible but formalised engineering approach to fire safety which can be applied to new or existing buildings to show that the functional standards have been met.

BS 7974: 2019 Application of fire safety engineering principles to the design of buildings is supported by 7 published documents:

International Fire Engineering Guidelines (IFEG) have been developed for use in the fire engineering design and approval of buildings. The objectives of the guidelines are to provide:

The IFEG sub-systems bear a very close resemblance to the subsystems used in BS: 7974: 2019 and are set out below:

Clause 1.3.2 of IFEG states that “Typically, each building project is unique and similarly, each fire engineering evaluation is unique". It is not sensible, therefore, to set down detailed guidance on how the fire safety analysis should be undertaken. Instead, it is the responsibility of the fire engineer to plan the analysis for the particular project, based on the decisions taken during the preparation of the fire engineering brief as discussed in Chapter 1.2.

Places of lawful detention for example prisons, secure accommodation and mental health premises, present particular problems owing to the obvious difficulties of providing both the level of security required and effective means of evacuation in the event of fire. Due to the constraints this can place on the design it may be necessary to vary from the guidance contained in this section of the Technical Handbook. In some cases it may be necessary to use fire safety engineering as part of such an alternative approach having evaluated the full range of fire safety features proposed to control the risk and the potential consequences of a fire.

It is important to be aware that there is other legislation, apart from building regulations, imposing requirements for means of escape in case of fire and other fire safety measures. It is therefore recommended that consultation with those responsible for such legislation takes place before the application for building warrant is finalised. Any necessary fire safety measures requiring building work can then be included in the application.

Part 3 of the Fire (Scotland) Act 2005 (2005 Act), as amended introduced a fire safety regime which applies to non-domestic buildings. The regime does not generally apply to domestic buildings but may apply where staff are employed or members of the general public have access e.g. a dental surgery within a dwelling. The regime will also apply to domestic buildings which are licensed as Houses in Multiple Occupation and to some domestic buildings where certain care services are provided. Those domestic premises covered by Part 3 of the 2005 Act are defined in section 78 of the Act.

Persons with obligations under the Act are required to carry out a fire safety risk assessment which may require additional fire safety precautions to reduce the risk to life in case of fire. For example, measures to reduce the risk and spread of fire, means of escape, fire-fighting equipment, fire detection and warning, instruction and training. Other measures are prescribed by regulation. The fire safety risk assessment should be kept under continuous review.

There is (sector specific) guidance for various building types on how to comply with Part 3 of the Act on the firelaw website.

In many premises, existing fire safety measures have been incorporated in accordance with building regulations however it is possible for a higher standard to be applied as a consequence of a fire safety risk assessment.

Section 71 of the 2005 Act makes it clear that terms, conditions or restrictions in licences, including statutory certification or registration schemes, are to have no effect if they relate to fire safety requirements or prohibitions which are or could be imposed under Part 3 of the 2005 Act.

The Fire Safety (Scotland) Regulations 2006 made under the Fire (Scotland) Act 2005 contain provisions which are part of the fire safety regime. These regulations must be considered along with Part 3 of the 2005 Act. The regulations contain further requirements in respect of fire safety risk assessment and obligations of duty holders.

Section 70 of the Fire (Scotland) Act 2005 restricts the application of Part 1 of the Health and Safety at Work Act 1974 and any regulations or orders made under it in relation to general fire safety. There are exceptions; firstly where a single enforcing authority enforces both pieces of legislation and secondly, in respect of sites where the Control of Major Accident Hazards Regulations 1999 (COMAH) apply.

The Management of Health and Safety at Work Regulations 1999 require all employers to assess the risks to workers and any others who may be affected by their work or business. The objective is to identify preventative and protective measures and implement corrective action as appropriate. However in general, these regulations do not apply to general fire safety by virtue of the restriction in section 70 of the Fire (Scotland) 2005 Act.

The Health and Safety (Safety Signs and Signals) Regulations 1996 impose requirements in relation to fire exit and directional signs. In addition, the Fire (Scotland) Regulations 2006 requires emergency routes and exits to be indicated by signs. Advice on fire safety signs is given in the HSE publication, ‘Safety signs and signals: Guidance on Regulations – The Health and Safety (Safety Signs and Signals) Regulations 1996’. Guidance is also available in BS ISO 3864-1-2011 and BS 5499: Part 4: 2013 on graphical symbols, fire safety signs and escape route signing.

The Construction (Design and Management) Regulations 2015 is intended to protect people working in construction and others who may be affected by their activities. The regulations require the systematic management of projects from concept to completion and throughout the life cycle of the structure, including eventual demolition. The CDM Regulations require designers and those who control or carry out construction work to identify hazards associated with their designs or work (including risk from fire) and plan to eliminate, reduce or control the risks.

Dangerous Substances and Explosive Atmospheres Regulations 2002 require the risks from substances with flammable, explosive or oxidising properties to be properly controlled. This can include particular requirements in respect of design and construction in which substances are present or in the vicinity. The regulations are enforced by the HSE, or for certain types of premises, the local authority. In general, these regulations do not apply to general fire safety as a result of similar provisions being imposed by the Fire Safety (Scotland) Regulations 2006.

Sports Grounds - When designing or verifying sports grounds, it is appropriate to use the guide to Safety at Sports Grounds http://www.culture.gov.uk/. The guide has no statutory force but many of its recommendations will be given force of law at individual grounds by their inclusion in safety certificates issued under the Safety of Sports Grounds Act 2011 or the Fire Safety and Safety of Places of Sport Act 1987.

The Safety of Sports Grounds Act 1975 is amended by Article 7 of the Fire (Scotland) Act 2005 (Consequential Modifications and Savings) Order 2006 so that a condition of a safety certificate for a sports ground may not require a person to contravene Part 3 of the 2005 Act or regulations made under it and requires the local authority to amend such a certificate if it would have that effect.

The Fire Safety and Places of Sports Act 1987 is amended by Article 13 of the Fire (Scotland) Act 2005 (Consequential Modifications and Savings) Order 2006 so that a condition of a safety certificate for a regulated stand may not require a person to contravene Part 3 of the 2005 Act or regulations made under it and requires the local authority to amend such a certificate if it would have that effect.

The Civic Government (Scotland) Act 1982 contains provisions for public entertainment licences. Similarly to liquor licences, the appropriate bodies are consulted before a licence is granted. The Act has been amended by the Fire (Scotland) Act 2005 (Consequential Modifications and Savings) Order 2006 to prevent fire safety conditions being imposed where Part 3 of the Fire (Scotland) Act 2005, as amended applies.

Houses in Multiple Occupation (HMOs) - The domestic Technical Handbook should be used for HMOs that are dwellings and flatted student accommodation that are essentially designed as self-contained flats, including cluster flats, regardless of the evacuation strategy. The non-domestic Technical Handbook should be used for all other HMOs and student accommodation designed on the traditional "halls of residence" principle. It should be noted that HMOs may also require to be licensed under the Civic Government (Scotland) Act 1982 (Licence of House in Multiple Occupation) - Order 2000 as amended. To be classified as a house in multiple occupation, the accommodation must be the only or principal residence of 3 or more people from different families. In relation to fire safety aspects, HMOs which require a licence are also subject to Part 3 of the Fire (Scotland) Act 2005, as amended and guidance is available on the firelaw website.

The Care Inspectorate is responsible for regulating a diverse range of care services some of which are delivered in non-domestic buildings (e.g. care homes, nurseries, independent hospitals, hospices, residential schools and secure accommodation) and some in domestic buildings (e.g. childminding, supported accommodation and adult placement services). The services are inspected by the Inspectorate against national care standards issued by Scottish Ministers some of which include physical standards for the premises. The Inspectorate consults with the fire and rescue service on fire safety matters as part of the care service registration process. Where the applicant for a warrant intends to use or provide such a service, they should consult the Inspectorate and fire and rescue service for advice.

2.A - Additional guidance for residential care buildings

2.B - Additional guidance for hospitals

2.C - Additional guidance for enclosed shopping centres

Certain types of buildings pose particular risks and require particular solutions. Additional guidance for three specific building types are grouped in three annexes; residential care buildings in annex 2.A; hospitals in annex 2.B and enclosed shopping centres in annex 2.C. Where an enclosed shopping centre has a mall on 3 storeys or more, the alternative approach described in clause 2.0.7 should be used.

The intention is to help designers and verifiers find the information they require quickly when designing or vetting such buildings. However it is important to remember that the guidance in the annexes is in addition and supplementary to the guidance to Standard 2.1 to 2.15.

Annex 2.D: Resistance to fire

Resistance to fire is expressed in terms of fire resistance duration and reference throughout this document to a short, medium or long fire resistance duration, are explained in annex 2.D. The performance levels include properties such as loadbearing capacity, integrity and insulation.

Annex 2.E: Reaction to fire

Reaction to fire of construction products is expressed as European Classification A1, A2, B, C and D and explained in annex 2.E. The performance levels include properties such as the ease of ignition and the rate at which the product gives off heat when burning. When reference is made to European Classification A2, B, C and D throughout this Handbook, the performance criteria should be read as including sub-indices “s3, d2”. This means there is no limit set for smoke production (s3) and/or flaming droplets/particles (d2).

Annex 2.F: Vulnerability of roof coverings

Roof coverings are expressed in terms of low, medium or high vulnerability and explained in annex 2.F. The performance levels relate to the capability of a roof to resist penetration from fire and flame spread when the external surface is exposed to radiation and flames.

Certification - Scottish Ministers can, under Section 7 of the Building (Scotland) Act 2003, approve schemes for the certification of design or construction for compliance with the mandatory functional standards. Such schemes are approved on the basis that the procedures adopted by the scheme will take account of the need to co-ordinate the work of various designers and specialist contractors. Individuals approved to provide certification services under the scheme are assessed to ensure that they have the qualifications, skills and experience required to certify compliance for the work covered by the scope of the scheme. Checking procedures adopted by Approved Certifiers will deliver design or installation reliability in accordance with legislation.

Third party accreditation - Since the performance of a system, product, component or structure is dependent upon satisfactory site installation, testing and maintenance, independent schemes of certification and accreditation of installers and maintenance firms of such will provide confidence in the appropriate standard of workmanship being provided.

Confidence that the required level of performance can be achieved will be demonstrated by the use of a system, material, product or structure which is provided under the arrangements of a product conformity certification scheme and an accreditation of installers scheme. Third party accredited product conformity certification schemes not only provide a means of identifying materials and designs of systems, products or structures which have demonstrated that they have the requisite performance in fire, but additionally provide confidence that the systems, materials, products or structures actually supplied are provided to the same specification or design as that tested/assessed.

Third party accreditation of installers of systems, materials, products or structures provides a means of ensuring that installations have been conducted by knowledgeable contractors to appropriate standards, thereby increasing the reliability of the anticipated performance in fire.

Local authority verifiers may accept the certification of products, components, materials or structures under such schemes as evidence of compliance with the relevant standard. Similarly, local authority verifiers may accept the certification of the installation or maintenance of products, components, materials or structures under such schemes as evidence of compliance with the relevant standard. Nonetheless, a local authority verifier may wish to establish, in advance of the work, that any such scheme is adequate for the purposes of the Building Regulations.

Many certification bodies which approve such schemes are accredited by UKAS.