Essential guides: British Standards

BS9999: 2008 Code of practice for fire safety in the design management and use of buildings

This standard gives recommendations on the design, management and use of buildings for fire safety for all people in and around buildings. In addition to the fire safety of offices the document also covers the design of atriums, shopping centres, storagebuildings, car parks and manufacturing buildings that were previously dealt with in separate standards. It applies both to the design of new buildings and to alterations, extensions and changes of use of existing buildings, however, it does not apply to individual homes. The standard also provides guidance on the management of fire safety in a building throughout its life.

BS9999 adopts a more flexible, fire engineering approach to fire safety design than Approved Document B, which provides basic fire safety advice for most buildings.This alternative approach classifies buildings according to a risk profile based on occupancy, fire growth rate, ventilation, room height and whether or not sprinklers are installed to provide extra time and safety to people when escaping from fire. Where enhanced safety measures are included, BS9999 permits longer travel distances and reduced exit stair widths.

BS 9999 supersedes the entire BS 5588 series with the exception of BS558 part 1 which deals with apartments.

BS 8300: 2009 Design of buildings and their approaches to meet the needs of disabled people. Code of practice

This standard explains how the built environment can be designed to anticipate and overcome restrictions that prevent disabled people making full use of premises and their surroundings independently, or with help from a partner or assistant. It includes design of buildings to enable disabled people to escape in a fire or other emergency (see BS9999). It should be read in conjunction with Approved Document M.

BS8300 gives recommendations on the approach to buildings along with advice on car parking provision for disabled people, the design of setting-down points and garaging, along with access routes to and around all buildings. Once inside a building, the standard gives advice on the design of entrances and the interiors of new buildings to ensure access is suitable for all building users.

The following building types are covered by BS8300:

•  Transport and industrial buildings and their associated concourses and car parks
•  Administrative and commercial buildings including offices, banks, shops, and public service buildings
•  Health and welfare buildings, e.g. hospitals, health centres, surgeries and residential home
•  Refreshment, entertainment and recreation buildings, including cafés, public houses, theatres, conference buildings, swimming pools and sports buildings
•  Buildings for worship
•  Educational, cultural and scientific buildings, such as schools, universities, art galleries, libraries and exhibition buildings
•  Residential buildings, e.g. hotels, university halls of residence, nursing homes and prisons.
•  Access to dwellings

Structural standards

A suite of new British Standards for structural design based on European Standards has been launched. Called the Eurocodes, the documents are a set of standardised European design standards which provide a common approach to structural design across the EU. They are intended to remove potential barriers to trade that exist when countries have different design standards.

There are 10 Eurocodes made up of 58 parts that are due to be adopted in all EU Member states. In the UK they replace conflicting existing British Standards, which were withdrawn on 31 March 2010, when the Eurocodes came into effect.

From 1 April 2010, all publically funded projects must be designed to the Eurocodes. However, designers need to be aware that some of that standards that have been withdrawn are still referenced in the Building Regulations Approved Documents, particularly Approved Document A (Structure), which is not due for revision until 2013. As a consequence parts of the old standards, notably: BS6399, BS5268, BS5950, BS8110, BS8002, BS8004 and BS8118 will remain available from BSI but will no longer be updated, which means they may not necessarily be suitable for all aspects of structural design in the medium and long term.

Designers also need to be aware of the perils of mixing Eurocodes with the old British Standards and  the government has issued a warning to building control bodies to “beaware of the risk of designs inappropriately mixing new design standards based on the BS ENs and withdrawn BS design standards”.

For a more detailed information on the Structural Eurocodes see Jeremy Wells’article http://www.building.co.uk/story.asp?sectioncode=748&storycode=3161234

BS 6465 Sanitary installations

This standard is in 3 parts:

• Part 1: 2006 + Amendment 1:2009 gives recommendations on the design of sanitary facilities. It covers the recommended scale of provision of sanitary and associated appliances in new buildings and buildings undergoing major refurbishment. It also covers the recommended scale of provision of portable toilets. When this standard was launched it effectively doubled the number of toilets in a commercial building compared to the previous 1994 standard by linking toilet provision to the enhanced building design population density used for the design of fire escapes rather than the British Council of Offices Best Practice Design guide, which bases toilet provision on a ratio of 60% male, 60% female. This caused an outcry with developers in particular because of the increased floor area given over to toilet provision. Amendment 1 was issued in 2009 to rectify the situation.
• Part 2: 1996 outlinesthe spaces to be provided for the location, installation, use and maintenance of sanitary appliances within dwellings, places of work or public amenities.
• Part 3: 2006 gives recommendations on the selection, installation and maintenance of commonly used sanitary appliances in new and refurbished buildings. It also covers portable toilets used as supplementary sanitary facilities, for workplaces and events. It deals with hygiene, selection, installation and maintenance, including cleaning and general maintenance of all sanitary installation units including electrical items. It does not deal with the detailed provisions of water supply, sanitary pipework, or drainage.

This standard applies to private dwellings, residential and nursing homes for older people, workplaces, shops and shopping malls, petrol stations, schools, theatres, cinemas, exhibition centres, libraries, museums, hotels, restaurants, licensed pubs, nightclubs, sports facilities, public toilets and temporary toilets.

BS 5395 Stairs

This standard is in two parts:

• Part 1: 2010is a code of practice that gives recommendations for the design of stairs with straight flights, including landings and winders for all types of building and industrial walkways.
• Part 2: 1984gives recommendations for the design of helical and spiral stairs for all building types.

Note: industrial stair treads are covered in BS 4592: Industrial type flooring and stair treads

This standard provides recommendations on how to make stairs safe for all users. According to BSI, the most important aspects of stair design that affects the safety of users are the tread dimensions. Steps need to be wide enough to accommodate a significant portion of the user’s foot because research has shown that over-stepping a tread coupled with the type of material on the stair nosing, can lead to users slipping when descending a stair. If there are no suitable handrails, or the person cannot reach them in time, this slip can lead to a serious incident.

BS 5395-1 does not cover stairs that are not connected to a building, such as steps that form part of the surrounding landscape or those that lead up to a front door; ramps; ladders; steps within swimming pools and limited-use stairs such as those that provide access to a loft or basement.

BS EN 12056 Gravity drainage systems inside buildings

The standard covers all drainage systems which operate under gravity for all building types including dwellings, commercial, institutional and industrial buildings.

The standard is in five parts:

• Part 1: 2000 General performance requirements
• Part 2: 2000 Sanitary pipework, layout and calculation
• Part 3: 2000 Roof drainage, layout and calculation
• Part 4: 2000 Wastewater lifting plants, layout and calculation
• Part 5: 2000 Installation and testing, instructions for operation, maintenance and use

The two key areas covered by the standard are sanitary pipework within a building and roof drainage.

The design of sanitary pipework is covered in Part 2 of the standard, which sets out the principles to be followed for both layout and calculation. However, according to BSI it “makes limited provision for drainage systems conveying trade effluent and also for fluids removed by pumps”. It also outlines some of the different drainage systems in use within Europe.

Part 3 provides information on the design of rainwater drainage from roofs and paved areas. It also covers the choice of materials and inspection, testing and maintenance.

BS 6180 and BS 6206 – covers barriers in buildings including the performance of safety glass

The first of these standards, BS 6180: 1999 provides recommendations for the design and construction of temporary and permanent barriers in and about buildings as protection against falling and to restrict or control the movement of people or vehicles. This standard applies to barriers: that indicate routes; capable of stopping or diverting small slow-moving vehicles; walls, glazing and other elements of buildings or structures installed for protection.

This standard does not apply to barriers:

• For resisting impact from vehicles travelling at speeds greater than 16 km/h;
• Used in building works and engineering construction;
• Safety barriers for the protection of children up to 24 months.

The second standard, BS 6206: 1981 deals with the performance requirements and a test method for impact energy absorption for flat safety glass and safety plastics in buildings to reduce the risk of injuries caused by cutting and piercing in accidents where these materials are involved. However, the standard does not specify situations where safety glass and safety plastics should be used, nor does it specify requirements for their durability and whether the material should break safely or remain intact on impact.

BS 476 parts 6 & 7 Fire tests on building materials and structures and BS EN 13501 parts 1 and 2 Fire classification of construction products and building elements

BS 476 covers a whole range of fire tests but the sections of the standard that have been most contentious are the parts that deal with the fire properties of building materials and in particular the classification for surface spread of flame. Fire reaction tests determine whether a material will affect the severity of a fire in a building.

Historically, fire reaction tests for building products have been different across EU member states, with the result that a material accepted in for use in one state is not automatically approved in another. In the UK, products have been previously tested in accordance with BS476 parts 6 and 7 to measure properties such as the rate a material releases heat, its combustibility and the spread of flame along its surface.

The British Standard classifies materials as class 0, 1, 2, 3 or 4, with 0 being the best performer. However under the Construction Products Directive, BS EN 13501 was introduced to provide a standardised classification system for construction materials across all EU states based on radically different European fire test methods.

Under the European standard the best performing materials are classified A1, next comes A2, then B through to F. Because of the different test method used a material that achieves the highest British Standard rating for the surface spread of flame, Class 0, may not get an A1 under the European tests.  For example foil faced phenolic foam does well under the British Standard where it is Class 0, but less well under the European tests where it is classified C.