Building standards technical handbook 2022: non-domestic

Guidance on achieving the standards set in the Building (Scotland) Regulations 2004. This handbook applies to a building warrant submitted on or after 1 June 2022 and to building work which does not require a warrant commenced from that date.

4.8 Danger from accidents

Mandatory Standard

Standard 4.8

Every building must be designed and constructed in such a way that:

  1. people in and around the building are protected from injury that could result from fixed glazing, projections or moving elements on the building

  2. fixed glazing in the building is not vulnerable to breakage where there is the possibility of impact by people in and around the building

  3. both faces of a window and rooflight in a building are capable of being cleaned such that there will not be a threat to the cleaner from a fall resulting in severe injury

  4. a safe and secure means of access is provided to a roof, and

  5. manual controls for ventilation and for electrical fixtures can be operated safely.


Standard 4.8(d) does not apply to domestic buildings.

4.8.0 Introduction

This standard covers several unrelated safety issues that do not lend themselves to inclusion in other standards although glass and glazing do figure prominently.

Collision or entrapment accidents result in a significant numbers of deaths and injuries to people in and around buildings every year. The majority of these accidents occur during normal use and involve building features such as doors, windows and areas of fixed glazing, with the risk of injury increased where vulnerable glass is involved. Collisions with glazing are very common as it can, if transparent, be difficult to see and may create confusing lighting effects, presenting particular difficulties for a person with a visual or cognitive impairment.

Falls still result in deaths and serious injury to people while cleaning windows. Whether windows are cleaned professionally or by the building owner, provision should be made to permit glazing to be cleaned safely.

Where ventilation is provided by openable windows or rooflights, people may encounter difficulty and a hazard may arise in using these items where controls are poorly sited. Similarly, location of electrical sockets, switches and other controls can, if not considered, affect safe and convenient use.

Roof work continues to be an activity with a high accident rate. Almost 1 in 5 construction deaths occur in this sphere of work. Roof work therefore should be recognised as a high-risk activity and high safety standards should be actively promoted by all those who are involved. Casual roof access should be discouraged but where access is provided, such as for inspection and maintenance, this should ensure safe access, giving protection against falls. Use of fragile roof materials should be discouraged wherever possible.

Conversions - in the case of conversions, as specified in regulation 4, the building as converted shall meet the requirements of this standard in so far as is reasonably practicable, and in no case be worse than before the conversion (regulation 12, schedule 6).

4.8.1 Collision with projections

Fixtures that project into, or open onto any place to which people have access can be a hazard. Any element of a building capable of projecting into a circulation route or space should be positioned, secured or guarded so that it does not present a risk to building users.

The simple way to avoid risk is to ensure that obstructions do not encroach into such spaces. However where a building element does project into a circulation route or space, and any part of the obstruction is less than 2.0m above the ground, guarding should be provided to both highlight the hazard and prevent collision with the building element.

Guarding should be provided to:

  • any moveable projection, such as a door leaf or window frame, that opens across a circulation route or into a circulation space, or

  • any permanent projection of more than 100mm into a circulation route or space that begins at a height of more than 300mm above the ground, or the projection of which increases with height by more than 100mm, or

  • any accessible area where headroom reduces to less than 2.0m, such as beneath a stair flight.

Guarding should comprise of a continuous horizontal rail, at a height of between 900mm and 1.1m above ground level and a solid element, such as kerb upstand or rail, positioned approximately 100mm above ground level, to assist in detection by a visually impaired person using a cane.

There should be visual contrast between guarding rails and surrounding surfaces. Consideration should be given to positioning of guarding to direct a person away from the hazard, further reducing the risk of a collision.

Additional guarding may be needed to prevent collision with, or entrapment by, a powered door leaf (see clause 4.1.8).

4.8.2 Collision with glazing

Glazing in certain locations is more vulnerable to human impact. Care should be taken in the selection of glazing at low level in screens, walls and partitions or in areas surrounding doors, particularly where glazed side panels may be mistaken for doors.

To reduce the risk of injuries from accidental human impact in these locations, designers should either:

  • fit glazing of a type, thickness and pane size that will be resistant to impact, which either does not break or breaks safely, or

  • provide protection in the form of guarding to vulnerable glazing.

Glazing should be designed to resist human impact as set out in BS 6262: Part 4: 2005, where all, or part, of a pane is:

  • within 800mm of floor level, or

  • part of a door leaf, or

  • within 300mm of a door leaf and within 1.5m of floor level.

Glazing manifestation - large areas of transparent glazing, in fixed screens or partitions or where forming doors, can be difficult to identify and may be a particular hazard to a person with a visual impairment. Glazing in a building, positioned where accidental collision may be likely, should be made apparent by some form of manifestation (marking). Differences in the design of manifestation used can also assist in identifying the position of doors within a glazed screen.

Manifestation should be of a size and form that is immediately obvious. It should, as far as is reasonably practicable, contrast visually with backgrounds viewed through the glazing by a person approaching from either side. Forms might include broken or solid lines, patterns or logos and may be a continuous element or at appropriate horizontal intervals. Manifestation should be present within 2 height ranges, between 850mm and 1.0m, and between 1.4m and 1.6m above floor level. It should be permanent, e.g. screen printed or opaque etching or a durable applied material which is not easily removed.

In addition, any unframed glazed door which operates on a pivot action should have any exposed vertical edge highlighted to contrast visually with surroundings, to assist in identifying the door edge when opening or in an open position. This is particularly important on powered doors.

4.8.3 Cleaning of windows and rooflights

Falls account for most window cleaning accidents, and generally occur from loss of balance through over-extension of reach or due to breakage of part of the building fabric through improper use or access. It is therefore important that all transparent or translucent glazing should be designed so that it may be cleaned safely.

There is, however no need to provide for the safe cleaning of any glazed element that is opaque and does not allow the passage of light.

Any window or rooflight, all or part of which is more than 4m above the adjacent ground or internal floor level, should be constructed so that any external and internal glazed surfaces can be cleaned safely from:

  1. inside the building in accordance with the recommendations of Clause 8 of BS 8213: Part 1: 2004, or

  2. a loadbearing surface, such as a balcony or catwalk, large enough to prevent a person falling further, or

  3. a window access system, such as a cradle or travelling ladder, mounted on the building, as described in Annex C3 of BS 8213: Part 1: 2004, or

  4. a ladder sited on adjacent ground or from an adjacent loadbearing surface which has unobstructed space large enough to allow the safe use of a ladder and which will contain a person from falling further. However a ladder should not be used to access any external or internal glazed surface more than 9m above the surface on which the ladder is sited. General guidance on the safe use of ladders may be found in HSE information sheet MISC613 'Safety in window cleaning using portable ladders'.

Glazing within a roof access hatch, located within a roof space, need not be constructed so that it may be safely cleaned.

When cleaning a window from inside, a person should not have to sit or stand on a window sill or use other aids to reach the external face of a window. The criterion of safety is the ability to reach all points on the surface of the external glazing with only the arm projecting outside the line of the window whilst remaining standing on the floor.

Safe reach - ergonomic statistics on reach capabilities for the UK adult population are given in Annex A of BS 8213: Part 1: 2004. As reach may safely be increased to some degree by use of cleaning implements, it would still be considered reasonable to apply a safe limit to downward reach of 610mm and a safe limit to lateral and vertical reach as an arc with a radius of 850mm measured from a point not more than 1.3m above floor level.

Cleaning from a loadbearing surface - where the window is to be cleaned from a loadbearing surface noted in subclause (b) to this clause, there should be provided:

  • a means of safe access, and

  • a protective barrier not less than 1.1m high to any edge of the surface or access which is likely to be dangerous.

This method of cleaning is only appropriate where no part of the glazing is more than 4m above the loadbearing surface.

Alternative methods - where there is a need for safe cleaning of glazing, it may be appropriate to consider alternate methods of cleaning, in addition to those listed in the guidance, where an equivalent level of safety can be demonstrated.

4.8.4 Guarding of windows for cleaning

For openable windows on the ground and first floor of a building, or where the outside face of the glazing will not be cleaned from inside the building, no guarding need be provided for the purpose of cleaning glazing. However the general guidance for provision of protective barriers given in clause 4.4.2 should be followed.

At greater heights, 2 storeys or more above ground level, where it is intended to clean the outside face of the glazing from inside the building, the increased risk from a fall should be recognised and guarding provided to a height of at least 1.1m above floor level.

Where guarding is provided, it should be designed to conform to BS 6180: 2011. All guarding should be permanently fixed and should not be detachable to permit windows to open. Guarding should be designed so that it is not easily climbable by young children unless their presence of within the building is precluded.

Guarding to a window is not needed where the open window gives access to a fully guarded balcony.

4.8.5 Emergency stopping of escalators and passenger conveyors

Escalators and passenger conveyors should be provided with devices capable of being readily operated that, when activated, can bring the equipment to a controlled halt in such a way that passengers will be able to maintain their balance.

The location of the devices and the stopping of the equipment should meet the recommendations of BS EN 115: 1995.

4.8.6 Access to manual controls

The location of a manual control device can have a significant effect on both the ease of operation of the device and safety in use. Positions that are inaccessible present a greater risk of accident when bending or reaching. Any control that is intended for operation by the occupants of a building should be installed in position that allows safe and convenient use.

This guidance is applicable to manual controls to openable ventilators, including windows and rooflights and to controls and outlets of electrical fixtures located on a wall or other vertical surface. Unless incorporating a restrictor or other protective device for safety reasons, controls should be operable with one hand.

An openable window, rooflight or other ventilator, intended to be operable by building occupants to provide natural ventilation, should have controls for opening, positioned at least 350mm from any internal corner, projecting wall or similar obstruction and at a height of:

  • not more than 1.7m above floor level, where access to controls is unobstructed, and

  • not more than 1.5m above floor level, where access to controls is limited by a fixed obstruction, not more than 900mm high which projects not more than 600mm in front of the position of the controls. Where obstruction is greater, a remote means of opening, in an unobstructed location, should be provided, and

  • not more than 1.0m above floor level, in an unobstructed location, in any room intended specifically for use by a wheelchair user, such as an accessible bedroom.

The above guidance does not apply to windows or rooflights openable only for cleaning or maintenance purposes or that are controlled by an automatic system, or to trickle ventilators.

Outlets and controls of electrical fixtures and systems should be positioned at least 350mm from any internal corner, projecting wall or similar obstruction and, unless the need for a higher location can be demonstrated, not more than 1.2m above floor level. This would include fixtures such as sockets, switches, fire alarm call points and timer controls or programmers. Within this height range:

  • light switches should be positioned at a height of between 900mm and 1.1m above floor level

  • standard switched or unswitched socket outlets and outlets for other services such as telephone or television should be positioned at least 400mm above floor level. Above an obstruction, such as a worktop, fixtures should be at least 150mm above the projecting surface

  • in accommodation specifically intended for wheelchair users, such as accessible bedrooms, operable controls should be located at a height of not more than 1.0m above floor level.

Where sockets are concealed, such as to the rear of built-in appliances, or obstructed by built-in furniture, separate switching should be provided in an accessible position, to allow appliances to be isolated.

4.8.7 Roof access

Working on roofs can be dangerous. Falls account for more deaths and serious injuries in the construction industry that any other cause. Any fall from a roof inevitably involves, at least, serious injury - the risks are substantial.

A means of safe and secure access should be provided to a roof of a building. One method of providing such access would be the installation of a stair, ladder or walkway meeting BS 5395: Part 3: 1985.

Access as described above need not be provided to a roof having eaves that, at any part, are at a height of less than 4.5m above the adjacent ground.

Alternative access - where access may occur on a very infrequent basis, it may not be appropriate to provide permanent access. In such cases, alternative access options might include a mobile platform or zip-up scaffolding in accordance with the guidance in HSE publications.

Unauthorised access - where fixed ladders are provided and could be accessible to the public, it would be appropriate to make the lowest section of the ladder (up to 4.5m) demountable to prevent unauthorised access.

4.8.8 Working on roofs

Where access to roofs is provided, precautions should be taken to limit the hazards presented by fragile roof surfaces.

There should be a clear visible warning identifying any part of a roof that is not capable of bearing a concentrated load of 0.9 kN on a 130mm by 130mm square. The visible warning should include the relevant hazard sign from BS 5499: Part 5: 2002.

Back to top