Building standards technical handbook 2019: domestic

The building standards technical handbooks provide guidance on achieving the standards set in the Building (Scotland) Regulations 2004. This handbook applies to a building warrant submitted on or after 1 October 2019 and to building work which does not require a warrant commenced from that date.

4.1 Access to buildings

Mandatory Standard

Standard 4.1

Every building must be designed and constructed in such a way that all occupants and visitors are provided with safe, convenient and unassisted means of access to the building.


There is no requirement to provide access for a wheelchair user to:

  1. a house, between either the point of access to or from any car parking within the curtilage of a building and an entrance to the house where it is not reasonably practicable to do so, or

  2. a common entrance of a domestic buildings not served by a lift, where there are no dwellings entered from a common area on the entrance storey.

4.1.0 Introduction

An inclusive approach to design should be taken to ensure that buildings are as accessible to as wide a range of people as possible. Solutions should be integral to a design rather than an afterthought added in order to meet duties under building standards or other legislation.

Inclusive design is not just relevant to buildings. It applies throughout any internal or external environment, wherever people go about everyday activities. It should be a continuous process, through all stages of the development of a building and involve potential users. Advice on this topic is available in the joint BSD/Scottish Executive Planning Division Planning Advice Note PAN 78: ‘Inclusive Design’ which promotes the merits of an inclusive approach to the design of the built environment.

Whilst the guidance to this standard reflects general good practice, certain issues remain outwith the scope of the building regulations. There are numerous publications offering additional guidance on accessibility and inclusive design, including those listed below:

  • BS 8300: 2009 – ‘Design of buildings and their approaches to meet the needs of disabled people – code of practice’

  • Housing for Varying Needs, Parts 1 & 2 - Communities Scotland

  • 'Inclusive Mobility' – Department of Transport, 2002

  • ‘Guidance on the Use of Tactile Paving Surfaces’, published jointly by The Scottish Office and the Department for the Environment, Transport and the Regions (DETR).

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 conversions (regulation 12, schedule 6).

4.1.1 Accessible car parking to flats or maisonettes

The need for car parking serving a domestic buildings will commonly be determined by a developer and may also be a condition of planning permission. Where car parking is provided within the curtilage of a building containing flats or maisonettes, it should include accessible spaces.

A proportion of car parking spaces should be designed to be accessible to a person with mobility impairment, including a wheelchair user, and designated for use as such. These parking spaces should be:

  1. provided on a ratio of at least 1 per 20 parking spaces, or part thereof, and

  2. located on a road surface that is level (with a gradient of not more than 1 in 50), and

  3. not more than 45m from a common entrance, and

  4. clearly marked with the international symbol of access, and

  5. provided with a dropped kerb access to an accessible route, and

  6. where perpendicular or at an angle to a road, at least 4.8m long x 2.4m wide, outwith which a delineated access zone at least 1.2m wide to each long side and between the end of the bay and any road is shown, or

  7. where parallel to a road, at least 6.6m long by 3.6m wide, as shown below.

Figure 4.1. Off- and on-street accessible car parking

Off- and on-street accessible car parking

4.1.2 Car parking within the curtilage of a dwelling

Where car parking is provided within the curtilage of a dwelling, a person should be able to alight from a vehicle directly onto the firm surface of an accessible route to the dwelling.

Where a driveway or car parking space forms part of an accessible route to a dwelling, it should be at least 3.3m wide to allow a 900mm wide pedestrian route past a parked car. That portion of the driveway surface should be in accordance with the recommendations in clause 4.1.4.

4.1.3 Accessible routes

Regardless of how they arrive within the curtilage of a building, a person should then be able to travel conveniently and without assistance to an entrance of a building. Routes to a building that are too steep, too narrow or poorly surfaced, or that contain steps or other obstructions, will make access difficult or impossible for many people. To prevent this, a route to an entrance should be provided that is accessible to everyone.

An accessible route should contain no barriers, such as kerbs, steps or similar obstructions that may restrict access. Street furniture can present a hazard, particularly to a wheelchair user or a person with a visual impairment and should be located outwith the width of an accessible route. Use of low-level bollards or chain-linked posts, for example, can be particularly hazardous.

There should be an accessible route to the accessible entrance of a single dwelling from:

There should be an accessible route to the common entrance of a building containing flats or maisonettes and to an accessible entrance of any dwelling not reached through a common entrance, from:

  • a road, and

  • any accessible car parking (see clause 4.1.1) within the curtilage of the building.

Gradient of accessible route - as steeper gradients are more difficult to negotiate, level or gently sloping routes should be used where possible, in preference to ramps. An accessible route should be:

  • level, which for the purpose of this guidance is a gradient of not more than 1 in 50, or

  • gently sloping, which for the purpose of this guidance is a gradient of more than 1 in 50 and not more than 1 in 20, or

  • ramped, with a gradient of more than 1 in 20 and not more than 1 in 12

The cross-fall on any part of an accessible route should not exceed 1 in 40.

Gently sloping gradients should be provided with level rest points of not less than 1.5m in length, at intervals dependent on the gradient of the sloping surface. This should follow the same relationship given for ramp flights, e.g. up to 20m apart for a slope of 1 in 30, 30m for a slope of 1 in 40 and so on.

Recommendations for ramps are provided in the guidance to Standard 4.3.

Complementary steps - ramps are not necessarily safe or convenient for an ambulant person with mobility impairment, and can be more difficult and dangerous to negotiate than steps. Therefore, on a route serving more than 1 dwelling, any ramped access, having a rise of more than 300mm, should be complemented by an alternate, stepped means of access.

There may be stepped access to a route serving a single house where it is not reasonably practicable to construct an accessible route, such as on a steeply sloping site. As a guideline, if a ramp to an accessible entrance can be formed within the curtilage of the dwelling with one change in direction between the bottom of the ramp and the top landing, access should be considered reasonably practicable.

Where an accessible route cannot be provided from a road, it may still be practicable to construct an accessible route by providing a car parking space within the curtilage of the dwelling. It is only where it is not reasonably practicable to construct an accessible route from either a road or from car parking within the curtilage of the dwelling that a stepped access solution may be proposed.

4.1.4 Surface to accessible routes

For safety and convenience in use, the surface of an accessible route should be firm, uniform and of a material and finish that will permit ease in manoeuvring. It should provide a degree of traction that will minimise the possibility of slipping. This should take into account both anticipated use and environmental conditions.

The surface of an accessible route, whether composed of modular paving units, formless materials such as tarmac, or another durable material, should have a profile that will not offer a trip hazard or result in standing water. It should be installed in accordance with a code of practice relevant to the material, where such exists.

Surface elements such as drainage gratings and manhole covers should be of a type that will not create a trip or entrapment hazard. Uneven surfaces, such as cobbles, or loose-laid materials, such as gravel, will present difficulties to many people and should not be used.

Tactile paving - at a location where the footpath is level with a road surface, such as at a dropped kerb, tactile paving should be used to provide warning to a person with a visual impairment of the presence of a vehicular route. This need not apply to a route within the curtilage of a single dwelling. Information on use of tactile paving on footpaths is given in 'Guidance on the Use of Tactile Paving Surfaces'.

4.1.5 Length of accessible routes

The longer a pedestrian route, the greater difficulty it can present to many people. Therefore, in addition to minimising gradients where possible, as recommended in clause 4.1.3, the length of an accessible route to an accessible entrance of a building should be limited to 45m.

4.1.6 Width of accessible routes

The width of a pedestrian route to a building should reflect how it will be used. For example, most public footpaths are at least 1.8m wide, which allows two-way traffic under most circumstances.

The clear and unobstructed surface width of an accessible route should generally be at least 1.8m, unless:

  • giving access to not more than 10 dwellings, where the minimum surface width may be not less than 1.2m. This will accommodate any person where traffic is in a single direction of travel. To allow for passing, localised widening of any route less than 1.8m wide to at least 1.8m should be made at any junction and change of direction and, where the whole length of the route is not visible, also at not more than 10m intervals along the route, or

  • giving access to a single dwelling, where effective width may be not less than 900mm, recognising reduced levels of traffic.

On an accessible route serving more than one dwelling, a level footpath of not less than 1.0m in width should be maintained to the rear of the slope of any dropped kerb.

Any gate across an accessible route should offer a clear opening width of at least 850mm.

4.1.7 Accessible entrances

Each common entrance to a domestic buildings and at least one entrance to a dwelling should be an accessible, designed to present as little restriction to passage as possible.

Whilst an accessible entrance to a house is commonly the front or main entrance, an alternate entrance may be designated as the accessible entrance where this provides a more convenient or practical route into the dwelling.

An accessible entrance to a building should:

  1. have an unobstructed entrance platt of at least 1.2m by 1.2m, with a crossfall of not more than 1 in 50, if required to prevent standing water, and

  2. have a means of automatic illumination above or adjacent to the door, and

  3. have an accessible threshold, and

  4. have a door leaf giving a clear opening width of at least 800mm in accordance with the diagram below, and

  5. if fitted with a door closing device, be operable with an opening force of not more than 30N (for first 30º of opening) and 22.5N (for remainder of swing) when measured at the leading edge of any door leaf, and

  6. if not a powered door, have an unobstructed space to the opening face of the door, next to the leading edge, of at least 300mm.

However where there is not an accessible route to a single house, the guidance in sub clauses (a) and (c) above need not be followed.

Figure 4.2. Accessible entrance door

Accessible entrance door

Clear opening width - the projection of ironmongery which extends across the width of a door leaf, such as an emergency push bar for escape or a horizontal grab rail, should be subtracted when calculating the clear opening width.

4.1.8 Common entrances

In addition to the recommendations in clause 4.1.7, a common entrance to a domestic buildings should have:

  1. an unobstructed entrance platt, measuring at least 1.5m by 1.5m, with a crossfall of not more than 1 in 50 if required to prevent standing water, and

  2. a canopy, recessed entrance or similar means of protecting people entering the building from exposure to the elements, and

  3. a glazed vision panel, as described below, and

  4. a door entry system.

Weather protection - the form that weather protection should take will vary with location and exposure of the building. However an example of minimum provision might be a canopy or recess, 750mm deep, across the width of the entrance platt, with an underside not more than 2.3m above entrance level. It is recognised that there are circumstances where provision of weather protection may not be practicable or may be constrained by other permissions.

Glazed vision panels - to assist in preventing collisions, a clear glazed vision panel or panels to a door should give a zone of visibility from a height of not more than 500mm to at least 1.5m above finished floor level. This may be interrupted by a solid element between 800mm and 1.15m above floor level. A vision panel is not needed to a powered door controlled by automatic sensors or where adjacent glazing offers an equivalent clear view to the other side of a door.

Guidance relevant to specific door types such as revolving doors or powered doors is given in the non-domestic Technical Handbook.

4.1.9 Accessible thresholds

To be accessible, a door should not present unnecessary barriers to use, such as a step or raised profile at a threshold that might present difficulties to a wheelchair user or be an entrapment or trip hazard to an ambulant person, whether or not using a walking aid.

Figure 4.3. Generic threshold profile

Generic threshold profile

An accessible threshold should meet the following criteria:

  • thresholds should be designed to prevent the ingress of rain. Details in the DETR publication ‘Accessible Thresholds in New Housing’ gives guidance on how this might be achieved

  • externally, the surface of the platt should be not more than 10mm below the leading edge of any sill, with any exposed edge chamfered or rounded

  • an external sill or internal transition unit should be at an angle of not more than 15º from the horizontal and, if sloping, be not more than 150mm in length

  • the threshold should either be level or of a height and form that will neither impede unassisted access by a wheelchair user nor create a trip hazard. A threshold piece should have a height of not more than 15mm, with any vertical element of more than 5mm height being pencil-rounded or chamfered to an angle of not more than 45º from the horizontal

  • if the finished internal floor level is more than 15mm below the top of the threshold, an internal transition unit, of not more than 15º to the horizontal, finishing not more than 5mm above the internal floor surface may be used, in accordance with the guidance above. In new buildings, this should normally only be needed to allow flexibility in subsequent fitting of differing thickness of floor coverings.

4.1.10 Alteration and extension

Where a dwelling is altered or extended, this work should not adversely affect an existing accessible entrance.

Where a dwelling does not have an accessible entrance, one need not be provided to the existing dwelling, or to the extension, as this will not result in the building failing to meet the standard to a greater degree.

Where an accessible entrance exists, any works should ensure that the existing entrance remains accessible. If this is not possible, a new accessible entrance should be provided elsewhere into the dwelling. Such an entrance should also maintain accessibility within the dwelling, as set out in guidance to Standard 4.2.

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