Enhancing the accessibility, adaptability and usability of Scotland's homes: consultation

Annex B – Section 2 of Part 1 of the current Housing for Varying Needs design guide: Sizes and dimensions

The clauses within Section 2 of Part 1 of the current Housing for Varying Needs design guide are set out in the table below.

2 Sizes and dimensions

2.1 Assumptions

The design of buildings in general makes certain assumptions about the size and abilities of the people who use them – the height and width of door openings, the size of steps etc, and these are integral with the requirements of the Building Standards Regulations and other standards. But people vary in height and in their ability to bend or reach. When the needs of all people are taken into account some assumptions have to be reconsidered.

2.2 Anthropometrics

This design guidance assumes a reach within the following distances (mm) from floor level: - general use upward 1800 - general use upward grip 1700 - general use downward 400 - older and ambulant disabled people upward 1600 - older and ambulant disabled people upward grip 1500 - older and ambulant disabled people downward 500 - wheelchair user upward 1350 - wheelchair user upward grip 1200, and - wheelchair user downward 600.

2.3 Walking aids

Walking aids may take the form of sticks, crutches or frames. Typical dimensions are a width of 550mm – 600mm for a walking frame and a spread of up to 800mm for elbow crutches or walking sticks.

2.4 Wheelchair sizes

As there is no standard size for people, there is no standard wheelchair size. People with different forms of disability need wheelchairs of different forms and many users will have more than one chair. The design criteria presume dimensions of 1100mm by 700mm for a chair that is used indoors.

2.5 Wheelchair manoeuvres

2.5.1 The space needed by someone in a wheelchair, particularly to turn round, will vary. Obviously it will depend on the size and workings of the wheelchair, but also on the ability of the user. Where wheelchair turning is needed it is more likely to be through 180^o rather than a full circle and the profile of this movement is usually elliptical rather than circular, with dimensions of 1400mm by 1700mm. In certain configurations of space, especially between pieces of furniture users may use three point turns. But some flexibility in the choice of turning methods is desirable and therefore as a practical guideline the criteria for sufficient space to turn a wheelchair is taken as a clear circular space of 1500mm diameter. This will never be a completely confined area and the adjoining space will usually give some flexibility in use.

2.5.2 In refurbishment or adaptation situations it may be only be possible to allow for one turning method.

Fig 2.1 wheelchair turning

2.5.3 Another crucial action for a wheelchair user is that of opening a door, particularly reaching the handle. This involves a person bending or leaning forward in their wheelchair and people's ability to do this will vary. A clear space of 300mm is generally accepted as the required dimension and this suffices for the majority. However, people who are unable to lean forward will require to bring the side of their chair alongside the handle. To allow for this there needs to be a clear space of at least 550mm beyond the opening edge of the door.

Fig 2.2 opening a door

2.5.4 Formulas for the relationship of necessary dimensions for wheelchair manoeuvre are given in European Concept for Accessibility [4]. This advocates that the space to the side of the door plus the clear space in front of the door swing should equal or be greater than 1400mm. Also that to turn into a door at right angles to a passage the clear width of the door plus the width of the passage should equal or be greater than 2000mm.

Fig 2.3 wheelchair manoeuvre

2.5.5 Externally any surface on which a wheelchair may need to be stationary must be nominally level.

2.6 Door widths

2.6.1 In this guidance different widths are cited for doors that will allow wheelchair users to pass through. In any situation there is always the minimum width of what is physically possible and a more convenient width. Most able bodied people can pass through a space with a clear opening width of 600mm, or even less, but for convenience doors are usually wider than this. Similarly a person in a wheelchair can pass through a space 750mm wide, but this manoeuvre has to be done with care as the tolerances are very small. In a wheelchair user's own home easier movement than this should be possible and a clear width of at least 800mm should be provided. The clear width of external doors must make allowance for a weather moulding at the foot of the door and the required widths of external doors are therefore greater by 50mm to allow for this.

2.6.2 Also in suggesting suitable dimensions for doors recognition has to be given to the ‘standard’ door sizes that are readily available, though this is not to say that manufacturers should not be encouraged, through demand, to add components to their standard ranges. While an ‘adequate’ width may be acceptable where this allows a standard component to be used, if a purpose made component is needed the most satisfactory width should be achieved.

2.6.3 The criteria given in this guidance to apply generally are the minimum to allow possible wheelchair use, but for regular use by someone in a wheelchair the more convenient size is given.