Last edited 04 Dec 2015

Door clear opening width

Approved document M, ‘Access to and use of buildings', requires that a minimum clear width is provided by door openings.

According to the approved document, the effective clear width of a door ‘…is the width of the opening measured at right angles to the wall in which the door is situated from the outside of the door stop on the door closing side to any obstruction on the hinge side, whether this be projecting door opening furniture, a weather board, the door or the door stop’

Effective clear width of doors.jpg

The minimum allowable clear opening widths for dwellings are set out below:

Doorway clear opening width (mm) Corridor clear passageway width (mm)
750 or wider 900 (when approached head on)
750 1200 (when approach is not head-on)
775 1050 (when approach is not head-on)
800 900 (when approach is not head on)

For buildings other than dwellings, the minimum allowable clear opening widths are:

Direction and width of approach New buildings (mm) Existing buildings (mm)
Straight-on 800 750
At right angles to an access route at least 1,500 mm wide 800 750
At right angles to an access route at least 1,200 mm wide 825 775
External doors to buildings used by the general public. 1000 775

The clear opening width can be calculated as:

  • The width of the door leaf.
  • Plus the gap between the leading edge of the door and the frame when the door is closed.
  • Minus the width of the door stop at the leading edge of the door.
  • Minus the thickness of the door leaf (or the door stop if that is wider).
  • Minus the width of any obstructing door furniture (such as the door handle) that projects into the opening when the door is open. If the door opens to more than 90°, door furniture may not obstruct the clear opening width.

Door clear opening width.jpg

Unless a door is powered, there must be a 300mm nib beyond the leading edge of the door to allow wheelchair users to properly access the handle.

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