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’
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.
Unless a door is powered, there must be a 300 mm nib beyond the leading edge of the door to allow wheelchair users to properly access the handle.
[edit] Find out more
[edit] Related articles on Designing Buildings Wiki
Featured articles
Check out some of the best features and news from Designing Buildings as well as key stories from around the web.
New Prime Minister delivers on ECA call for cut in electricity costs.
CIOB reacts to the announcement of Andy Burnham as Prime Minister.
Heritage and conservation science workforce survey - Have your say.
England's Suburbs 1820-2020. Book review.
New, more proportionate and targeted approach for higher-risk building assessments.
Government brings British Steel into public ownership.
UKCW Birmingham returns with bold new theme and focus.
New guidance published on competence requirements for self-certification schemes.
Construction Management, 8 July
NEETs crisis drives interest in trades, but apprenticeships barriers remain.
Passive fire protection webinar
MEP services penetration seals.
Where its at podcast (and video) - The role of the Architectural Technologist as an Expert Witness.
More than 200 remarkable buildings added to SAVE’s Buildings at Risk register.



















