Clear opening width of an internal door

750 mm from a corridor at least 900 mm wide; 775 mm from a 825 mm corridor; 900 mm from a 750 mm corridor

Internal doorway on the entrance storey of a dwelling

Clear opening width required of an internal door, which varies with the width of the corridor approaching it.

Basis in regulation

Part M
Approved Document M
Read the source

How to check it on site

Measure the clear opening with the door at 90°, from the face of the door to the opposite stop — not the structural opening.

Common failure

Door leaf sized to the structural opening, so ironmongery and stops take the clear width below the limit.

Last updated 23 August 2026. This is our editorial summary of publicly available regulation, not building control approval or a warranty determination.

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Stair Handrail Height and Clearance

600 mm

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