Part M Door Width Requirements

For a new dwelling meeting M4(1) (Visitable dwellings), the minimum effective clear width of the principal entrance door is 775 mm (per AD M Vol 1 2015 Section 2 Table 2). Internal doors should also provide a minimum clear opening width of 775 mm (typically achieved with an 826 mm / 2'9" door leaf). Effective clear width is measured between the door stop on the latch side and the face of the open door. The 850 mm figure often quoted online applies to M4(2) and M4(3), not the default M4(1) standard.

For M4(2) (Accessible and adaptable dwellings), the principal entrance door requires a minimum 850 mm effective clear width (AD M Vol 1 2015 Table 3). Internal doorways must have a minimum 775 mm clear width with straight-on approach, or 900 mm where there is a side approach. For M4(3) (Wheelchair user dwellings), the principal entrance and all doorways typically need 850 mm clear width for straight approach and 1,000 mm for side approach (Table 4).

M4(1) Visitable dwellings is the default standard for all new homes — it requires level or ramped access, WC at entry level, and reasonable door widths. M4(2) Accessible and adaptable dwellings has enhanced requirements (wider doors, step-free access, adaptable bathroom, space for future wheelchair turning). M4(3) Wheelchair user dwellings are fully designed for wheelchair use. M4(2) and M4(3) are only required if specified by a planning condition.

AD-M recommends that doors to common corridors in flats should have vision panels to allow people on both sides to see each other. Vision panels should have a zone of visibility between 500 mm and 1,500 mm above floor level. For M4(2) and M4(3) dwellings, glazed panels in doors should also include manifestation at two heights for partially sighted people.