Accessible WC Calculator - Doc M Wheelchair Toilet Dimensions

A unisex wheelchair-accessible WC per Approved Document M Volume 2 (Diagram 18) requires a minimum room size of 1500mm wide x 2200mm long. This allows space for a 1500mm x 1500mm wheelchair turning area, the WC pan, wash basin, and lateral transfer from wheelchair to WC. Where it is the only toilet in the building the width increases to 2000mm (para 5.10(e)). The door is governed by Table 2 of Approved Document M: its minimum effective clear width is 800mm in new buildings (750mm in existing buildings) for a door at right angles to an access route at least 1500mm wide. There is no separate 950mm door rule in Doc M.

A Doc M pack is a set of sanitaryware and fittings designed to meet Approved Document M requirements for accessible WCs. A standard pack includes: close-coupled WC pan with raised flush, wash basin, drop-down support rail, fixed support rails, back rest, mirror, shelves, coat hook, toilet roll holder, and alarm pull cord. Fittings are typically in contrasting colour (blue/white) for visually impaired users.

Doors to wheelchair-accessible WCs must open outwards or be sliding doors to ensure a wheelchair user is not trapped if they fall from their wheelchair inside the cubicle. An inward-opening door could block against a person on the floor, preventing rescue. The door must also be openable from outside in an emergency.

Ambulant disabled WCs are for people with mobility impairments who can walk (possibly with sticks or crutches) but do not use a wheelchair. Approved Document M Diagram 21 sets a minimum cubicle of 920mm wide x 1465mm deep with grab rails on the side wall and a vertical rail at the entrance. Wheelchair-accessible unisex WCs are larger (1500mm x 2200mm, Diagram 18) with a 1500mm turning area and lateral transfer space. Non-domestic buildings commonly need both types: a unisex wheelchair-accessible WC plus ambulant cubicles within the separate-sex washrooms.

Approved Document M Volume 2 expects at least one wheelchair-accessible unisex WC per floor in buildings other than dwellings, in addition to ambulant disabled cubicles within the standard WC blocks. Para 5.10(h) of Approved Document M states that a wheelchair user should not have to travel more than 40m on the same floor to reach a wheelchair-accessible unisex toilet (or more than 40m combined horizontal distance where it is reached on another floor by lift). The exact number depends on building use, occupancy and total WC provision.