10 November 2022
The accessible washroom dimensions for an enlarged unisex toilet cubicle must be equal to or greater than 2000mm(w) x 2200mm(l).
Where only one enlarged unisex toilet is provided within a building, Document M indicates a large washbasin be included in addition to the hand rinse basin next to the WC to accommodate people with ambulant mobility impairments. The large washbasin’s rim should measure 780mm and 800mm above the finished floor level.
In this plan view, the wheelchair turning space encroaches on the mounted fittings (disposal bin, shelf, hand rinse basin, grab rails, and WC). Each fitting has dimensions associated with the installation of height above the floor and projection to allow clear space for the wheelchair user to turn underneath them.
If only one accessible washroom can be provided in an environment, BS8300 stipulates it should be a unisex type and preferably designed for a right-hand transfer technique.
The accessible washroom dimensions for a standard unisex toilet cubicle where other accessible toilet accommodation is available must be equal to or greater than 1700mm(w) x 2200mm(l).
Where more than one unisex accessible washroom can be accommodated in a building, a choice of layouts suitable for right and left-hand wheelchair transfer techniques should be provided. The drawing to the left is a right-hand transfer accessible WC.
The wheelchair turning space can be free from infringing on any of the Doc M fittings and gives a wheelchair user ample room to move around in the washroom as there is extra clear space underneath the wall mounted fittings outside of the turning zone.
UK Doc M dimensions
What is interesting about the accessible washroom dimensions mentioned in Document Part M of the Building Regulations is it specifies the Doc M measurements as a minimum of 1500mm width for a corner layout. This measurement conflicts with the recommendations provided by BS8300.
This could very well be the ultimate minimum size for an accessible washroom but in terms of good practice based on user trials from BS8300 Standards, this may not be the most comfortable accessible design layout for a wheelchair user.
Considering the wheelchair turning space is the same width as the minimum room dimension, the washroom may feel somewhat cramped regardless of the clear space underneath the fittings. At the end of the day, designing a washroom is all about the user experience and not compromising quality.
Accessible WC pan dimensions
Whether the Doc M toilet pan is wall hung, floor mounted, or close coupled, the dimensions of the accessible WC pan must project 750mm from the back wall and measure 480mm from the floor to the toilet seat.
Hand rinse basin
Hand rinse basins next to the WC pan in a unisex accessible toilet should not project further than 250mm and can be at a lower level for easy reach and use from the WC. The rinse basin rim height should be between 720mm to 740mm above the floor to allow standing users to wash their hands as well as seated users.
Doc M mirror
Tall mirrors located away from the hand rinse basin should be set at maximum 600mm above the finished floor level (FFL) to the bottom of the mirror, and the mirror should be at least 1000mm tall.
Doc M guidance and BS8300 recommendations for WC compartments
BS8300-2:2018 Section 18 focuses on WC compartments and the accessible washroom dimensions in buildings to meet the needs of disabled people. It is a code of practice where the recommendations are based on user trials and validated desk studies, whereas Doc M gives practical guidance and minimum requirements that accompanies Building Regulations.
Although Doc M notes that more detailed recommendations regarding sanitary and other fittings are in BS8300, these two documents essentially work together for the ultimate best practice to ensure a safe, accessible washroom for wheelchair users. The guidance in the Approved Document M is complementary to BS8300, but BS8300 is not necessarily equivalent to compliance with Doc M and vice versa.
It is safer to refer to both BS8300 and Document part M when working out accessible washroom dimensions to ensure you are covered by both Standards to meet the Building Regulations in room size, layout, and placement of fixtures and fittings.
Ultimately, the answer to the question about accessible washroom dimensions depends on the type of accessible washroom you are designing. One size does not fit all because there are different variations of commercial accessible washrooms with recommended measurements and layouts. As long as you are meeting the minimum requirements, there should be no concerns about the compliance factor of your accessible washroom design.
Explore the Dolphin Doc M pack range to better understand what a Doc M pack includes and which type you will need for your accessible washroom.
