How to design an accessible toilet with a BIM software

What you need to know about designing an accessible toilet: Guidelines with dimensions, regulations, features, materials and a 3D BIM model ready for download

Need to design an accessible toilet which is compliant with your local standards? This article provides all the tools and sizing criteria to design more inclusive architecture. Although each country has its own accessibility guidelines, we’ll be referring specifically to building regulations available for the US and UK, as well as to guidelines for the ASEAN Member States in a section at the bottom of the article. There’s also a 3D model with DWG CAD resources (complete with floor plans, cross-sections, 3D views, renderings, etc.) ready for you to use for your projects.

To open the file, start off by downloading Edificius – the 3D Building Design Software, the BIM architectural design software used to create the project, renders and the project drawings available below.

Accessible toilet – Interior render produced with Edificius

Important features to consider when designing an accessible toilet for users with disabilities

When designing an accessible toilet, it’s important to consider a set of parameters that are essential for its proper functioning and accessibility, being some of the conditions recently required in many countries to achieve equal opportunities and social inclusion of people with disabilities.
Crucial features of inclusive spaces design allow wheelchair users and individuals with a range of (physical) disabilities to use the toilet as independently and safely as possible.
In fact, the purpose of an accessible toilet should be to enable persons with reduced mobility to easily access facilities that are different from regular toilets in terms of layout, available space, equipment, flooring, lighting etc., hence removing disabling barriers and restrictions that might be present.

Accessible toilets regulations and standards

British accessibility standards

The most relevant guidance for providing accessible toilets is to be found in:

• British Standard 8300 (2009) – Design of buildings and their approaches to meet the needs of disabled people.
• Approved Document M: Access to and use of buildings – Volume 2: Buildings other than dwellings (Section 5: Sanitary accommodation).

USA ADA construction guidelines for Accessible toilets

The American with Disabilities Act (ADA) of 1990 includes specific accessibility guidelines and design requirements for building accessible, or ADA-compliant, public or commercial toilets. They can also serve as a general guide for safe, user-friendly, accessible design when ADA compliance is not required.

As always, please check your local building regulations prior to commencing any construction work. Remember that local code authorities may impose additional or modified requirements.

The essential features of an accessible toilet

Generally, the most important elements to consider when designing comfortable and efficient spaces for all toilet users are:

1. a raised height Water Closet
2. handrails
3. outward swinging door with an emergency release mechanism
4. toilet door signs for the disabled
5. drop down hinged rail
6. a wash basin with boxed in pipes and with lever-handle taps or with activation sensors
7. a mirror to enable people to see themselves in the standing or seated position.

Essential elements to consider when designing an accessible toilet – Layout produced with Edificius

Disabled toilet dimensions and manoeuvring space

One of the most important points of designing an accessible toilet is to verify that physical access to the compartment is good. The manoeuvring space should enable wheelchair users to adopt various transfer techniques that allow independent or assisted use.

Standard cubicle dimensions – UK

Compulsory dimensions for a disabled toilet state that the room needs to be at least 220cm in length and 150cm in width.
These are of course just the minimum requirements. Dimensions larger than these will give a wheelchair user a larger turning circle, providing greater comfort. Document M contains a diagram of a compliant disabled toilet, which should help you understand if you’re meeting all the necessary requirements.

Sufficient manoeuvring space outside the door to the WC – 150cm x 150cm should be, however, regarded as the minimum.

A standard WC layout meets the needs of some people but not all with a minimum 45cm space between the edge of the WC and the door swing. An enlarged WC aids some people in maneuvering due to the additional space provided by the 75cm space between the edge of the WC and the door which opens outwardly.

Accessible stall dimensions – USA

According to ADA Guidelines for Accessible toilets, standard toilet stalls with a minimum depth of 56 in (142 cm)  shall have wall-mounted water closets. If the depth of a standard toilet stall is increased at least 3 in (75 mm), then a floor-mounted water closet may be used.

Standard stall dimensions for a single-user should be 59 in (150 cm) by 95 in (214 cm).

Rotating Space

Some people need carer support, space, a hoist to transfer from wheelchair to toilet or a bed to lay on to remove clothing, use a catheter, have a continence pad changed. The minimum space required, from the edge of the seat to the nearest frontal obstacle, should be at least of 65-75 cm (UK)

A single wheelchair must be able to rotate freely inside a bathroom. For this kind of motion, a clear floor space of at least 60 inches in diameter is required, allowing a 180-degree turn (USA).

Accessible toilet with standard dimensions: floor plan created with Edificius

For the accessible toilet project that we have created, we have used standard dimensions that you can edit according to your national or local requirements. You can create conforming floor plans and other project drawings in just few minutes using Edificius – the 3D Building Design Software.

Accessible toilet with minim dimensions: A-A cross- section created with Edificius

Accessible door

The door must open or swing outwards and be fitted with a horizontal closing bar fixed to the inside face to make it easier for the user to close the door behind themselves independently. The door opening itself must be a minimum of 90cm wide, but ideally 95cm wide to allow easy access by a wheelchair user.

In the USA, ADA Facilities and elements are required to be identified by using the international symbol of accessibility.

In order to accommodate a wheelchair, doorways should be a minimum of 32″ wide. If the doorway is located in the typical hallway and requires turning a wheelchair, you’ll need a 36″ door.

How to design an accessible toilet: corridors, halls, passageways

Sanitary accommodation for people with disabilities should be provided in a convenient and accessible part of a building to which wheelchair users have independent access. A wheelchair user should not have to travel more than 40m horizontally to reach a suitable toilet.

All walks, halls, corridors, aisles and other passageways should be wide enough to allow people spaces that are part of an accessible route shall comply with ADA, where  the minimum clear width of an accessible route required is  36 in (915 mm) except at doors.

Accessible toilet with minimum dimensions: B-B cross- section created with Edificius

Accessible toilet Water Closet

Disabled toilet heights can vary from 44cm up to 50cm, but they’re most commonly installed at 45cm.

Some wheelchair users find it difficult to use a standard height WC seat and, for them, it is important that the WC pan can accept a variable height toilet seat riser.

In the USA, water closets must be 17 to 19 inches from the floor (43cm to 48.5cm), measured from the floor to the top of the toilet seat. Seats shall not be sprung to return to a lifted position.

Handrails / Grab bars

Grab rails are a basic feature of any accessible toilet. They provide crucial support, stability and balance for anyone transferring onto the toilet.

According to Document M, a unisex wheelchair-accessible toilet or compartment will have four grab rails: two horizontal bars on either side of the WC, two vertical grab rails on either superior side of the basin. When it is a corner WC, one horizontal grab rail is mandatory on the wall next to the WC, whether wall mounted or drop-down. An additional drop-down rail is needed between both when the adjacent grab bar is more than 40cm from the toilet; this would be the case of peninsular WCs. On the open side of this WC, a drop-down rail is normally fixed (32cm from the centre of the toilet).

An ADA-compliant grab bar  must be fully anchored and have a smooth surface that can be easily grabbed. The diameter or width of the gripping surfaces of a handrail or grab bar shall be 1-1/4 in to 1-1/2 in (3.2 cm to 3.8 cm), or the shape shall provide an equivalent gripping surface.  Grab bars must be installed between 34 and 38 inches above the floor, and there must be a separation between the grab bar and the wall surface of at least 1 1/2 inches. Grab bars must have round edges and must return to the wall (or other anchor point) so there are no exposed ends.

Washbasin

Sinks in accessible toilets should be placed at a lower height, making them useable for anyone seated in a wheelchair.

In the UK , any wheelchair-accessible washroom has at least one washbasin with its rim set at 72cm to 74cm above the floor.

Ideally, accessible basins are designed to be either wall hung with space to get underneath, inset (placed onto a counter top), or with a semi-pedestal.

Washbasin taps are either controlled automatically or can be operated using a closed fist, e.g. by lever action. The pipes or traps should not be boxed in to avoid making it difficult for a wheelchair user to get close enough to the sink to use it properly. The sink must have either lever-handle taps or a tap that has a sensor, so that those with impaired dexterity of their hands can still make use of it.

Consider solid-surface lavatory systems with fully integrated sinks at various heights. Only one bowl in a multi-bowl sink needs to offer minimum knee and toe clearances, so these multi-height lavatory systems combine an ADA-compliant sink with higher sinks.

Create your own project cross-section using Edificius – the 3D Building Design Software  and find out how you can address all of these aspects in a highly productive workflow, faster and with increased quality of work.

Mirror

A mirror located either above the wash basin or on the opposite wall to enable people to see themselves in the standing or seated position.

A mirror, of width 40cm and height 100cm, set 60cm above floor, should be provided.

• Bottom Line 600 mm – top edge 1600 mm (located away from washbasin)
• Bottom line 1600 mm (located above washbasin)
• If mirrors cannot be extended down to the upper edge of the washbasin,
  they should be tilted forward

The ADAAG states that mirrors need to be mounted with the bottom edge of the reflecting surface no higher than 40 inches above the floor, with the top edge at a minimum of 74 inches from the floor. A full-length mirror in the restroom fulfills the ADA requirement for mirrors if it’s not possible to mount the mirror at 40 inches above the floor.

Disabled toilet emergency alarm

The room should be fitted with a pull cord activating an assistance alarm.

Rendered cross-section

Ground and Floor surfaces

Ground and floor surfaces along accessible routes and in accessible rooms and spaces including floors, walks, ramps, stairs, and curb ramps, shall be stable, firm, slip-resistant. The flooring should also contrast visually against the walls.

Options for Document M disabled toilet compliant flooring include non-slip vinyl or non-slip floor tiles.

In addition, shiny ceramic tiles and floors should be avoided. They might cause reflection and glare, which may be visually confusing.

Accessible toilet Lock

There should be a lock on the inside operable with a closed fist, and an emergency release facility on the outside.

Locks and other operating devices on accessible doors shall have a shape that is easy to grasp with one hand and does not require tight grasping, tight pinching, or twisting of the wrist to operate. Lever-operated mechanisms, push-type mechanisms, and U-shaped handles are acceptable designs.

ASEAN provisions for the disabled

The development of an APTS (ASEAN Public Toilet Standard) is one of the measures developed within the framework of the ASEAN Tourism Strategic Plan (ATPS) 2011-2015. The ATPS 2011- 2015 engages the ASEAN member states to develop and implement standardized tourism services and it includes standards for accessibility.

According to the APTS application of Universal Design in Public Toilet should be provided in accordance with standards, codes or laws adopted by the local government/authority/entity having jurisdiction. When no requirement there exists, the following general guidelines are recommended.

Accessible route: to be provided which shall be usable by an unassisted wheelchair user. It should extend continuously from the closest street boundary or car parking space to the accessible toilet and be provided with railings. If elevated, it shall have a ramp with railings;

Accessible entrance: a door should be placed that is minimum 80 cm wide. It shall be opened from the inside out or be a sliding door;

Accessible cubicles: the cubicle’s minimum size shall be no less than 1.5 m wide and 2.2 m deep for the whole length. Horizontal handrails shall be fixed at the rear, sidewall adjacent to the toilet bowl and at the opposite side of the toilet bowl (drop down moveable handrail) at a height not exceeding 80 cm above the floor;

Accessible WCs: WCs shall be set between 43 cm and 48 cm above the floor, measured to the top of the seat at the nose of the pan and fitted with a hinged seat no more than 2.54 cm thick unless required otherwise. Suggested side distance of the WC from the wall, not exceeding 50 cm and total distance from the back wall till the nose of the WC 75 cm (Greed, 2007);

Accessible cubicle toilet paper dispensers: toilet paper dispensers should be located on or in the wall adjacent to the side of the toilet bowl. Dispensers should not stick out more than 10 cm into the minimum cubicle dimensions and shall be located to allow the paper to be dispensed within 30 cm of the nose of the toilet bowl and between 43 cm and 70 cm off the floor.

A sensor activated waste bin (hand-free) and sanitary bin with liners should be located at the side of the toilet bowl, within immediate reach;

Accessible cubicle washbasins: washbasins shall be located as close as possible to the WC to allow handicapped people to reach it easily – thus avoiding contact of dirty hands on various surfaces – at a distance that does not to interfere with a person transferring from the wheel chair to the toilet bowl. Washbasins, therefore, should be set at least 110 cm from the nose of the toilet bowl and shall be mounted at a maximum height of approximately 82 cm off the floor to allow wheelchair users to easily perform washing and grooming activities without being disturbed by any fittings and/or fixtures. Washbasins may be installed in counters or be free standing and attached to walls. All interior water supply and drainage piping should be concealed whenever possible;

The colour of the wall tiles for accessible public toilets should adopt strong colour contrast to cater to the needs of the visually impaired.

Fixtures: Cubicles containing WCs should be no less than 90 cm wide and 152.4 cm deep clear of opened doors (see section 1, accessible cubicles and accessible ambulant cubicles for appropriate cubicle dimensions for the disabled and ambulant people). All cubicles should be provided with locks or latches to allow for privacy. Although accessible from the inside only, authorised outside access key access may be necessary in case of emergencies. Cubicle doors and partitions should be tightly fit so as to avoid any openings and without legs to allow for easy cleaning underneath. Cubicle partitions should extend no less than 2 m above the floor level to allow for appropriate privacy and comfort.

How to design an accessible toilet: 3D objects and blocks

Complete your projects with all the elements that you need to designing an accessible toilet. You can download them from our online BIM Objects Library for free.

Download: 3D model

Here is the 3D model produced with Edificius – the 3D Building Design Software that you can download for free.

Download the project 3D BIM model(.edf file format)