Approved Document M: Volume 1 – Dwellings (2015 Edition with 2016 Amendments)
Approved Document M, Volume 1: Dwellings provides statutory guidance for complying with the Building Regulations 2010 in England regarding the accessibility and use of residential buildings. This 2015 edition, which incorporates the 2016 amendments, supports requirements M4(1), M4(2), and M4(3) of Schedule 1 to the regulations. It was issued by HM Government and took effect on 1 October 2015, replacing the previous requirement for sanitary conveniences with a more comprehensive framework for dwelling categories.
The scope of this document is limited to newly erected dwellings and dwellings undergoing material alteration; it specifically does not apply to the extension of a dwelling. The document establishes technical specifications for three categories: Category 1: Visitable dwellings, Category 2: Accessible and adaptable dwellings, and Category 3: Wheelchair user dwellings. It governs various regulatory domains, including approach routes, car parking, communal and private entrances, internal circulation, sanitary facilities, and the placement of services and controls. It references specific standards such as BS EN 81-70 for passenger lifts and BS 5900 for home lifts.
This structured reference guide details the mandatory and optional requirements that architects, developers, and building control bodies must follow to ensure compliance. It includes precise measurements for door widths, ramp gradients, and clear access zones required for different levels of physical ability and wheelchair usage.
Classification of Dwelling Categories
The document divides accessibility requirements into three distinct categories, each with varying levels of performance and application limits:
- M4(1) Category 1: Visitable dwellings is the mandatory minimum for all new dwellings. It ensures that most people, including some wheelchair users, can approach and enter the dwelling and access habitable rooms and a WC on the entrance storey.
- M4(2) Category 2: Accessible and adaptable dwellings is an optional requirement that applies only when specified by a planning condition. It provides a higher level of accessibility and allows for future adaptation to meet the changing needs of occupants.
- M4(3) Category 3: Wheelchair user dwellings is an optional requirement for dwellings specifically designed for wheelchair users. It is divided into wheelchair adaptable (M4(3)(2)(a)) and wheelchair accessible (M4(3)(2)(b)).
External Approach and Entrances
Guidance for the approach route to a dwelling varies by category but focuses on providing a safe and convenient path from the point of access (such as a car parking space) to the entrance.
- Approach Routes: For Category 1, the route should have a minimum width of 900mm and a maximum cross fall of 1 in 40. For Category 3, the minimum width increases to 1200mm.
- Ramps: Gradient requirements for ramps are defined by flight length; for example, a 1:12 gradient is limited to a 5m flight, while a 1:20 gradient can extend to 10m.
- Communal Entrances: Principal communal doors must have a minimum clear opening width of 775mm for Category 1 and 850mm for Categories 2 and 3.
- Accessible Thresholds: All principal entrances must have a threshold with a total height of no more than 15mm to facilitate wheelchair passage.
Internal Circulation and Doorways
Internal layouts must allow for unobstructed movement between habitable rooms and sanitary facilities. Requirements are specified for clear opening widths based on the direction of approach.
- Door Widths: In Category 1 dwellings, a door approached head-on from a 900mm corridor must have a minimum clear opening of 750mm. If the approach is not head-on, the required width increases.
- Localised Obstructions: Items such as radiators must not reduce corridor widths below 750mm (Category 1) or 1050mm (Category 3).
- Manoeuvring Space: Category 3 dwellings require a 1500mm clear turning circle inside the entrance area and within every habitable room.
Sanitary Facilities
The document provides detailed layouts and clearance zones for WCs, bathrooms, and cloakrooms to ensure they are usable by persons with reduced mobility.
- Entrance Storey WC: All dwellings must provide a WC on the entrance storey (or principal storey if no habitable rooms are on the entrance level).
- Category 2 Bathrooms: Walls must be strong enough to support the future installation of grab rails and seats, capable of withstanding a load of 1.5kN/m².
- Category 3 Wet Rooms: Every room containing an installed level access shower must be constructed as a wet room.
Services and Controls
To assist occupants with reduced reach, the document specifies the mounting heights for various electrical and mechanical controls.
- Switches and Sockets: Centre lines for light switches, power sockets, and TV aerial jacks must be between 450mm and 1200mm above floor level in habitable rooms.
- Consumer Units: Switches on consumer units should be mounted between 1350mm and 1450mm above floor level.
- Window Handles: In Category 3 dwellings, at least one window in the principal living area must have a handle located between 700mm and 1000mm above floor level.
Frequently Asked Questions
Is Requirement M4(1) mandatory for all dwellings?
Yes, M4(1) Visitable dwellings is mandatory for all new dwellings unless a local planning authority imposes the optional requirements M4(2) or M4(3) as a condition of planning permission.
Does Approved Document M Volume 1 apply to building extensions?
No, the requirements of this approved document do not apply to the extension of an existing dwelling.
What is the difference between wheelchair adaptable and wheelchair accessible dwellings?
A wheelchair adaptable dwelling (Category 3) is designed to be easily altered to meet a wheelchair user's needs in the future, whereas a wheelchair accessible dwelling is constructed to be suitable for immediate occupation by a wheelchair user at completion.
What is the minimum clear opening width for a dwelling's principal private entrance?
For Category 1 dwellings, the minimum clear opening width is 775mm. For Category 2 and Category 3 dwellings, this increases to 850mm.
What is an 'accessible threshold' according to the Building Regulations?
It is a threshold that is level or, if raised, has a total height of not more than 15mm, with any upstands higher than 5mm being chamfered.
What are the load-bearing requirements for bathroom walls in Category 2 dwellings?
Walls, ducts, and boxings must be strong enough to support grab rails or seats that impose a load of up to 1.5kN/m².
Are there specific height requirements for light switches in new homes?
Yes, switches in habitable rooms must have their centre line between 450mm and 1200mm above floor level to assist people with reduced reach.
What is the required width for a corridor in a Category 2 dwelling?
The minimum clear width of every hall or landing in a Category 2 dwelling is 900mm, which may be reduced to 750mm at localised obstructions like radiators.
