Approved Document M explained

What is Approved Document M?

Approved Document M is the statutory guidance on Part M of the Building Regulations 2010, which requires reasonable provision for people to gain access to and use buildings and their facilities in England. Volume 1 covers dwellings and the access categories M4(1), M4(2) and M4(3); Volume 2 covers buildings other than dwellings under requirements M1 to M3.

Part M sits in Schedule 1 to the Building Regulations 2010. For buildings other than dwellings, M1 says reasonable provision must be made for people to gain access to and use the building and its facilities. M2 covers access to extensions to buildings other than dwellings, and M3 covers sanitary conveniences in those extensions.

For dwellings the structure is different. M4(1) is the baseline "visitable dwelling" standard. M4(2) and M4(3) are higher, optional requirements that only apply when planning permission says so.

The editions have not changed for some time. Volume 1 is the 2015 edition incorporating 2016 amendments, which took effect on 1 March 2016. Volume 2 is the 2015 edition incorporating 2020 and 2024 amendments. Both are published on GOV.UK. What has changed is the policy around them.

Volume 1 vs Volume 2

Volume 1 applies to newly erected dwellings and dwellings undergoing material alteration. Volume 2 applies to new non-domestic buildings, extensions to them and certain material changes of use.

Volume 1 does not apply to house extensions; requirement M4(1) expressly excludes them. An extension should not make the existing dwelling less compliant with Part M than it was before.

What are M4(1), M4(2) and M4(3)?

Volume 1 sets three categories of dwelling, and any one dwelling is assessed against only one of them. M4(1) is the default; M4(2) and M4(3) substitute for it on new build homes when a planning condition applies them.

M4(2): accessible and adaptable dwellings

The provision must be sufficient to "meet the needs of occupants with differing needs, including some older or disabled people" and "allow adaptation of the dwelling to meet the changing needs of occupants over time". It can only apply to dwellings that are erected.

M4(3): wheelchair user dwellings

M4(3) has two variants. M4(3)(2)(a) wheelchair adaptable allows simple adaptation of the dwelling to meet the needs of occupants who use wheelchairs, and applies by default where M4(3) is triggered and the permission does not say otherwise. M4(3)(2)(b) wheelchair accessible meets those needs from the outset, and applies only where the planning permission specifically requires it.

If the client expects fully wheelchair accessible homes, the condition has to say M4(3)(2)(b). Otherwise the default is adaptable.

How planning permission triggers M4(2) and M4(3)

Volume 1 is explicit: an optional requirement "only applies where a condition that one or more dwellings should meet the relevant optional requirement is imposed on new development as part of the process of granting planning permission". Without that condition, M4(1) applies.

What to do when a condition applies

• ✓The decision notice has been read, and each condition's category and variant is recorded.
• ✓Building control has been told which optional requirements apply (Volume 1, para 0.6).
• ✓Categories are mapped to plots early, since mixing M4(2) and M4(3) affects cores, lifts, parking and unit mix.
• ✓The category is recorded against each plot in the drawings and specifications.

Is M4(2) becoming the mandatory default?

Not through the Building Regulations, at least for now. In October 2026, M4(2) and M4(3) remain optional requirements triggered by planning conditions, but the August 2026 NPPF expects local plans to require at least 40% M4(2) on major developments.

In July 2022, after its "Raising accessibility standards for new homes" consultation, the government said it would mandate M4(2) in the Building Regulations as the minimum for all new homes, with M4(1) by exception, subject to a further consultation on the technical details. That consultation was not published. The current government used planning policy instead.

Policy HO5 of the revised NPPF says plans should set out the proportion of housing on major developments to be delivered to M4(2) and M4(3), that requirements should meet or exceed local need, and that "no less than 40% of homes on major developments are delivered to M4(2) standards (subject to any appropriate exemptions set out in the development plan)". It sets no national minimum for M4(3), which is left to local plans based on evidence of need.

Conditions applying M4(2) will therefore become more common. Many authorities already require far more than 40%, and London Plan policy has long required 90% M4(2) and 10% M4(3) on new-build housing. Check the adopted development plan for each site.

Buildings other than dwellings

Volume 2 covers the full journey: from the site boundary and parking to the entrance, through horizontal and vertical circulation, to sanitary accommodation, audience seating and hotel bedrooms.

Some figures architects check most often:

• Entrance doors: a minimum effective clear width of 1000mm for external doors to buildings used by the general public.
• Extensions (M2 and M3): a non-domestic extension should be treated as a new building for Part M purposes, with independent access where reasonably practicable.
• Material changes of use: regulation 6 brings Part M into play when an existing building changes to uses such as a hotel or boarding house, institution, public building or shop.

Changing Places toilets

The 2020 amendments to Volume 2, in force from 1 January 2021, require Changing Places toilets in new buildings and certain extensions and changes of use above set thresholds. These include assembly, recreation and entertainment buildings with a capacity of 350 or more, shopping centres and retail parks of 30,000m² or more, sport and leisure buildings over 5000m², hospitals and primary care centres, and libraries and university buildings open to the public.

Part T and the 2024 amendments

The 2024 amendments to Volume 2 are consequential changes linked to Part T (toilet accommodation), in force from 1 October 2024. Requirement T1 asks for reasonable provision of single-sex toilets in buildings other than dwellings, with universal toilets where space precludes single-sex provision. Read Approved Document T alongside Volume 2 for any non-domestic toilet layout.

Where Part M meets Part K

Approved Document K covers stairs, ramps and guarding for safety, while Approved Document M covers them for accessibility, and both apply. External stepped access at principal entrances is a common place where the two need to be read together.

Where Avoice fits

M4(2) and M4(3) requirements are scattered between planning conditions, local plan policies and Volume 1, which is where errors creep in.

Avoice Regulations holds the full Approved Document M, both volumes, as a searchable library, with answers that cite whether they come from the Building Regulations or the Approved Document. Inside Avoice Practice, the Planning Conditions tracker logs which plots carry M4(2) or M4(3) conditions, and the Building Regs Tracker records how Part M compliance is evidenced.

Software can retrieve, compare and flag. The architect, the planning authority and building control still decide what each dwelling requires.