EPISODE: 029 - APPROVED DOCUMENT M - ACCESS TO AND USE OF BUILDINGS - VOLUME 1
- Piotr Bytnar BEng (Hons) MSc CEng MIStructE
- Nov 5, 2024
- 30 min read
Updated: Jun 25, 2025
BYTNAR - TALKS
EPISODE 029 - APPROVED DOCUMENT M - ACCESS TO AND USE OF BUILDINGS - VOLUME 1
This episode is for people who want to know more about Approved Document Part M – Access to and Use of Buildings– Volume 1 – Dwellings.
You should like this episode if you ask yourself questions like:
What are the categories of dwellings defined in Approved Document M for accessibility?
What are the specific requirements for visitable dwellings (M4(1)) under Approved Document M?
How should approaches to dwellings be designed to ensure accessibility for disabled visitors?
What modifications can be made to accessible and adaptable dwellings (M4(2)) to meet future needs?
What standards must wheelchair user dwellings (M4(3)) meet in terms of accessibility and adaptability?
What are the minimum width requirements for doorways and corridors in accessible dwellings?
How can electrical fixtures be made accessible in new dwellings according to Approved Document M?
What design features support step-free access in both public and private areas of a dwelling?
What considerations should be made for communal entrances to ensure accessibility for all users?
This is Bytnar Talks: The Engineer Takes on Construction, Episode 29.
Hi, I'm Piotr Bytnar. Each day I help my clients plan and design building projects through Bytnar Limited, a consulting Chartered Structural Engineers practice. My biggest passion, and the cornerstone on which I've built my business, is finding clever solutions for construction projects.
I am a Chartered Structural Engineer and a budding software developer, so you can rest assured that I will strive to talk about the best practices and the use of new technologies in the industry. And if you're embarking on a construction project, or are involved in planning, designing, and building the world around us, you'll find this podcast useful.
Approved Document M – Access to and Use of Buildings, Volume One: Dwellings
Hi, and welcome to Bytnar Talks, your favorite podcast on all matters of architecture, engineering, and construction.
It is Friday, the 20th of September 2024, and I'm here back with you with the 29th episode and information on Approved Document M – Access to and Use of Buildings, Volume One: Dwellings.
It’s been quite a busy month thus far – planning applications, building control applications, structural designs, detailing of steel structures, reports, meetings, networking, and most of all, making preparations for Kent Construction Expo, which will be held at Maidstone Detling Showground on the 4th of October – so in less than two weeks really.
Bear with me with that patchy delivery, but hey, where else can you listen to what is included in building regulations? Anywhere else than here? I doubt so.
If you are visiting this year, come to stand 365 for a chat – 365 days a year, we stand in your corner.
The last episode was another long one, so I hope to recap this one quickly and move forward to the one of today.
In the last episode, I talked about the first volume of Approved Document L: Conservation of Fuel and Power dealing with buildings other than dwellings. These requirements are contained within two L requirements and 17 additional regulations covered in 12 sections of the document.
Section Zero is the introduction, which overlaps with Volume One, with distinctions for different building types and stages of execution like shell and core, modular construction. And then, when we get to the second thing in that shell and core, it also covers exemptions for specific buildings and notes the necessity of integrating this document with other building regulations.
Section One details the calculation of target primary energy and emission rates using standard specifications for a notional building. The results must be compared with as-designed and as-built rates and communicated to building control.
Section Two focuses on calculating the building's actual primary energy and emission rates, stressing the accuracy of as-built calculations, particularly with multiple fuel sources. Special attention is given to district heating systems and system management improvements.
Section Three tells us about the mandatory assessment of high-efficiency alternative systems, requiring reports on their technical, environmental, and economic feasibility. These reports provide insight for building control authorities and pose insight into possible upgrades.
Section Four covers fabric performance regarding heat gains and losses, setting specific U-value limits for building elements. It concentrates on minimizing thermal bridging, maximizing air tightness, and minimizing solar gains while addressing insulation and energy loss in the running of services.
Section Five establishes minimum efficiency standards for building services, ensuring new and replacement systems meet regulatory requirements. The section stresses proper sizing, control, and maintenance of systems, along with the need for energy meters for accurate monitoring.
Section Six outlines energy efficiency requirements for various building systems such as boilers, heat pumps, and ventilation. Efficiency standards vary based on fuel type and system capacity, with guidance on control systems and technologies like combined heat and power (CHPs) and lighting.
Section Seven sets air permeability standard at 8 cubic metres per hour per metre squared at 50 pascals and provides guidelines for testing and exceptions. Testing must be conducted by qualified personnel, and specific requirements apply to complex buildings. Results need to be submitted to building control.
Section Eight requires commissioning of fixed building services to ensure energy-efficient operation, aligned with CIBSE’s Commissioning Code M. A commissioning plan and notification of completion must be submitted to Building Control, documenting any deviations from expected performance.
Section Nine mandates the provision of a building logbook in line with CIBSE's TM31, detailing energy-efficient operations, maintenance, and commissioning records. Large buildings over 1,000 m² must include an energy use forecast, with logbook updates required after system modifications.
Section Ten tells us about new elements in existing buildings, which must meet current energy performance standards. Extensions over 100 m² are treated as new builds. Compliance can be demonstrated through area-weighted U-values, calculations, or approved calculation methods.
Section Eleven deals with renovations or material changes affecting energy use that must improve thermal performance to meet specific U-values. Significant renovations involving over 50% of an element’s surface require upgrades to the entire element.
Section Twelve tells us that for buildings over 1,000 m² undergoing extensions or significant system upgrades, those significant system upgrades must include consequential improvements to enhance energy performance. These improvements must be feasible and involve a minimum spend of 10% of the principal works’ costs.
In this episode, I will move to Approved Document M: Access to and Use of Buildings, Volume One – Dwellings. So, without further ado, let's dive straight into it. [Music]
In this episode, I will talk about the statutory guidance contained within Approved Document M: Access to and Use of Buildings, Volume One – Dwellings. The requirements of Part M are contained within four parts, but only Part Four is applicable to dwellings.
I will therefore start by reading you the Requirement M4 paragraphs and then move on to what is covered in the approved document. The episode will follow the structure of previous episodes dealing with approved documents: first, the text of legislation, then Sections 0, 1, 2, and 3.
So let’s get into the nitty-gritty of this approved document.
Alright, guys – starting with the text of the legislation:
Access to and Use of Dwellings
Category 1 – Visitable DwellingsRequirement M4(1)
Reasonable provision must be made for people to:
(a) gain access to; and
(b) use the dwelling and its facilities.
Category 2 – Accessible and Adaptable DwellingsRequirement M4(2) – Optional Requirement
Reasonable provision must be made for people to:
(a) gain access to; and
(b) use the dwelling and its facilities.
The provision made must be sufficient to:
(a) meet the needs of occupants with different needs, including some older or disabled people; and
(b) allow adaptation of the dwelling to meet the changing needs of occupants over time.
Category 3 – Wheelchair User DwellingsRequirement M4(3) – Optional Requirement
Reasonable provision must be made for people to:
(a) gain access to; and
(b) use the dwelling and its facilities.
The provision made must be sufficient to:
(a) allow simple adaptation of the dwelling to meet the needs of occupants who use wheelchairs; or
(b) meet the needs of occupants who use wheelchairs.
Requirement M4(1) does not apply to:
(a) an extension to a dwelling; or
(b) any part of a building that is used solely to enable the building, or any service or fitting in the building, to be inspected, repaired, or maintained.
Optional Requirement M4(2):
(a) may apply only in relation to a dwelling that is erected;
(b) will apply in substitution for Requirement M4(1);
(c) does not apply where Optional Requirement M4(3) applies;
(d) does not apply to any part of a building that is used solely to enable the building, or any service or fitting in the building, to be inspected, repaired, or maintained.
Optional Requirement M4(3):
(a) may apply only in relation to a dwelling that is erected;
(b) will apply in substitution for Requirement M4(1);
(c) does not apply where Optional Requirement M4(2) applies;
(d) does not apply to any part of a building that is used solely to enable the building, or any service or fitting in the building, to be inspected, repaired, or maintained.
Optional Requirement M4(3), point 2(b) applies only where the planning permission under which the building work is carried out specifies it shall be complied with.
So – simples, isn’t it?It will usually be only Requirement M4(1) that we need to observe, unless otherwise stipulated by the planning permission. As ever, the document starts with an introduction, contained within Section 0.
The document is divided into three sections, covering:
Visitable dwellings,
Accessible and adaptable dwellings, and
Wheelchair user dwellings.
The recommendations of this document do not apply to extensions, but only to new dwellings and dwellings undergoing material alteration.
We are obliged to inform Building Control if there are any optional requirements attached to the planning permission, and to which dwelling they apply. If stated in the planning approval, the access to the dwelling should follow the optional requirements when applicable.
Mixed-use buildings will need to follow the recommendations of Volume Two for the common areas, and we may also need to check the Workplace Regulations and the Equality Act to satisfy the letter of law.
As ever, when undergoing material alteration, the building cannot be worse off than it was before. And for historic buildings, adaptability should be balanced with historical merit.
We are also informed that Part M takes precedence over Part K requirements. But when we are to make the approach to the building more convenient by a ramp or level access, we should also mind Requirement C.
Section 1 deals with Category 1: Visitable Dwellings, The Secretary of State is satisfied that the dwelling or dwellings can be reasonably accessed by a disabled person who can walk from the likely highlighting (→ drop-off) point or from the car.
A toilet is available at the entry storey if there is a habitable room at this storey, or otherwise on the principal storey. Bathroom access from the habitable room at the entry storey should be step-free.
Wall-mounted switches and socket outlets in habitable rooms should be accessible to people with reduced reach.
Section 1 is divided into Part A and Part B, dealing with:
The approach to the dwelling and private entrances
Spaces within the dwellings, consecutively.
Section 1A applies to the external and internal areas within the curtilage of the dwelling or the development. If car parking does not form part of the curtilage, the whole idea is for a person to reach the dwelling safely after leaving a car.
The approach should be:
At least 900 mm wide,
Unobtrusive, gentle, firm, not slippery,
And only stepped if unavoidable.
Cross fall: maximum of 1 in 40 gradient.
If the external approach needs to be ramped:
An individual flight needs to be no longer than 10 m for a gradient up to 1 in 15,
And no more than 5 m for a gradient of 1 in 12.
Width: at least 900 mm, with landings at top and bottom and at turns between flights of at least 1200 mm long.
If the approach is external and stepped:
It needs to be a minimum of 900 mm wide,
With landings of at least 900 mm length every 1.8 m rise,
Have suitable nosings, and
Minimum tread of 200 mm with risers between 75 and 150 mm – conveniently resembling brick thicknesses.
One-sided grippable handrail needs to be put in place whenever the change in level includes at least three risers.
The handrail needs to extend 300 mm past the top and bottom nosings
And be at a height of between 850 mm and 1 m.
Communal entrances:
Should be at least 775 mm wide
And easy to traverse by a wheelchair.
Communal lift should be provided whenever possible, and should be suitable for wheelchair use.
It must have a landing of at least 1.5 m by 1.5 m in front of the lift door,
Load capacity of at least 400 kg,
Doors opening at least 800 mm,
Car space of at least 900 mm by 1250 mm,
Controls placed at least 400 mm away from the inside of the front wall,
At a height between 900 mm and 1200 mm,
Have tactile indicators outside and inside,
And signal that it works when we press the button.
If it serves more than three floors, it should inform us visually and audibly about the reached storey.
It should remain open for at least 5 seconds,
And have an override button working for 3 seconds.
The document says that lifts to BS EN 81-70 Type 1 specification will satisfy the requirement.
Communal stairs should meet Requirement K for general access stairs if there is no lift and be at least of a utility type in line with Requirement K when a lift is present.
Section 1B regulates private entrances and spaces within the dwelling.
The entrance should be level and traversable by a wheelchair whenever possible, and be step-free whenever possible.
If steps are present, they should be of maximum 150 mm rise and aligned with the threshold. The clear opening remains at 775 mm.
Circulation areas and internal doorways should be between 750 and 800 mm minimum width, depending on the nature of the access to the door—less when the access is head-on, and more otherwise.
Corridors, in similar fashion, should be between 900 mm and 1200 mm, but not less than 750 mm at localized obstructions (like radiators). These obstructions cannot be opposite doors and should be no longer than 2 m—(2 mm would be quite small!).
Steps between the habitable rooms at the entrance storey should be avoided whenever possible.
Water closet facilities should be provided on the entrance storey, where there are habitable rooms—or on the primary storey, otherwise. There should be sufficient space in the WC facility:
At least 450 mm either side of the centre line of the toilet,
And 750 mm to the front of the water closet.
For the basin, it can be a bit less: 400 mm to one side if access is oblique.
Doors should open outwards, and generally the minimum dimensions are:
Around 1500 mm for frontal access,
1600 mm for oblique access.
Doors opening can infringe on the water closet basin by as much as 250 mm, and similarly, the sink can intrude with its trap into the edge of the 750 mm zone.
For ease of operation of switches, sockets, bells, etc., these should be placed within a zone between 450 mm and 1200 mm above the floor.
Consumer units should be installed at 1350 mm to 1450 mm height.
So, that is the simple and most common set of requirements.
Now we will move to Optional Requirement M4(2): Category 2 Dwellings, where considerations are pretty much the same, but the dimensions and features of the dwellings are more suitable for people with a wider range of mobility issues, and the building is primed for future functionality and accessibility upgrades.
Section 2A follows the same scope of considerations as Section 1.
Circulation and access areas need to be sufficient for the purpose,
The approach needs to be step-free and as gentle as possible.
But if the principal private entrance cannot be reached without stairs, a suitable alternative step-free access to the dwelling needs to be provided.
If the approach is communal and rises by at least 300 mm, there should also be a stepped access available.
Private approaches should be 900 mm wide generally, but can be down to 750 mm, taking into consideration localized obstructions.
Communal parts with dimensions extend to 1200 mm and 1500 mm wide, respectively.
Naturally, the ground surface needs to be suitable, and any gates on the route should have a minimum clear opening width of 850 mm, with a 300 mm nib to the leading edge of the gate to allow for easy operation.
The document gives us provisions for the length of ramps depending on the gradient, starting with as little as 2 m for the steepest gradient of 1 in 12, up to 10 m for 1 in 20.
Here again, the width of the flight will depend on whether it is a private or communal ramp, and will be either 900 mm or 1200 mm.
Landing requirements remain as before—needed at the top, bottom, between flights, and at changes of direction—of at least 1200 mm in length.
Stairs forming an additional route should be uniform, with:
Rises between 150 mm and 170 mm,
Goings between 280 mm and 425 mm,
Steps with suitable nosings, at least 900 mm wide,
And landings.
Stairs should have a handrail of suitable dimensions, typically 850 to 1000 mm in height, on at least one side for stairs not wider than 1 m.
Handrails should extend 300 mm past the top and bottom nosings.
Parking spaces, when provided in a private setting, should be capable of accommodating at least one space of 3.3 m width.
Communal parking spaces for blocks of flats should have at least one parking place close to the entrance, with:
A 900 mm wide clear access zone to one side,
Dropped kerb,
And all features to make it easy to use: suitable surface, level or shallow gradient approach, and step-free access to the building.
Drop-off points follow similar expectations in terms of:
Surface,
Step-free character,
Being as level as possible,
Located close to the entry point.
Where a dropped kerb is present, it should be at least 1 m wide, with a slope of no more than 1 in 12.
Communal entrances need to be covered, with a minimum width of 1200 mm and depth of 900 mm, and be formed by a landing of at least 1.5 m × 1.5 m, clear of the swing of any door and be automatically illuminated with fully diffused light by dusk-till-dawn lighting.
Doors or gates should have at least 850 mm clear opening. Like previously, we need to think about the space on both sides of the doors to provide easy access. This can be achieved by a nib at least 300 mm wide to the leading edge, creating a space around the swing of the door of at least 1200 mm, and a 200 mm reveal maximum.
In the case of porches or lobbies, the doors should be at least 1.2 m apart and should not swing against each other.
An accessible threshold is a must. A surface of proper quality is required.
Door controls should be between 900 mm to 1 m above the floor, and at least 300 mm away from any projecting corner.
All remaining communal doors on the way should meet these provisions—except those for external parts of such doors.
Communal lifts should have a landing of 1.5 m × 1.5 m in front of the doors.Lift type 2 to BS EN 81-70 is said to be sufficient. The car needs to be a minimum of 1.1 m wide and 1.4 m deep to allow for a wheelchair user.
Minimum door opening: 800 mm.Controls: between 900 mm and 1200 mm above the car floor, and a minimum of 400 mm away from the inside of the front wall.Dwell time: at least 5 seconds.
Communal stairs should meet the general access stair requirements of Requirement K.
Section 2B now deals with private entrances and space within the dwelling, that includes other external doors and key elements within the dwelling.
Principal private entrances—and alternative entrances where step-free access cannot be achieved to the principal entrance—should have a covered landing.
The landing should be at least 1.2 m × 1.2 m, and the covering should be at least 900 mm wide and 600 mm deep.
Lighting should be diffused and work from dusk till dawn.Door openings should be at least 850 mm clear width. If doors are double, the leading leaf should maintain that dimension.
The 300 mm nib, creating space of at least 1200 mm, and the maximum 200 mm reveal, is also applicable here.
Accessible threshold and at least 1500 mm of clear space between the doors of porches or lobbies is also a must.
The same requirements (except for landings) are also applicable to all other doors associated with the dwelling.
Circulation areas now need to be either:
At least 900 mm wide for halls, landings,
And not less than 750 mm at points of obstructions.
Obstructions can be a maximum of 2 m in length and are restricted to areas away from doors.
A 1.5 m obstruction-free zone is required at doors opening for uninterrupted maneuvering, and 300 mm is the minimum distance at corners, including for the nib at the entrance storey.
The nib needs to extend by at least 800 mm in such cases.
Door clear width will depend on the corridor space and the way we approach it—head-on, and if the corridor is at least 1200 mm wide, the clear opening can be as low as 750 mm; extending to 800 mm where the corridor is 900 mm wide, and the approach is oblique.
Private stairs and changes of level are rather straightforward.
There shall be no obstruction to the use of rooms and facilities at the entrance storey,
And this should be avoided wherever possible on other storeys.
To be able to fit a stairlift, the stair needs to be:
At least 850 mm wide,
With 450 mm above the pitch line of the stairs, including the newel post,
And meet K requirements.
Living, kitchen, and eating areas should be usable and easy to access.
There should be a living area at the entrance storey, which may be a living room, dining room, or kitchen-diner.
To move freely, there should be at least 1200 mm clear space in front of kitchen units and appliances.
Glazing to a principal window of the principal living area should start at a maximum height of 850 mm above floor level,or at the minimum height compliant with the requirements of Part K for guarding to windows.
The bedroom should also be accessible and allow at least 750 mm wide route from the door to the window.
There should be at least one double bedroom with 750 mm clearance on all sides of the bed except the headrest.
All single and twin bedrooms should provide 750 mm clear width to one side of each bed.
One way to show compliance is to provide dimensioned drawings using the figures listed in Appendix D of the document.
It is fine to have a bedside table, as long as it is not deeper than 600 mm from the wall.
Sanitary facilities also have provisions for more accessible use. Water closets, cloakrooms, bathrooms, and shower rooms—walls, ducts, and boxings—should be strong enough to support grab rails, seats, and other adaptations up to 150 kg per m².
Water closets on the entrance storey should provide step-free access, and perhaps showering facilities.
For some wheelchair users all dwellings should have a room containing a WC and basin, with doors opening outwards in all such circumstances.
In two- or three-storey dwellings with one or two bedrooms, the water closet should follow the recommendations of Category 1 dwelling.
However, when there are three or more bedrooms, we need to think about the provision of a level-access shower and the dimensions of clear zones that will allow use of the room by less mobile people.
The minimum dimensions of the zones are given by the document. We generally think about the movement of a 1100 mm long by 700 mm wide wheelchair in and out of spaces and around the rooms.
If there is an accessible toilet on the entrance storey, as well as a water closet cloakroom, the water closet may comply with the requirements of Category 1 dwelling.
Similarly, for bathrooms, the document gives us clearances for layouts. It tells us that on the storey with the double bedroom (a.k.a. principal bedroom), there should be a bathroom containing a water closet, a basin, and a bath.
We should note that if there are no other rooms in the house with potential for a level-access shower, this should be considered for that bathroom.
Services and controls need to be conveniently placed for people with reduced reach:
Consumer units at 1350 mm to 1450 mm height,
Switches, sockets, stops, and controls at 450 mm to 1200 mm, and at least 300 mm away from internal corners,
Window handles in a principal living area should be placed between 450 mm to 1200 mm above floor level, or operated by remote switch at the same level.
All other windows:
Operable controls should be within the same range unless glazing height exceeds 1400 mm above floor level.
Boilers and other controllers should generally be positioned between 900 mm and 1200 mm,except for radiators or cooker hoods.
Section 3 deals with Category 3 dwellings, which are wheelchair user friendly, but otherwise follow the same considerations we've already covered in Category 1 and 2 houses.
Section 3A goes on to tell us about the approach to the dwelling—similar to the previous sections.We address the access to the dwelling from outside, including from the drop-off point.
Naturally, the route needs to be convenient for the wheelchair user, meaning:
No steps,
Good surface,
And it should include step-free mobility scooter parking, if such is provided.
If the approach is communal and rises over 300 mm,we are obliged to provide a step-free alternative route.
The approach route should be at least 1200 mm wide.Any localized obstructions should be no longer than 2 m and should not occur at changes of direction, or opposite or near doorways.
We need to provide 1.2 m × 1.2 m width and depth spaces for turning and passing, placed at a maximum of 10 m apart.
External approaches should be lit with diffused light from dusk till dawn.
Any gate between the footway and the main communal or private entrance should have:
A minimum 850 mm clear opening,
A 300 mm nib to the leading edge,
And a 200 mm nib to the trailing edge.
External and internal ramps should have gradients between 1 in 20 to 1 in 15:
Up to 10 m length for 1 in 20,
5 m length for 1 in 15.
Landings, as necessary, should be provided in addition to the top, bottom, and change of direction, and need to be at least 1200 mm long.
For additional stepped routes, the steps should:
Be between 150 mm and 170 mm rise,
And 280 mm to 425 mm going.
Maximum flights remain at 1.8 m rise, with:
Nosings of minimum 900 mm clear width,
Landings minimum 900 mm long,
And railings for all flights of three steps or more.
Single steps should be avoided.
A grippable handrail should be positioned:
At a height of between 800 mm and 1000 mm,
And extend beyond top and bottom nosings by at least 300 mm.
Car parking and drop-off points should allow the wheelchair user to be mobile around the car.
Parking spaces must have enough clearance on both sides to allow wheelchair users to transfer and access the boot.
In a communal setting, access is to one side and the boot.
In a private setting, full access should be allowed.
The surface should be firm, level, and stable, with a minimum overhead clearance of 2.2 m.
Space can be shared between parking places.
The drop-off point should be level, with a good surface, and dropped kerbs should not be too steep—1 in 15 maximum—and at least 1 m wide, and reasonably flush with the ground.
Communal entrances should be covered, with a minimum of 1.2 m × 1.2 m canopy, and have a 1.5 m × 1.5 m landing. A 1.5 m turning circle behind the closed doors is required.
They must be well-lit with diffused lighting from dusk till dawn, either switched on automatically during dark hours or motion-activated when approached.
The clear 850 mm opening applies here also to the leading door edge. 300 mm nibs are naturally extended for at least 1800 mm, and a 200 mm nib is also required on the following edge.Also, the 200 mm maximum reveal to the leading edge applies here.
The threshold must be of an accessible type, and there should be at least 1500 mm of space between door swings in case of porches and lobbies.
The ground surface should not impede wheelchair users, and we need to provide power assistance if doors require too much force to open.
The document limits this force to:
30 Newtons from 0° to 30° of opening,
Then 22.5 Newtons from 30° to 60°.
Controls for such doors should be 900 mm to 1 m above floor level, and at least 300 mm away from any projecting corner.
All other communal doors should follow these requirements as well,except for the ones dealing with external approaches, where there’s no need for a canopy.
Communal lifts are generally acceptable if they follow BS EN 81-70 Type 2 specification. Otherwise:
The landing in front of lift doors should be at least 1.5 m × 1.5 m,
The lift car should be 1100 mm wide by 1400 mm deep,
Doors must have a clear opening of at least 800 mm,
Landing and car controls should be 900 mm to 1200 mm high above the floor,
And at least 400 mm from the inside of the front wall.
Dwell time remains at 5 seconds.
Communal stairs should follow Requirement K for general access stairs.
Now we move on to Section 3B, which deals with private entrances and spaces within and connected to the dwelling.
To show compliance with the spatial and functional provisions for wheelchair-adaptable or accessible dwellings, we are obliged to demonstrate this through dimensioned and furnished layouts, to a scale of 1:100 at least.Furniture sizes are provided in the document in Appendix D.
Private entrances should be suitable for wheelchair use, which will generally mean:
A level external landing of 1.5 m × 1.5 m,
Clear of door swings,
Lit with diffused light when needed.
We also need to consider the turning circle inside the door swing, of at least 1.5 m diameter when the doors are closed.
A typical 300 mm nib, creating a niche of at least 1800 mm, needs to be provided at the leading edge of the doors,and at least 150 mm on the hinge side to allow for the installation of a cage for the letterbox.
The door clear opening is to be maintained at 850 mm.A 200 mm nib needs to be provided on the approach side of the doors and maintained for 1500 mm.The maximum 200 mm reveal at the leading edge of the doors needs to be assured,as does the 1500 mm space between door swings in porch or lobby-type arrangements.
There are a few more requirements that are depicted quite nicely in the document’s diagrams.
The document also informs us that all other entrance doors will need to meet these requirements,excluding those for the external primary entrance approach (e.g., canopies and landings, etc.).
Hallways and door widths are to be a minimum of 1050 mm wide, unless not approached head-on,in which case they need to be at least 1200 mm wide.
Obstructions cannot occur:
Opposite doors,
Near doors, or
At corners,
and must not be longer than 2 m,
reducing the clear width to a minimum of 900 mm.
All doors must now have a uniform 850 mm clear opening, irrespective of their position.All doors need to have:
A 300 mm leading edge nib,
A 200 mm trailing edge nib,
And be at least 800 mm away from a corner on the leading edge,
or be capable of providing a 1.5 m turning circle between the door and the opposite edge.
We now need to provide wheelchair storage and transfer space between the home and the outdoor wheelchair.
The space should be a minimum of 1100 mm depth and 1700 mm width,
With a space of at least 1200 mm in front of it.
A power socket should be provided to charge the wheelchair.
In the case of an adaptable home, this space can be used for other purposes,provided that no structural works or services relocation would be needed if converted in future. The point of adaptation or reduction of storage space below the required minimums.
This requirement is general for any adaptable parts of the dwelling.We can use it for other purposes, but it should be readily available for adaptation once needed.
General storage provision requirements start at:
1.5 m² for a one-bedroom dwelling,
Up to 4 m² for a six-bedroom dwelling,
Increasing by 0.5 m² (half a square metre) per additional bedroom.
Stairs count as 1 m²,Any space with head height lower than 900 mm does not count,And space between the height of 900 mm and 1.2 m counts as 50%.
For a wheelchair-adaptable dwelling, we need to consider the provision of a lift between the circulation spaces on each storey.
The liftway should measure at least 1.1 m by 1.65 m internally,With ideally a circulation space in front of it of at least a 1.5 m turning circle.
This space can be used in the meantime for another purpose,but, as with wheelchair storage, it needs to be easily converted without major structural work.
In a wheelchair-accessible dwelling, the lift needs to be installed,and the 1.2 m circulation space in front of the lift is mandatory.
In a two-storey dwelling, a lift to BS 5900 or a lift platform to BS EN 81-41 may be sufficient.
When it comes to private stairs and changes of level within the dwelling,it should be good enough for the ambulant disabled person to move up and down, assisted by a stair lift when needed.
Generally, stairs should follow the requirements of Part K,but a minimum of 850 mm width, measured at 450 mm above the pitch line of the stairs, is required.
Stair lift charging sockets should be provided at top and bottom.
There should be no steps between spaces at any given level.
Now, habitable rooms—living areas—To be usable, need to have a convenient transfer between the principal private entrance, the water closet, and the living space.
The principal living area must be located within the entrance storey.
We need to ensure that the minimum combined internal floor area of living, dining, and kitchen space is:
Between 25 m² and 37 m² for between 2 and 8 bed spaces,
Increasing by 2 m² per additional bed space.
Glazing to a principal window should start at a maximum of 850 mm above floor level.
In kitchen and eating areas,we again consider whether the dwelling is wheelchair-adaptable or wheelchair-accessible.
In the adaptable case, the dwelling must be capable of being relatively easily changed into a wheelchair-accessible layout.In the accessible case, it must already meet those accessibility requirements.
The kitchen and eating areas should be in one room, or directly connected,and there should be sufficient space to manoeuvre a wheelchair:
1.5 m wide approach to kitchen units and appliances,
And the same clearance between opposite units.
The length of the worktops varies:
For adaptable dwellings, the required starting length is 4330 mm (about 4.3 m),
Extending up to 6730 mm for 6 to 8 bed spaces.
The document provides a handy diagram with more detailed explanation.
When the kitchen becomes accessible, we must ensure that the person has access to a cooking, food washing, and food preparation area that is adjustable in height,and that they will not suffer injury while using it.
That section of the worktop should be at least 2.2 m long,with clear space underneath for the wheelchair user,and the sink should be thermally insulated to protect the person's legs from scalding.
The sink should not be deeper than 150 mm.Taps should be easy to operate with levers.
We also ought to consider space to place items when taking them out of appliances.The document requires at least 400 mm of worktop space for that purpose.
Drainage and water supply should be adaptable and flexible, with isolated valves.
Typically, the worktop level should be adjustable between 700 mm and 950 mm above floor level.
In bedrooms, there is also a handy diagram for principal bedrooms shown in the document.
It gives the required access space:
1 m between the sides and front of the bed,
Up to 600 mm depth for bedside tables,
1.2 m × 1.2 m manoeuvring square at the door entrance and corners of beds.
One bedroom should be located close to the accessible bathroom,but all bedrooms should be accessible.
The baseline requirement is to provide a 750 mm wide access route between the door and the window.
The principal bedroom should be no further than a single storey away from the entrance storey and be a minimum of 13.5 m² and 3 m wide, clear of obstructions.
Similarly, every other double or twin bedroom may be 1 m² smaller,and the single bedroom can go down to 8.5 m², being at least 2.5 m wide.
Ceilings should be strong enough to accommodate a 200 kg capacity hoist.All but principal bedrooms can have 1 m access to one side of the bed.
The dimensions for furnishings should follow those from Appendix D of this document.
Sanitary facilities considerations will be similar again.We need to cater to disabled people, and the building will need to be ready for adaptation or fully accessible from the start.
We will face dimensional requirements for bathrooms:
The minimum number of bathrooms per number of bedrooms,
And that bathrooms with level-access showers are designed as wet rooms.
Ducts, walls, and boxing to every water closet, bath, and shower will need to be strong enough to accommodate grab rails, seats, and other adaptations.
The required strength is again 150 kg per m².Similarly, ceilings will need to be capable of holding a 200 kg hoist.
The level of the water closet pan should be a minimum of 400 mm in height.
Basins and sinks should be wall-hung at 775 mm to 850 mm above the finished floor level,with clear zone underneath to allow wheelchair access.
We should avoid stacks and soil pipes within the bathroom, but if unavoidable, they should be located next to the water closet.
Regarding the number of water closets or cloakrooms:
We start at the default of one bathroom with level access shower for up to three bed spaces.
Then add a separate water closet at four bed spaces,
And a walk-in shower and a bath at five bed spaces.
For single-storey dwellings, a single bed space is considered a room between 8.5 m² and 12.5 m².Two- or three-storey dwellings will follow suit.
Water closet facilities on the entrance storey:It is important to have an appropriate water closet on the entrance storey.
In that vein, it needs to be large enough and designed as a wet room with a level access shower.The wet room and water closet may, however, be accommodated by two separate rooms.
The door to the water closet should open outwards.
There are very handy diagrams showing the minimum requirements for both adaptable and accessible toilets.
We must always keep in mind that if we do an adaptable water closet,it needs to be easily transformable into an accessible one,with bathroom facilities arranged to allow for that change.
These can be arranged in different ways,and depending on whether the room is adaptable or accessible,the layout requirements will be slightly different.Again, diagrams are shown in the document that depict distances and arrangements for us.
Dwellings up to four bed spaces should have a minimum of one bathroom that contains:
A water closet,
A basin, and
An installed level-access shower,
with the option for later installation of a bath, unless that is already provided elsewhere in the dwelling.
However, the level-access shower/bathroom should be on the same level as the principal double bedroom.
In essence, we need to ensure that people can wash and bathe safelyand that there is sufficient access to facilities in line with the number of bed spaces—meaning people who may require access to the facilities simultaneously are given the opportunity to do so.
Services and controls should be conveniently placed.
That means:
Consumer units should be installed between 1350 mm and 1450 mm above floor level.
Switches, sockets, stopcocks, and controls should be between 700 mm and 1000 mm in height,
And at least 300 mm away from internal corners.
(This does not include radiator controls, obviously.)
Kitchen appliances need isolator switches located within a similar height range.
The handle to at least one window in the principal living area should also be at a similar height,and the remaining windows should be between 450 mm and 1200 mm—though these can be controlled remotely as an alternative.
Door handles, locks, latches, and catches should be both easy to grip and operate,and installed at a height of 850 mm to 1000 mm.
Light switches should have individual plates,unless they are wide rocker or full-plate fitting type.
Switches to double sockets should be positioned externally (surface mounted, not recessed).
We should also provide a door entry phone with remote door release facility, located in the main living space and the principal bedroom.
Also, the bedroom should be prepared for the installation of bedhead controls.A telephone and a power socket should be positioned together in the main living space.
Taps and bathroom controls should be suitable for one-hand operation by a person with a limited grip.Boiler controls should occupy space between 900 mm and 1200 mm,and radiator controls between 450 mm and 1 m.
Now, private outdoor space:Every outdoor space should accommodate a turning circle of 1.5 m, free of any door swings.
Paths should be at least 1500 mm wide,terminated again with that 1.5 m turning circle.
Gates and doors should be at least 850 mm wide, with 300 mm and 200 mm functional nips on both sides—similar to other provisions.
And of course, the paving should be of suitable surface and not too steep.
[Music]
So, this is it folks—Approved Document M: Access to and Use of Buildings, Volume One – Dwellings.
Let’s sum it up section by section:
Section 0 – Introduction
This section introduces the document scope, which applies to new dwellings and material alterations, but excludes extensions.
The document outlines access and usability requirements for dwellings categorized into three levels:
Visitable dwellings (M4(1)),
Accessible and adaptable dwellings (M4(2)), and
Wheelchair user dwellings (M4(3)).
It’s important to check for any optional requirements attached to planning permission.Building regulations must be followed alongside the Equality Act and other relevant codes.
In the case of conflict, Part M takes precedence over Part K.
Section 1 – Category 1: Visitable Dwellings
These dwellings ensure reasonable access for disabled individuals who can walk, to and within the dwelling.
A toilet must be accessible on the entry or principal storey, if there is a habitable room at that level.Access to the bathroom must be step-free, and switches or outlets must be reachable for people with limited reach.
This section ensures basic usability for visitors with mobility impairments.
Section 1A – Approach to the DwellingThe approach must provide safe and convenient access, be at least 900 mm wide, unobstructed, and non-slip.If ramps are necessary, they must meet gradient and length requirements, and include an alternative stepped route.
Communal entrances must be wheelchair accessible, with a minimum width of 775 mm.Communal lifts must accommodate wheelchairs with appropriate landings, doors, and controls.
Section 1B – Private Entrances and SpacesPrivate entrances should be level where possible and allow wheelchair access.Internal doorways must be wide enough—750 mm to 800 mm—to allow circulation.Corridors must enable easy movement, and steps should be avoided where feasible.
Water closet facilities must provide sufficient clearance, with outward-opening doors.Electrical fixtures should be installed at accessible heights.
Section 2 – Category 2: Accessible and Adaptable Dwellings
These dwellings accommodate occupants with diverse needs, including older or disabled people, and be adaptable over time.
Designs should allow for future modifications, such as the addition of grab rails or stair lifts, without major works.These provisions apply where specified in planning approval.
Section 2A – Approach to the DwellingExternal approaches must provide step-free, accessible paths,similar to Category 1, but with added flexibility for future adaptation.
Ramps, entrances, and circulation routes should support future changes,ensuring long-term usability as occupant needs evolve.
Section 2B – Private Entrances and Internal SpacesSpaces must be designed to allow straightforward adaptation.Door widths, circulation areas, and bathrooms should be flexible to accommodate aids and adaptations.
The goal: ensure easy future modification, promoting long-term accessibility and usability.
Section 3 – Category 3: Wheelchair User Dwellings
Dwellings in this category must either be adaptable for wheelchair users or fully wheelchair-accessible from the outset.
This includes access to and usability of all facilities within the dwelling.If specified in planning, Category 3 overrides Category 2.
Section 3A – Approach to the DwellingApproach routes must ensure step-free access from parking and external areas.All approaches must be fully accessible, with safe, compliant ramps, stairs, and lifts.
Section 3B – Private Entrances and Internal SpacesPrivate entrances must provide level access for wheelchairs.Doorways, circulation spaces, and rooms must support full wheelchair maneuverability.
Bathrooms and kitchens must be adaptable or preconfigured,with appropriate heights for controls, fixtures, and appliances.The design ensures that wheelchair users can fully inhabit the dwelling without additional modifications.
In the next episode, we will move to Approved Document M: Access to and Use of Buildings, Volume Two – Buildings Other Than Dwellings.
I hope you enjoyed this episode,and that the considerations of Approved Document M: Access to and Use of Buildings – Volume One: Dwellings are now clear to you.
If you have any questions, reach out to me on LinkedIn or send me an email.I am more than happy to help you out.
At Bytnar Limited, we deal with planning, designing, and managing your projects,and we’re always glad to facilitate a free initial consultation to steer you in the right direction.
Visit www.bytnar.co.uk and get in touch,whether your question is “Can you help with my project?” or “What should I do?”—we’ll provide a piece of non-obligatory advice.
At Bytnar, we help our clients design and execute their dream homes or investments.If your building is falling apart, we can also help investigate the reasons and provide you with an appropriate strategy, design, and specifications for repair.
Thank you again for listening.Please voice your opinions,and I’m waiting for you on LinkedIn—I want to hear from you.
See you next week!Bytnar Designs the World Around You.
Toodloo! 👋
Piotr Bytnar BEng (Hons) MSc CEng MIStructE
Chartered Structural Engineer who deals with the Architecture of buildings. His Master's Studies led him to an in-depth understanding of risk and contract arrangements in construction as well as specialist knowledge in soil mechanics.
He and his team help homeowners and property developers to design and deliver construction projects reducing waste in time and the cost. He believes that the construction project is an iterative process that can be well managed and it is best managed if all the aspects of the project definition and management are dealt with in-house or coordinated by one organisation. His team works to all stages of RIBA and ISTRUCTE stages of work and enables contractors to deliver projects on-site providing risk evaluations, methodologies for execution of works and temporary works designs.
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