Access to and Use of Buildings - Complete Guide
Approved Document M Requirements for Dwellings & Non-Dwellings
Building Regulations Part M ensures that buildings in England are accessible and usable for everyone, including people with disabilities. Updated in 2026, Approved Document M sets standards for wheelchair access, ramps, doorways, toilets, parking, and circulation spaces to create inclusive environments.
Part M is divided into two volumes: Volume 1 covers dwellings (houses and flats) with categories M4(1), M4(2), and M4(3). Volume 2 covers buildings other than dwellings such as shops, offices, schools, and public buildings. Compliance is mandatory for all new builds, extensions, and material changes of use in England as of 2026.
Part M requirements ensure reasonable provision is made for people to gain access to, use, and move through buildings and their facilities. The regulations cover approach routes, entrance doorways, horizontal and vertical circulation, accessible facilities, and wayfinding aids.
Applies to: Houses, flats, apartments, residential buildings
Categories: M4(1), M4(2), M4(3)
Effective from: 1 March 2016, updated 2026
Covers: Approach routes, parking, entrances, circulation, facilities
Applies to: Shops, offices, schools, hotels, public buildings
Sections: M1, M2, M3
Effective from: 1 October 2015, updated 2026
Covers: Access, extensions, sanitary conveniences, facilities
New buildings: All new construction must comply
Extensions: Some requirements apply
Material alterations: Upgraded access required
Change of use: Must meet Part M standards
Developers: All new housing developments
Self-builders: New dwellings and extensions
Commercial builders: Shops, offices, public buildings
Local authorities: Planning and Building Control enforcement
Volume 1 introduces three categories of accessible dwellings. All new homes must meet at least M4(1) standards. Local planning authorities may require M4(2) or M4(3) where justified by local housing needs assessments.
✓ M4(1) Mandatory Requirements (All New Homes):
📐 M4(2) Enhanced Requirements (When Required by Planning):
♿ M4(3) Full Wheelchair Accessibility (Specialized Housing):
Part M specifies precise dimensions for doorways, corridors, rooms, and facilities to ensure wheelchair accessibility and comfortable movement for all users.
| Element | M4(1) Visitable | M4(2) Accessible | M4(3) Wheelchair |
|---|---|---|---|
| Main Entrance Door | 775mm clear opening | 850mm clear opening | 850mm clear opening |
| Internal Doors | 750mm clear opening | 775mm clear opening | 850mm clear opening |
| Corridor Width | Not specified | 900mm minimum | 1200mm minimum |
| Hallway Width | 750mm minimum | 900mm minimum | 1200mm minimum |
| Turning Space | Not specified | 1500mm diameter | 1500mm diameter |
Where level access is not achievable, ramped access must be provided with specific gradients and dimensions. Part M integrates with Approved Document K for ramp safety requirements.
| Aspect | Requirement | Details |
|---|---|---|
| Maximum Gradient | 1:20 (5%) | Preferred for wheelchair users, least effort |
| Steeper Gradient | 1:15 (6.7%) | Acceptable for short distances (max 10m) |
| Maximum Gradient | 1:12 (8.3%) | Only for very short distances (max 5m), with handrails |
| Ramp Width | 1500mm minimum | 1800mm preferred for passing |
| Landing Length | 1500mm minimum | At top, bottom, and intermediate landings |
| Landing Frequency | Every 10m max | More frequent on steep gradients |
| Handrails | Both sides | 900-1000mm height, 40-45mm diameter |
| Edge Protection | 100mm upstand | Prevents wheelchair wheels slipping off edge |
Volume 2 applies to buildings other than dwellings including shops, offices, educational buildings, hotels, restaurants, healthcare facilities, and public buildings. Requirements ensure inclusive access for employees, visitors, and service users.
Gradient: Maximum 1:20, steeper only if unavoidable
Width: 1800mm minimum (1500mm absolute minimum)
Surface: Firm, even, slip-resistant, no loose gravel
Dropped kerbs: 1:12 max gradient, flush with road
Effective width: 800mm minimum clear opening
Threshold: Level or max 15mm upstand
Vision panels: 500-1500mm from floor level
Door pressure: Max 30N opening force, closers regulated
Clear space: 1500mm diameter turning circle
Seating: Mix of chair types with/without armrests
Counter height: 760mm max, or dual-height provision
Induction loops: Hearing enhancement systems required
Corridor width: 1200mm minimum (1800mm two-way)
Door opening: 800mm effective clear width minimum
Passing places: 1800×1800mm every 10m in narrow corridors
Level changes: Ramped or lifted, no single steps
Part M mandates provision of accessible sanitary facilities with specific layouts, dimensions, and fittings. Requirements differ between dwellings and non-dwellings, with detailed specifications for wheelchair users.
| Compartment Type | Minimum Size | Layout | Facilities Required |
|---|---|---|---|
| Wheelchair WC (Unisex) | 2000mm × 1500mm | Side or lateral transfer to WC | WC, washbasin, grab rails, alarm, coat hook |
| Peninsular WC | 2200mm × 1500mm | Centrally positioned WC | Transfer from both sides, additional space |
| Ambulant Disabled WC | 800mm wide minimum | Standard cubicle with grab rails | Horizontal and vertical grab rails, outward door |
| Accessible Bathroom | 2400mm × 2400mm | WC, shower, washbasin | Level-access shower, seat, rails, 1500mm turning |
| Changing Places | 3000mm × 4000mm min | Large facility with hoist | Ceiling hoist, height-adjustable bed, space for carers |
Accessible parking must be provided close to accessible entrances with appropriate dimensions and level surfaces. Blue Badge parking spaces are designated for disabled drivers and passengers.
🚗 Accessible Parking Standards 2026:
Multi-storey buildings require accessible vertical circulation via passenger lifts complying with BS EN 81-70 (accessible lifts). Stairs must also be accessible for ambulant disabled people.
Minimum size: 1100mm wide × 1400mm deep car
Door width: 800mm clear opening minimum
Controls: 900-1100mm height, tactile, audio feedback
Visual/audio: Floor indicators inside and outside car
Application: Low-rise (max 2m) level changes
Platform size: 1100×1400mm minimum
Speed: Max 0.15 m/s vertical travel
Controls: Constant pressure or automatic with safety edges
Rise: 150-170mm maximum per step
Going: 250mm minimum tread depth
Width: 1000mm minimum between handrails
Handrails: Both sides, 900-1000mm height, continuous
Fire-fighting lifts: Must accommodate stretcher (1100×2100mm)
Refuge areas: Required on each storey for assisted escape
Communication: Two-way emergency voice communication
Signage: Clear emergency evacuation instructions
When an existing building undergoes material change of use (e.g., warehouse to restaurant, house to office), Part M requirements apply to the relevant parts of the building to ensure accessibility.
⚠️ Change of Use Triggers Part M Compliance:
Developers and designers frequently encounter challenges meeting Part M standards. Understanding common issues helps ensure compliance and avoid costly redesigns.
Issue: Builders creating 20-25mm step at external doors
Requirement: Maximum 15mm upstand at any external threshold
Solution: Weather bars, drainage channels, careful detailing
Issue: Measuring frame width rather than clear opening
Requirement: Clear width when door open 90°, minus door thickness and stops
Solution: Use wider door sets (926mm for 850mm clear)
Issue: Electricians installing at habitual heights
Requirement: Sockets 450-1200mm, switches 750-1200mm
Solution: Clear site instructions, pre-fit inspections
Issue: Fittings blocking transfer space or turning circle
Requirement: Precise positioning per AD M diagrams
Solution: Use CAD templates, verify on-site before fixing
Compliance with Part M adds costs to construction projects, though often marginal when designed-in from project inception. Retrofitting accessibility is significantly more expensive than inclusive design from the start.
| Category Upgrade | Typical Cost Increase | Main Cost Drivers |
|---|---|---|
| M4(1) Standard Compliance | £500-1,500 per dwelling | Wider doors, level thresholds, socket heights |
| M4(1) to M4(2) Upgrade | £5,000-9,000 per dwelling | Wider doors, larger circulation, future adaptability |
| M4(1) to M4(3) Upgrade | £15,000-25,000 per dwelling | Lifts, enlarged rooms, accessible facilities, structural |
| Commercial Building (Volume 2) | 2-5% total build cost | Accessible WCs, lifts, ramps, wider circulation |
| Accessible WC (Non-Dwelling) | £4,000-7,000 per facility | Larger space, grab rails, alarm, specialized fittings |
| Passenger Lift Installation | £25,000-45,000 | Lift car, shaft, controls, building works |
| External Ramp (1:20 gradient) | £1,500-3,500 per metre rise | Foundations, surface, handrails, landings, drainage |
M4(1) does not apply to dwelling extensions. However, extensions to non-dwellings (Volume 2) must comply with Part M sections M2 and M3, ensuring accessible routes and sanitary facilities where provided. If an extension creates a new main entrance, that entrance must meet Part M standards.
M4(2) creates accessible and adaptable homes suitable for most people, including those with reduced mobility. M4(3) provides full wheelchair accessibility with larger spaces, step-free access throughout, lifts in multi-storey homes, and accessible facilities. M4(3) is specified for wheelchair users from occupation, while M4(2) allows future adaptation.
Yes, Building Control can approve departures from Part M where compliance is not technically feasible or would be unreasonably onerous given site constraints, topography, or existing building configuration. Applications must demonstrate that reasonable provisions for access have been made within practical constraints. Document submitted reasoning carefully.
For non-dwellings, minimum 5% of total parking capacity must be accessible (at least one bay even if total < 20 spaces). Spaces must be 3300mm wide with 1200mm hatched transfer zone, located within 50m of accessible entrance. For M4(2) dwellings, parking bays (if provided on plot) must be 3300mm wide.
Maximum 15mm upstand at external door thresholds for M4(1), M4(2), and M4(3) dwellings, and for non-dwelling accessible entrances. Any upstand must be chamfered or rounded. Internally and for M4(3), level thresholds (0mm) are required throughout. Use weather bars and drainage rather than raised thresholds for weather protection.
For M4(1) and M4(2), no lift is required in two-storey houses. Provide accessible WC at entrance level. For M4(3) wheelchair user dwellings, a lift or step-free arrangement (e.g., split-level, single-storey) is mandatory to access all habitable rooms, bedroom, and bathroom. Lift platform size must be 1100×1400mm minimum.
M4(1): 775mm main entrance, 750mm internal doors. M4(2): 850mm main entrance, 775mm internal doors. M4(3): 850mm all doors. Clear opening is measured when door is open 90°, excluding door thickness, frame, and stops. A 926mm door set typically provides 850mm clear opening. Non-dwellings require 800mm minimum effective clear width.
Part M does not require existing buildings to be upgraded unless there is a material change of use, material alteration, or extension (for non-dwellings). When triggered, reasonable provision must be made for accessibility appropriate to the building use and practical constraints. Listed buildings may have special considerations requiring negotiation with Conservation Officer and Building Control.