UK ramp calculator, Approved Document M
Enter the rise and the gradient and this returns the going, the surface length, the longest flight allowed, how many flights and landings you need, and the minimum width. It asks whether the building is a dwelling first, because Approved Document M gives two different answers and most published guidance only gives one of them.
Volume 1 and Volume 2 are different documents
This is the thing to get right before any number matters. Approved Document M comes in two volumes. Volume 1 covers dwellings. Volume 2 covers buildings other than dwellings. They do not agree on ramps, and almost every UK ramp page publishes the Volume 2 figures without saying which building they apply to.
| Volume 1, dwellings | Volume 2, other buildings | |
|---|---|---|
| Gradient and flight length | 1:15 or shallower, up to 10m. 1:12, up to 5m. | 1:20 up to 10m. 1:15 up to 5m. 1:12 up to 2m. |
| Minimum width | 900mm | 1500mm |
| Handrails | Not required | Both sides |
| Maximum rise per flight | Set by the flight length | 500mm |
M4(1), M4(2) and M4(3)
Volume 1 contains three optional standards for new dwellings and only one of them applies by default.
- M4(1) Visitable dwellings. The baseline. It applies to new dwellings automatically.
- M4(2) Accessible and adaptable dwellings. Applies only where a planning condition imposes it.
- M4(3) Wheelchair user dwellings. Also only through a planning condition.
M4(2) and M4(3) are not things you opt into and not things that apply because a building sounds like it should be accessible. They are triggered by the planning permission for the site. Check the decision notice before designing to either, and check it before assuming neither applies.
Landings, and why a long ramp gets expensive fast
A ramp is not one continuous slope. Each flight is capped, and between flights you need a level landing. Under Volume 2 that is 1500mm of level surface for an intermediate landing and 1200mm at the top and the bottom, and none of it counts toward the going.
This is why ramps take so much more room than people expect. A 900mm rise at 1:12 is 10.8 metres of slope before landings. Under Volume 2 that gradient caps a flight at 2 metres, so you need six flights and five intermediate landings, and the real footprint is well over 18 metres. Run the same rise at 1:20 and it is 18 metres of slope in two flights. The shallower ramp is shorter overall, which is the opposite of what most people assume.
A ramp is not always the answer
Under Volume 2, a total rise over 2 metres means a ramp on its own is not enough and a lift or another means of access has to be provided as well. On a constrained site it is worth testing that number early, because it can change the whole approach rather than just the ramp.
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Start free with Built SimpleFrequently Asked Questions
What is the maximum ramp gradient under UK building regulations? 1:12, and only for a short flight. Approved Document M Volume 2 allows 1:12 for up to 2 metres, 1:15 for up to 5 metres and 1:20 for up to 10 metres. Volume 1, which covers dwellings, allows 1:12 up to 5 metres and 1:15 up to 10 metres.
How wide does a wheelchair ramp have to be in the UK? 1500mm of surface width under Volume 2 for buildings other than dwellings. Volume 1 requires 900mm for a ramp serving a dwelling.
Do I need handrails on a ramp at a house? Approved Document M Volume 1 does not require a handrail on a ramp serving a dwelling. Volume 2 requires handrails on both sides. A handrail is worth fitting on a domestic ramp regardless of whether the regulation asks for it.
How long can a ramp be before it needs a landing? It depends on the gradient and the volume. Under Volume 2 a 1:12 flight caps at 2 metres, 1:15 at 5 metres and 1:20 at 10 metres. Intermediate landings are 1500mm long and do not count toward the going.
Does M4(2) apply to my house? Only if a planning condition imposes it. M4(1) is the standard that applies to new dwellings by default. M4(2) and M4(3) are optional standards that come through planning, so check the decision notice.
Related calculators and guides
Sources
- Approved Document M, Volume 1, Dwellings, 2015 edition incorporating 2016 amendments, HM Government.
- Approved Document M, Volume 2, Buildings other than dwellings, 2015 edition incorporating 2020 and 2024 amendments, HM Government.
- Building Regulations 2010, Schedule 1, Part M. Approved Documents are free under the Open Government Licence.
