UK Ramp Gradients (Approved Document M)

The requirement

In England the ramp into a new home is set by Approved Document M (Access to and use of buildings), backed up by Approved Document K for ramps that are part of the building. For a normal new house the baseline you must meet is Category 1 — M4(1), the “visitable dwelling” rule. Here are the numbers.

The steepest slope allowed is 1:12 — 1 unit up for every 12 along. But how far you can run before a landing depends on the slope:

Always pick the gentlest slope you can actually fit. 1:15 is easier to walk and lets you run twice as far before a break.

One more line worth knowing from Approved Document K: a surface at 1:20 or steeper should be designed as a ramp. Flatter than that and it counts as a level path, with no ramp landing rules.

Landings

The flat bit at each end and between flights is the landing. On a home approach:

• there must be a landing at the top and bottom of the ramp,
• plus one between flights and at any change of direction, and
• every landing must be at least 1200 mm long, clear of any door or gate swing.

Width

Every ramp flight on a private home approach needs a minimum clear width of 900 mm.

The optional higher standards

M4(2) (accessible and adaptable) and M4(3) (wheelchair user) are optional — they only apply where the local planning authority makes them a condition. If your job is one of these, the ramp is gentler: M4(2) is between 1:20 and 1:12 and M4(3) is between 1:20 and 1:15, and both cap the rise at 500 mm per flight. Check which one, if any, your planning permission calls for.

Work it out on site

You’re building the step-free way into a house. The threshold sits 400 mm above the finished path. How long is the ramp?

1. Pick the slope. Go for the gentler 1:15 if you have room — it’s easier to walk. 1:15 means 1 up for every 15 along.
2. Do the sum. 400 mm up × 15 = 6000 mm, so 6 m of ramp run. (That 6 m is just the maths of this example, not a code figure.)
3. Check the run limit. At 1:15 a single flight can run up to 10 m, and 6 m is well under that — so one flight works, no mid-ramp landing needed for length.
4. Add the landings. A landing at least 1200 mm long goes at the top and the bottom, clear of the door swing.

If you were forced onto the steeper 1:12 instead: 400 × 12 = 4800 mm, so 4.8 m — still under the 5 m limit for 1:12, so a single flight would just scrape in. The slope calculator does this rise-over-run sum for you.

Do it in 5 seconds

Related

• Part of the UK building rules for chippies — the hub, with the England, Wales, Scotland and Northern Ireland split.
• Building the stairs that ramp might replace? See UK stair rules — rise, going and guarding.

Sources

• Approved Document M (Access to and use of buildings), Volume 1: Dwellings, 2015 edition incorporating 2016 amendments — para 1.7 — the M4(1) home approach ramp: 1:12 steepest (max 5 m flight), 1:15 gentler (max 10 m flight), 900 mm minimum width, and 1200 mm landings. Optional M4(2)/M4(3) at paras 2.10 and 3.10. Confirm at gov.uk.
• Approved Document K (Protection from falling, collision and impact), 2013 edition — Section 2, paras 2.3 & 2.8, Diagrams 2.1–2.2 — ramps that are part of the building: 1:12 max slope and the “1:20 or steeper = design it as a ramp” line. Confirm at gov.uk.
• Adoption / edition caveat: These are the England figures. Approved Documents are statutory guidance, not the law itself — the legal duty is to meet Part M and Requirement K1 of Schedule 1 to the Building Regulations 2010, and other approaches are allowed if they meet the requirement. M4(1) is the mandatory baseline for a new-build dwelling; M4(2) and M4(3) apply only where a local planning authority imposes them. Wales publishes its own Approved Documents (values can differ), and Scotland (Building Standards Technical Handbooks) and Northern Ireland (Technical Booklets) are separate regimes not covered here. Always confirm the current document for the nation your job is in.