The requirement
Spain doesn’t set one ramp number — it sets two, and which one applies to your job depends on where the ramp is and what it connects. Both live in the same Documento Básico, DB-SUA, but in different sections.
DB-SUA 1 — the general ramp. For a ramp that isn’t part of an accessible itinerary — an internal change of level, a minor structural ramp, most of what happens inside or around an ordinary house — the slope is capped at 12% (§4.3.1.1). Any path sloped over 4% counts as a “rampa” under the CTE’s own definition. A general ramp also needs:
- Landing at the top and bottom of a same-direction run: at least as wide as the ramp, and 1.50 m long on the line of travel (§4.3.2.3, §4.3.3). A direction-change landing must not reduce the ramp’s width.
- Max flight length 15 m (§4.3.2.1).
- Handrail 90–110 cm, required once the ramp rises more than 550 mm at a slope of 6% or steeper (§4.3.4).
DB-SUA 9 — the accessible itinerary. This is a stricter, separate branch, and here’s the scoping detail that actually decides which one you’re building to: DB-SUA §1.1.1 states that accessibility conditions do not apply inside the private limits of a single-family dwelling — except that the exterior itinerary from the dwelling to the public road must still meet them, unless the dwelling itself is exempted from that requirement. In practice, that usually means the front-door approach path on an ordinary house — not anything inside it — is where the accessible-itinerary figures bite:
| Flight length | Max gradient |
|---|---|
| Under 3 m | 10% |
| Under 6 m | 8% |
| 6 m or longer | 6% |
(§4.3.1.1(a).) An accessible-itinerary ramp also needs:
- Cross-fall (pendiente transversal) 2% max (§4.3.1.2).
- Clear width at least 1.20 m (§4.3.2.3).
- Max flight length 9 m (§4.3.2.1).
- Continuous handrails on both sides, plus a 10 cm minimum kerb on any open edge, once the ramp rises more than 18.5 cm at 6% or steeper — with a second, lower handrail at 65–75 cm (§4.3.4).
Which one applies? If you’re building the approach to the front door of an ordinary single dwelling house, that exterior route generally has to hit the DB-SUA 9 length-banded figures. A general or minor ramp elsewhere on the job — inside the house, into a shed, a change of level in the garden — is checked against the flatter 12% DB-SUA 1 figure instead. Don’t assume the two give the same answer for the same rise; they’re different tests for different parts of the site.
Vehicle ramps are a third, separate case: a car-park ramp that also carries pedestrians, and isn’t part of an accessible itinerary, is capped at 16% (§4.3.1.1(b)) and carries no fixed flight-length limit.
Headroom for any ramp uses the same rule as a stair — 2.10 m minimum in restricted-use zones, 2.20 m elsewhere — set in DB-SUA 2 §1.1, not a ramp-specific figure.
Work it out on site
You’re building the accessible-itinerary approach to a new dwelling’s front door. The threshold sits 450 mm above the path. How long does the ramp need to be?
- Try the shallowest band first. The 6% band applies once the flight is 6 m or longer, and has no upper length limit of its own — but check the steeper bands first, since they’re only allowed for a shorter flight. At 10% (allowed only under 3 m), 450 mm needs 450 ÷ 0.10 = 4500 mm (4.5 m) of run — that’s over the 3 m limit for the 10% band, so 10% isn’t allowed here.
- Try 8% (allowed only under 6 m). 450 ÷ 0.08 = 5625 mm (5.625 m) — under the 6 m limit for that band. This works, and it’s the shallowest available option that still fits its own length cap.
- Add the landing. At least 1.50 m long, at the top.
So: about 5.6 m of ramp at 8%, with a 1.50 m landing. The slope calculator does this rise-over-run and band check for you.
Do it in 5 seconds
Related
- Part of the Spanish Building Regulations hub — the hub, with the DBs that set the rules.
- Building the stairs that ramp might replace? See Spanish stair & barrier rules.
Sources
- CTE DB-SUA — Seguridad de Utilización y Accesibilidad, §4.3.1.1 (general ramp gradient, accessible-itinerary bands, vehicle ramps), §4.3.1.2 (cross-fall), §4.3.2.1 (flight length), §4.3.2.3 / §4.3.3 (landings and width), §4.3.4 (handrails), and §1.1.1 (accessibility conditions not mandatory inside the private limits of a single-family dwelling, except the exterior itinerary to the public road). Read it at codigotecnico.org.
Read this first. These figures are from the current DB-SUA articulado (Real Decreto 450/2022, de 14 de junio, corrected BOE 02/02/2023). A further partial revision of the CTE affecting DB-SUA was in public consultation at the time these figures were checked, not yet adopted — always confirm the current DB-SUA text at codigotecnico.org before you build to it.
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