Building accessibility: DB-SUA 9 requirements

Everything revolves around the accessible route (itinerario accesible): the path a person with reduced mobility, in particular a wheelchair user, can travel autonomously and safely. The section requires accessible routes connecting the main entrance with the building's relevant zones, and the document's terminology annex precisely defines their geometric and functional conditions.

The essential conditions, in reference values, form a repertoire worth memorising: clear passage widths of around 1.20 metres in corridors with defined occasional narrowings, doors with a minimum clear width of 0.80 metres and obstacle-free turning spaces on both sides, limited slopes, around 4 percent on horizontal routes and under the specific regime of accessible ramps beyond that, floors without upstands and controls usable at regulation height. Level changes are overcome with an accessible ramp or an accessible lift: stairs are never part of an accessible route.

Accessible ramps have their own defined geometry: maximum slopes decreasing with flight length, around 10 percent for very short flights, 8 for medium ones and 6 for the longest admissible flights, with landings of sufficient size, handrails at two heights and lateral protection. They are great consumers of floor area: overcoming one metre of level difference requires in practice more than twelve metres of ramp plus landings, and that arithmetic explains why the ramp improvised after the fact almost never fits.

The accessible lift completes the vertical repertoire: a car with minimum regulatory dimensions depending on door configuration, around 1.00 by 1.25 metres in the usual configurations of an ordinary building, automatic doors, stopping precision and usable control panels. In most multi-family and commercial buildings, the accessible lift is simply the lift: designing it accessible from the start costs almost nothing, adapting it later costs a new shaft.

On top of the routes sit the accessible provisions, modulated by the building's use and size. The general picture, in its main lines:

Requirements on pools, reserved places in auditoriums or accessible accommodation in public residential use complete the picture in their respective uses. The logic is always the same: provision grows with scale and with the public character of the building.

Section SUA 9 is the state-level floor of accessibility, not its ceiling. The autonomous communities have their own accessibility regulation, and numerous municipalities add ordinances. The design rule, already stated in the general DB-SUA article, is to apply at each point the most restrictive condition and record in the report which regulation governs each decision.

The crossover has a practical dimension worth anticipating: regional and municipal technical services review their own regulation first, and the typical mismatches appear in the details, toilet dimensions, dwelling reserves, parking space conditions. A comparative table of CTE versus regional regulation, prepared at project kick-off for the specific territory, is a short deliverable that saves entire correction cycles.

The CTE reform going through approval also adds novelties in this area, among them new adapted toilet requirements for people with ostomies, a sign of the general direction of regulatory evolution: more provision, not less. It is worth verifying the text in force at the time of endorsement.

Section SUA 9 does not live in isolation: it shares geometry with the evacuation requirements of the DB-SI. Accessible routes and escape routes run along the same corridors and doors, and the code articulates both worlds with refuge areas, protected spaces next to the cores where people who cannot use the stairs await assistance. The coordination is detailed in the article on occupant evacuation; the golden rule for the design is to size corridors, doors and cores once, with both tables on the table, because the element that meets one regulation and fails the other is rebuilt whole.

The section's cost splits into three different natures, and separating them orders any estimate. All three are budgeted separately and in different units.

The first is floor area: routes, turning circles, landings and ramps consume square metres that in development are sellable metres. It is the dominant cost and the most invisible in the construction budget, because it appears not as an item but as lost efficiency. It is managed at sketch stage, not in the quantities.

The second is equipment: the differential of the accessible lift where there is one, the technical aids of adapted toilets, bars, fixtures and specific taps, the accessible controls and signage. This is the visible cost, and as an indicative order of magnitude the whole of accessibility sits between 2 and 5 percent of the PEM (presupuesto de ejecución material, the direct construction cost) in ordinary multi-family buildings, with the lift as the dominant item, following the reading method of the article on the cost of CTE compliance.

The third is the cost of late adaptation: the building that did not reserve the geometry pays for accessibility at refurbishment prices, with forced ramps, lifts in impossible shafts and rebuilt toilets. The asymmetry between designing accessible and adapting afterwards is among the largest in the whole code.

The first is treating accessibility as a final design layer: routes condition cores, widths and slopes from the first scheme, and adding them late triggers chain redesigns. Routes are drawn at the same time as the plan.

The second is complying with the CTE while ignoring the regional regulation, or the reverse: only the more restrictive of the two protects the project. Both texts are compared requirement by requirement.

The third is the broken chain: a building with a perfect adapted toilet that cannot be reached in a wheelchair complies with nothing; the route is verified complete, from the street to the last accessible element. Verification follows the complete route rather than element by element.

The fourth is forgetting the less visible provisions, linked parking spaces, controls, signage, attention points, which are precisely the ones inspections check with a list in hand. The list of provisions is worth walking through before the quantities are closed.

The fifth is not measuring the technical aids: bars, seats and equipment of adapted toilets form a specific item that quantities produced from generic drawings regularly omit. The item is defined from the actual adapted toilet rather than a generic drawing.