Accessible parking bays: sizes, numbers and where they go
Accessible parking standards come from BS 8300, the local plan, building regulations and the Equality Act at once. Here is how the four fit together on a planning layout.
The accessible parking planning requirement almost never comes from one document. Dimensions come from BS 8300, provision rates come from the adopted local plan or a parking standards supplementary planning document, the marking comes from traffic signs regulations, and the duty that sits behind all of it comes from the Equality Act 2010. Get any one of them wrong on the layout and you will be redrawing the car park after the highway officer's consultation response, which is the worst moment to discover that four bays have to move.
Blue badge bays also sit at the awkward junction of planning and building control. Planning fixes the number and the position. Building regulations fix what happens once the car park serves a building.
Where the standards come from
Four sources, in the order they will be quoted at you.
The local plan or parking standards SPD sets the number. This is the document the case officer applies, and it is usually expressed as a percentage of total spaces or a fixed minimum per use. Read it alongside the general parking standards, because accessible bays are normally counted within the total rather than added to it.
BS 8300-2:2018 sets the geometry for buildings and their approaches, with BS 8300-1:2018 covering the external environment. These are the figures a highway officer will cite for bay size, access zones and gradients. Check the current edition before you dimension anything, since the standard was substantially revised from the older BS 8300:2009.
Approved Document M under the Building Regulations 2010 governs what the completed building must provide, in Volume 1 for dwellings and Volume 2 for other buildings. Planning permission does not discharge it.
And the Equality Act 2010 sits underneath. Section 149 puts a public sector equality duty on the council when it decides your application, and on larger or more sensitive schemes an Equalities Impact Assessment is the document that shows the duty has been considered properly.
Bay dimensions and access zones
A designated off-street bay to BS 8300-2 is 2.4 metres wide by 4.8 metres long, with a 1.2 metre access zone along each side and a further 1.2 metre zone at the rear where a vehicle may be loaded from behind.
Those zones are the part that gets designed out. A bay drawn at 2.4 metres against a wall with a kerb behind it meets the bay dimension and fails the standard, because a wheelchair user cannot get out of the car. Where two bays sit side by side, the side access zone can be shared, which is how the familiar pair of bays with a single hatched strip between them arises.
The rear zone matters for rear-loading vehicles and for anyone transferring at the back of an estate car. Where bays back onto a footway, that footway can sometimes serve as the zone provided it is level and unobstructed, but a raised kerb defeats it.
| Element | Dimension to design to |
|---|---|
| Bay | 2.4 m wide by 4.8 m long |
| Side access zone | 1.2 m, shareable between adjacent bays |
| Rear access zone | 1.2 m where rear loading is possible |
| Marked bay symbol | Wheelchair symbol to the traffic signs regulations |
On-street bays follow different dimensions again, so if the scheme relies on a bay in the carriageway, get the highway authority's own detail rather than adapting the off-street one.
Surfacing, gradients and the route to the door
The bay is only useful if the route from it works. Surfaces need to be firm, level and slip-resistant in wet weather. Loose gravel, cobbles and wide-jointed setts are all common in residential schemes and all fail in practice, whatever the landscape drawings say about character.
Keep the bay and its access zones as flat as the drainage allows. Cross falls should be gentle, and a bay set on a slope to suit levels elsewhere will be a problem for the life of the building.
The route to the accessible entrance needs a dropped kerb or, better, a flush transition, and it should not cross a service yard or a delivery route. Distance matters too. Put designated bays as close to the accessible entrance as the layout allows, and treat anything beyond a short level walk as a design failure to be justified rather than a decision to be defended.
How many bays
For housing schemes in London, the London Plan 2021 Policy T6.1 requires that a proportion of dwellings have an accessible on-site parking space from the outset, with the ability to increase provision on request as residents' needs change. Outside London, the number comes from the local plan or the parking standards SPD, and the variation between authorities is wide.
For commercial, retail, leisure and employment uses, most councils apply either a percentage of total capacity or a minimum number, taking the rates in BS 8300-2 as the starting point and adjusting for local circumstances. Take the number from the adopted document rather than the standard, then check the standard to see whether the adopted number looks thin for the use in question.
Where the local standard is silent or the use is unusual, evidence the need. A Parking Survey using a recognised methodology gives you a defensible base for a scheme that departs from the standard, and it is far more persuasive than an assertion about demand. The wider question of how maximum and minimum standards interact deserves its own look, because parking standards in the local plan frame everything else in this section.
Wheelchair user dwellings and their parking
Dwellings built to the M4(3) wheelchair user standard need parking designed for the occupant, not for a visitor. Approved Document M Volume 1 expects a space that can be widened to 3.3 metres, which is a standard 2.4 metre bay plus a 0.9 metre access zone. The widening does not have to exist on day one, and it does have to be possible without rebuilding a wall or losing the adjacent space.
Show the widened dimension on the layout as a dashed extent. Officers reviewing an accessible housing policy will look for it, and it costs nothing at design stage while being close to impossible to retrofit once the neighbouring plot is built out.
Where an M4(3) dwelling has a driveway rather than a bay in a communal court, check the gradient from the parking area to the entrance and the covered approach. A step-free route that only works in dry weather is not a step-free route.
Designing so bays can be added later
The provision that matters over 30 years is the provision you can change. Two moves make that possible.
First, group designated bays where the surrounding geometry has slack: next to a hatched area, a landscape strip that can be paved, or a bay run that can lose one space to widen two. Second, avoid putting the accessible bays in the tightest corner of the car park, which is exactly where a scheme squeezed for numbers tends to put them.
Electric vehicle charging adds a live constraint. A charge point installed in the middle of a bay run, with a bollard and a cable route, can make later conversion impossible. PAS 1899:2022 covers accessible charging specifically and is the document to design against where charge points and designated bays coincide.
Showing it on the drawings
Case officers are not going to scale your drawing. Make the compliance visible.
- Dimension at least one accessible bay and its access zones on the layout, with the shared zone arrangement shown where bays are paired.
- Add a schedule to the drawing giving total spaces, designated spaces and the percentage.
- Mark the accessible route from each bay to the entrance, and show the level or dropped kerb transitions.
- Show the widened extent for any M4(3) dwelling parking.
- Note surfacing materials for the bays and the access route, and confirm they are firm and slip-resistant.
- Reference the standard you have designed to and the policy the number comes from.
Carry the same numbers into the written evidence. A Design and Access Statement that states the provision and the standard, and a Transport Statement that reconciles it with the total parking count, closes off the two questions the highway officer would otherwise ask.
This is general guidance, not legal advice. Accessible design standards and local parking policies change, so check the current standard and the adopted policy with your local planning authority or a qualified professional before relying on it.
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Frequently asked questions
What size should a blue badge parking bay be?
BS 8300-2:2018 sets a designated off-street bay at 2.4 metres wide by 4.8 metres long, with a 1.2 metre access zone to each side and a further 1.2 metre zone to the rear where rear loading is possible. Adjacent bays can share a side zone. On-street bays follow separate dimensions set by the highway authority.
How many accessible bays does a development need?
The number comes from the adopted local plan or parking standards supplementary planning document rather than from a national rule. Most authorities express it as a percentage of total capacity or a minimum per use, taking BS 8300-2 as a starting point. In London the London Plan sets residential requirements directly.
Do accessible bays count towards the total parking number?
Usually yes. Most standards count designated bays within the overall provision rather than in addition to it, which matters where a maximum standard applies and the scheme is at the cap. Read the wording of the adopted standard carefully, because a small number of authorities treat them as additional.
Can gravel or setts be used for an accessible bay?
Not sensibly. Surfaces for designated bays and the route to the entrance need to be firm, level and slip-resistant when wet. Loose gravel, cobbles and wide-jointed setts defeat wheels and walking aids. Where a scheme wants that character elsewhere, keep the bays and the accessible route in a bound surface and vary materials away from them.
What parking does an M4(3) wheelchair user dwelling need?
Approved Document M Volume 1 expects a space capable of being widened to 3.3 metres, being a standard bay plus a 0.9 metre access zone. The widening need not exist from the start, so long as it can be achieved later without rebuilding walls or losing the neighbouring space. Show the widened extent on the layout.
Sources and further reading
This article is general guidance about the planning system in England and, where stated, the rest of the UK. It is not legal or professional advice. Check your local planning authority’s validation requirements and take professional advice for your specific site.