Here are the numbers: under CBC 11B-502, the primary van accessible parking stall is 12 feet wide (144") with a 5-foot access aisle. Exception configuration: 9 feet wide (108") with an 8-foot access aisle. Either way, the total footprint is 17 feet. You need at least 98 inches (8'-2") of vertical clearance at the stall, aisle, and the entire route to the exit. Surface slope is 2% max in any direction. Signage requires both an ISA sign and a separate "Van Accessible" sign, bottom of sign at least 60 inches above grade. That's the short version. Keep reading for where projects actually fail.

Van Accessible vs. Standard Accessible: What's the Difference?

A standard accessible stall is 9 feet wide with a 5-foot access aisle. That works for most wheelchair users transferring from a car door. It doesn't work for wheelchair van users who deploy a ramp or lift from the side — which typically requires 8 feet of clear, flat, unobstructed space adjacent to the vehicle.

That's why CBC 11B-502.3.3 requires the wider aisle: the 8 feet accommodates a van side ramp deployed at full extension. The exception 9-foot stall width with wider 8-foot aisle works because the extra width gets absorbed into the stall itself rather than a separate aisle — useful when you're tightening a parking module and can't swing an 8-foot aisle striped separately.

The two configurations are equivalent for compliance. Use whichever fits your parking geometry better.

How Many Van Accessible Stalls Do You Need?

CBC 11B-208.2.4 requires at least one van accessible stall for every 6 total accessible stalls (or fraction of six). So if your accessible count is 1 through 8, you need one van accessible. If it's 9 through 16, you need two. And so on.

The van accessible stall has to be within the accessible group it's serving — it can't be in a remote corner of the lot. It also has to be on the shortest accessible route to the accessible building entrance (CBC 11B-208.3.1). "Closest available" is the standard. If you have a choice between a front-row van stall that routes pedestrians across a drive aisle versus a slightly farther stall with a direct sidewalk connection, the one with the shorter accessible route wins — not the one closest by vehicle travel distance.

The Vertical Clearance Rule: Where Covered Parking Gets Complicated

CBC 11B-502.5 requires 98 inches (8'-2") of vertical clearance at the van accessible stall and access aisle, and on the vehicular route connecting those spaces to an exit. This isn't just overhead clearance at the stall itself. It includes:

That last bullet is the one that creates headaches in structured parking. A lot of garages are designed with 7'-2" typical clearance and a single designated van clearance path. If your van accessible stall is on Level 2 and the structural beams drop to 7'-0" along the path to the exit ramp, you have a violation — even if the stall itself has 9 feet of clearance.

On covered surface lots with timber canopies or photovoltaic carport structures, verify clearance at every structural member along the full path. Carport columns and beam haunches are the most common offenders in our site planning reviews.

Surface Slope: 2% in Any Direction, No Exceptions

CBC 11B-502.4 limits slope within the stall and access aisle to 2% maximum in any direction. Same standard as the accessible route, same enforcement headaches.

Parking lots drain. They have to. Most asphalt and concrete lots are designed at 1.5% to 5% to get water to the catch basins. When you put an accessible stall in a lot that drains across the stall at 3%, your stall cross-slope is 3% and you're in violation.

The fix: grade the accessible stalls explicitly. Don't just show "2% typical" on the drainage plan and assume it works out. Show spot elevations at the four corners of each accessible stall and at the corners of the access aisle. Demonstrate in the plan check submittal that the slope in every direction stays at or below 2%. Plan checkers who know what they're doing will look for this. The ones who don't will find it during construction inspection.

A diagonal resultant slope above 2% is also a violation. If your stall drains at 1.5% in the drive aisle direction and 1.5% perpendicular, your diagonal resultant is about 2.12%. That's a fail. Do the math during design, not after the concrete is poured.

Signage: Two Signs, Not One

Standard accessible stalls get one ISA sign. Van accessible stalls require two under CBC 11B-502.6:

  1. The ISA (International Symbol of Accessibility) sign on a post or wall
  2. A separate "Van Accessible" sign mounted directly below it

Bottom of sign height: 60 inches minimum above the finished surface of the parking stall. The ISA sign and Van Accessible sign are typically mounted on the same post, with Van Accessible directly below the ISA. Sign faces toward the front of the stall (the side from which a driver approaching can read it).

Don't just specify one sign with "Van Accessible" text added below the ISA symbol on a single panel. The code requires a separate sign element for "Van Accessible." Most sign vendors sell a two-sign stack as a standard product — use it.

Pavement markings are also required: blue paint with the ISA logo painted on the stall surface. Check local jurisdiction standards for specific ISA logo sizing — some cities have standard plan details that specify dimensions.

Access Aisle Location: The Most Common Plan Check Failure

The access aisle has to be on the passenger side of the van for a side-ramp deployment. That means, for most configurations, the access aisle is between two stalls — shared between a van accessible stall and the adjacent accessible stall. One 8-foot aisle serves both.

Where it fails: the designer puts the van stall at the end of a row with the access aisle on the driver's side (the wall side), or puts the access aisle on the wrong side relative to a fixed obstruction. A van ramp deploying into a concrete wall or a landscape planter doesn't work.

The other failure mode: the access aisle is the right width on the plan, slopes transversely — meaning the low side of the aisle is against the curb or planter, and water (and ramp foot traffic) runs toward the obstruction. Keep the aisle draining away from any obstruction that a ramp user would need to navigate.

End-of-Row vs. Shared Aisle Configurations

When a van accessible stall is at the end of a parking row, the access aisle is at the open end — no adjacent stall required. This is often the cleanest configuration because there's no vehicle crowding the aisle from the other side and pedestrian clearance to the accessible route is easier to establish.

In shared-aisle configurations (van stall + accessible stall sharing the 8-foot aisle), both stalls share access to the same aisle and both stalls must connect to the accessible route at the aisle end. Make sure your site plan shows that connection explicitly — a direct path from the access aisle to the accessible route without crossing a drive lane, or with a marked crosswalk and curb ramp if a drive aisle crossing is unavoidable.

Putting It Together in a Plan Check Submittal

When we're producing accessible parking documentation for a plan check submittal, we include:

If the plan checker has to guess at any of these, they'll write a correction. We'd rather front-load the documentation and get through first-round review clean. It's faster for everyone.

If you're working through an accessible parking layout on a current project — especially one with covered parking, tight module constraints, or a sloped site — our site planning team has done this a lot. The geometry usually has a solution. We also carry it through construction if you need construction administration support to verify the field grades before the concrete sets.

Give us a call and we'll walk through it.

Reco Prianto, PE is the principal civil engineer at Calichi Design Group. He has designed accessible parking facilities for K-12 schools, multifamily developments, and commercial projects across California under DSA and local jurisdiction review.