CBC 11A and 11B Units on the Enlarged Plans

Where this guide picks up

Whether a building falls under California Building Code Chapter 11A, 11B or both is covered in the 11A and 11B guide. This guide picks up after that decision, on the enlarged unit plans, where the clearances have to be drawn and dimensioned for a plan checker to verify. The figures come from the 2025 California Building Code, in effect since January 1, 2026.

Chapter 11A organizes the requirements inside covered dwelling units in its Division IV: Section 1130A (accessible route within the unit), 1131A (changes in level), 1132A (doors), 1133A (kitchens), 1134A (bathing and toilet facilities), 1135A (laundry rooms) and 1136A (electrical receptacle, switch and control heights) (2025 CBC Chapter 11A, UpCodes).

Doors in an 11A unit

Requirement	2025 CBC	Value
Net clear opening, interior and secondary exterior swinging doors	1132A.3	32 inches with the door open 90 degrees
Level floor or landing on the unit side of the primary entry door	1132A.5.1	44 inches long minimum
Level area on both sides of interior doors	1132A.5.1	42 inches long minimum, measured at right angles to the door (39 inches where the door gives 34 inches clear)
Strike-side clearance on the side the door swings toward	1132A.5.2	level area extends 18 inches past the strike edge
Door hardware	1132A.8	centered 30 to 44 inches above the floor

Source: 2025 CBC 1132A, gocodebook.

On the plan, the 18-inch strike-side clearance is the one that moves walls. A bedroom door set tight to a corner, or a closet door with its strike tight to a return, fails it. The cure is to draw the clearance zone on the enlarged plan as a dashed rectangle at every door, so the reviewer sees it and so does the team drawing the casework.

Kitchens in an 11A unit

Requirement	2025 CBC	Value
Clear floor space at the sink, dishwasher, refrigerator and oven	1133A.2	30 by 48 inches, parallel or forward approach
Clear floor space at the range or cooktop	1133A.2	30 by 48 inches, parallel approach
Clear width, U-shaped kitchen with a range or cooktop at the base, parallel approach	1133A.2.1	60 inches minimum
Clear width, U-shaped kitchen with knee and toe space at the base for a forward approach	1133A.2.1	48 inches minimum
Clear width, all other kitchens	1133A.2.1	48 inches minimum
Countertop	1133A.4	a 30-inch minimum length of countertop at the sink and a separate 30-inch work surface
Knee and toe space, where provided	1133A.7	30 inches wide minimum, centered on the element

Source: 2025 CBC 1133A, gocodebook.

The 48-inch clear width is the California figure, and it governs a California set. On a galley kitchen, the dimension is measured between the faces of opposing cabinets, countertops, appliances or walls, so a refrigerator that projects past the base cabinets sets the width.

Bathrooms in an 11A unit

Which bathrooms comply

Section 1134A.2 gives two options: either all bathrooms in the unit comply fully, or one bathroom complies fully and the others meet a reduced set of requirements. The unit plan needs to say which option it uses, since the choice changes what every other bathroom must show.

Clearances and reinforcement

Requirement	2025 CBC	Value
Maneuvering space where the door swings into the room	1134A.4	30 by 48 inches within the room, outside the door swing
Water closet clear floor space	1134A.7.1	48 inches wide, extending 36 inches in front of the fixture
Water closet centerline	1134A.7.1	17 to 18 inches from the grab bar wall
Lavatory clear floor space	1134A.8.2	30 by 48 inches, centered on the fixture
Bathtub clear floor space	1134A.5.1	48 inches parallel by 30 inches perpendicular, at the side
Shower clear floor space	1134A.6.3	30 inches wide by 48 inches long, outside the shower, parallel to the control wall
Grab bar reinforcement at the tub, toilet and shower	1134A.5.2, 1134A.6.4, 1134A.7.2	in the walls, 32 to 38 inches above the floor

Source: 2025 CBC 1134A, gocodebook.

Reinforcement is easy to lose because it is invisible once the wall is closed. The enlarged plan or the interior elevation should show the reinforcement zone at each fixture, dimensioned to the floor, and the wall type or a detail should say what the reinforcement is.

Switches and outlets

Section 1136A sets the reach range for electrical receptacles, switches and controls in covered units: receptacle outlets on branch circuits of 30 amperes or less, and communication receptacles, sit no higher than 48 inches to the top of the box and no lower than 15 inches to the bottom of the box, measured from the finished floor (UpCodes, 1136A). On the set this lands on the interior elevations and in the electrical notes; the unit plan only needs to point to them.

11B mobility units

Where a project is public housing under Chapter 11B, some units have mobility features and are drawn to a stricter standard. The 11A and 11B guide covers how many. On the enlarged plan, three things change:

An accessible route through the unit. Section 11B-809.2 requires accessible routes complying with Division 4 within the unit, so turning spaces, clear widths and door clearances follow the 11B Division 4 figures.
The kitchen. Section 11B-809.3 puts the kitchen on the accessible route and points it to the 11B kitchen requirements.
One bathroom with every fixture. Section 11B-809.4 requires the fixtures that comply with Sections 11B-603 through 11B-610 to sit in the same bathroom, so a resident does not travel between rooms to reach them (UpCodes, 2025 CBC Chapter 11B).

Units with adaptable features under 11B, and units with communication features for residents with hearing or vision impairments, add their own items. Each unit type needs its own enlarged plan, labeled with its features in the unit matrix.

Laundry and changes in level

Two smaller sections round out Division IV. Section 1135A covers laundry rooms and laundry equipment inside covered units, and Section 1131A covers changes in level along the accessible route within the unit, which on a multifamily building most often means the threshold at a balcony or patio door and the step down to a shower. Both belong on the enlarged plan from the day the unit is laid out: a stacked washer and dryer in a closet that leaves no clear floor space in front of it, or a balcony door with a tall sill set by the waterproofing detail, are the kinds of conflicts a plan checker catches and a field crew cannot fix without changing the drawings.

Mirrored and flipped unit types

Most multifamily buildings repeat a handful of unit types, and most of those types appear in mirrored versions. A mirrored unit is a different plan for accessibility purposes: the door swings, the strike sides and the grab bar walls all flip. A set that draws one enlarged plan per type and labels the mirror "similar, opposite hand" leaves the plan checker to confirm the clearances in a plan nobody drew. Drawing each mirrored type, or at least each mirrored bathroom and kitchen, closes that gap. In Revit, a mirrored type is a separate view of the same unit group, so the cost is a sheet, and the benefit is a plan check comment avoided on every floor.

How it shows on the set

A California multifamily set handles unit accessibility in three places that must agree:

The unit matrix on the general sheets: every unit by type and floor, with its 11A, 11B mobility, 11B adaptable or communication designation.
The accessibility plans: the accessible routes through the building and to each designated unit.
The enlarged unit plans: each unit type with clearances drawn and dimensioned, fixture centerlines, reinforcement zones and the door clearance at every door.

The usual corrections come from the three disagreeing: a unit moved on the floor plan and not in the matrix, an enlarged plan drawn once for a type that has a mirrored version with a different door swing, or a clearance shown in the plan and lost when the casework was drawn.

Where the studio fits

TECTO Studio draws enlarged unit plans in your Revit model with the 11A and 11B clearances drawn and dimensioned at every door and fixture, and keeps the unit matrix in step with the plans. The construction documents page describes the work.

Accessible and adaptable units on a California multifamily set