IBC Accessibility Requirements: Chapter 11, ADA and A117.1

TL;DR — IBC Chapter 11 Accessibility

• IBC Chapter 11 sets scoping — what must be accessible, where, and how many. ICC A117.1 sets the technical dimensions — how to make each element accessible. The ADA runs parallel and typically yields the same result; where they differ, the more restrictive applies.

• The baseline rule is total accessibility: IBC §1103.1 requires every site, building, facility, and space to be accessible unless a specific exception in §1104–§1112 applies. Exemptions are narrow.

• Accessible route must connect parking, accessible building entrance, and all accessible spaces within the building. Where a building has multiple floors, an accessible route between floors is required unless a specific story exception applies (IBC §1104.4).

• Accessible parking: 1 in 25 spaces up to 100 total, scaling per IBC Table 1106.2. 1-in-6 accessible spaces must be van-accessible. Outpatient medical facilities: minimum 10% accessible. Rehab/therapy: minimum 20%.

• Accessible means of egress (IBC §1009): required in multi-story buildings. Areas of refuge required at each accessible floor above/below exit discharge unless the building is fully sprinklered with NFPA 13.

• Accessible toilet rooms: at least one toilet room on each accessible route must be accessible. Type A and Type B dwelling units (R-2 buildings) have specific plumbing fixture clearance requirements under ICC A117.1.

IBC Chapter 11 and the Three-Document Framework

Accessibility in buildings is governed by three overlapping instruments that designers must coordinate simultaneously:

IBC Chapter 11 — the scoping document. It answers: what must be accessible, where it must be accessible, and how many accessible elements are required. Chapter 11 does not specify dimensions — it tells you which elements trigger the requirement.

ICC A117.1 (Accessible and Usable Buildings and Facilities) — the technical standard referenced by the IBC. It answers: how to make each element accessible. Door clearances, ramp slopes, toilet room layouts, reach ranges, grab bar locations — all of these are in A117.1, not in Chapter 11.

ADA Standards for Accessible Design (2010) — the federal civil rights law enforced by the Department of Justice. The ADA runs parallel to, and is largely harmonized with, the IBC/A117.1 framework. Buildings that comply with IBC Chapter 11 and ICC A117.1 are generally deemed to comply with the ADA's design requirements. The ADA goes further in some areas — particularly in existing buildings undergoing renovation, where the barrier removal obligation exists independent of whether construction is triggered.

The practical workflow: Chapter 11 identifies an element as requiring accessibility → A117.1 provides the exact dimensions → the ADA is reviewed for any additional or more stringent requirements that apply to the specific occupancy.

The Default Rule: Everything Is Accessible

IBC §1103.1 states the fundamental principle of Chapter 11 plainly: sites, buildings, structures, facilities, elements, and spaces — temporary or permanent — shall be accessible to individuals with disabilities.

This is an opt-out framework, not an opt-in framework. Everything is required to be accessible by default. Sections 1104 through 1112 then establish specific, enumerated exceptions. If a building element or space isn't listed in an exception, accessibility is required.

Key general exceptions in IBC §1103:

Detached one- and two-family dwellings and their accessory structures are exempt from Chapter 11 entirely. These buildings are governed by the IRC.

Employee work areas have a reduced scope: they must allow persons with disabilities to approach, enter, and exit the work area, but the interior of the work area itself is not required to be fully accessible. The exception does not apply to accessible means of egress (§1009) or accessible alarms within the work area (§907.5.2.3.1).

Raised areas in certain occupancies — courtroom raised platforms, loading docks, raised work platforms — are exempt when the change in elevation is essential to the function of the space.

Walk-in coolers and freezers intended for employee use only are exempt.

Everything else — every public space, every common use area, every customer-facing element — is accessible unless a specific exception applies.

Accessible Route — IBC §1104

The accessible route is the physical thread that connects all required accessible elements: it runs from the site arrival point (parking, public transportation stops, public sidewalk) through the accessible building entrance and to every accessible space and element within the building.

IBC §1104.1 requires at least one accessible route within the site to connect accessible parking, accessible passenger loading zones, public streets and sidewalks, and the accessible building entrance.

IBC §1104.2 requires at least one accessible route from the accessible building entrance to public spaces and employee work areas on the same floor.

Connecting floors: IBC §1104.4 requires an accessible route between stories when a building has multiple floors accessible to the public or employees. The accessible route between floors is typically provided by elevator, ramp, or platform lift. Exceptions apply in specific conditions:

• Stories and mezzanines with an aggregate area not exceeding 3,000 square feet that are above or below the accessible level, where the occupancy is not Group A, B, M, or R-1 (IBC §1104.4, Exception 1)

• Stories with a total area not more than 3,000 square feet in Group A, B, M when conditions are met (§1104.4, Exception 2)

• Specific Group R-2 residential configurations where Type A or Accessible units are on accessible floors (§1104.4, Exception 4)

The story exception is narrower than many designers assume — 3,000 square feet of aggregate area is a small floor plate, and most multi-story commercial buildings do not qualify for any floor exemption.

Accessible route width: Per ICC A117.1 §403.5, the minimum clear width of an accessible route is 36 inches, except at passing spaces where 60 inches is required, and at doorways where the clear opening width governs.

Accessible route slope: Maximum running slope is 1:20 (5%) without triggering ramp requirements. Steeper running slopes — up to 1:12 (8.33%) — require a compliant ramp with handrails, edge protection, level landings, and surface requirements per ICC A117.1 §405.

Accessible Building Entrance — IBC §1105

At least 60 percent of all public entrances must be accessible (IBC §1105.1). This does not mean 60 percent of all doors — it means 60 percent of the entrance points the public uses to enter the building. A secondary service entrance does not count toward the public entrance total.

Where a building has a single public entrance, that entrance must be accessible. Where a tenant space has a single primary public entrance, it must be accessible.

Accessible entrances must be on an accessible route from the public way, from accessible parking, and from accessible passenger loading zones.

Door requirements at accessible entrances (ICC A117.1 §404):

• Minimum clear width: 32 inches (measured from face of door to stop at 90 degrees open)

• Maneuvering clearances: specific clearances on the latch side depend on whether the door is pull-side or push-side and whether it has a closer

• Threshold: maximum 1/2 inch vertical change; beveled at 1:2 maximum slope for changes between 1/4 and 1/2 inch

• Hardware: operable with a closed fist — lever handles, loop pulls, push bars compliant; round knobs not compliant

Accessible Parking — IBC §1106

Where parking is provided on a site, accessible parking spaces must be provided in quantities calculated per IBC Table 1106.2. The calculation applies separately to each parking facility on the site — a surface lot and an adjacent parking garage are counted independently.

IBC Table 1106.2 — Required Accessible Parking Spaces

Total Parking Provided	Minimum Accessible Spaces
1–25	1
26–50	2
51–75	3
76–100	4
101–150	5
151–200	6
201–300	7
301–400	8
401–500	9
501–1,000	2% of total
Over 1,000	20 + 1 for each 100 over 1,000

Source: IBC 2024 Table 1106.2. Calculate each parking facility separately.

Special Requirements by Occupancy

Hospital outpatient facilities (IBC §1106.4): At least 10% of care recipient and visitor parking must be accessible — higher than the general table.

Rehabilitation facilities and outpatient physical therapy facilities (IBC §1106.5): At least 20% of patient and visitor parking must be accessible. These facilities serve persons with mobility impairments who require proximate parking for access.

Residential occupancies (IBC §1106.3): Group I-1 and R-1: follow Table 1106.2. Group R-2 and R-3 where Accessible, Type A, or Type B units are required: 2% of each type of parking space, not less than one.

Van-Accessible Spaces

For every six accessible parking spaces — or fraction of six — at least one must be van-accessible (IBC §1106.6). Van-accessible spaces require:

• 11-foot minimum width with a 5-foot access aisle, OR

• 8-foot minimum width with an 8-foot access aisle (per ICC A117.1)

• 98-inch minimum vertical clearance on the access aisle and along the vehicular route to the space

Van-accessible spaces must be identified with a "Van Accessible" sign mounted below the standard International Symbol of Accessibility (ISA).

Location of Accessible Parking

Accessible parking spaces must be located on the shortest accessible route from parking to the accessible building entrance (IBC §1106.7). Where parking is provided within or beneath a building, accessible spaces must be provided within or beneath the building — not in an adjacent surface lot.

Accessible Means of Egress — IBC §1009

Accessible means of egress is technically in Chapter 10 (Means of Egress) rather than Chapter 11, but it is the egress component of the accessibility system and must be coordinated with Chapter 11's accessible route requirements.

IBC §1009.1 requires accessible means of egress in every building where accessibility is required. At least one accessible means of egress must serve each accessible story — two are required where the accessible means of egress is a stairway or ramp.

Areas of Refuge — IBC §1009.6

An area of refuge is a space in the path of egress where persons who are unable to use stairways can shelter temporarily and communicate with building emergency staff. Areas of refuge are required adjacent to each required accessible means of egress at floors above or below the level of exit discharge.

Areas of refuge must:

• Be accessed from the accessible means of egress with minimal travel

• Contain at least one wheelchair space of 30 x 48 inches for every 200 occupants on that floor (at least two wheelchair spaces)

• Have a 2-way communication system with the building's main entry or fire command center

• Be posted with instructions for emergency use

Areas of refuge are NOT required when:

• The building is equipped throughout with an NFPA 13 automatic sprinkler system (IBC §1009.3, Exception 1) — the most important exception

• The story is at the level of exit discharge

• Horizontal exits provide refuge capacity for all occupants

• Accessible means of egress uses a supervised automatic elevator per §1009.4

The NFPA 13 sprinkler exception eliminates the area of refuge requirement in fully sprinklered buildings. In practice, most new commercial buildings required to be fully sprinklered also eliminate the area of refuge requirement — but the designer must confirm the sprinkler standard. NFPA 13R (residential systems) and NFPA 13D (one- and two-family dwellings) do not substitute for NFPA 13 for this exception.

Elevators as Accessible Means of Egress

In buildings four or more stories above grade, at least one elevator must be provided as part of the accessible means of egress (IBC §1009.4). This elevator must be accessed from an area of refuge (unless the building is fully sprinklered) and must have standby power to operate in the event of normal power loss.

Accessible Toilet Rooms — IBC §1109

Where toilet rooms are provided, each toilet room must be accessible (IBC §1109.2). This means every toilet room that is required to serve a public or employee area must comply with ICC A117.1 toilet room requirements — not just one toilet room per floor, and not just one room per building.

The exceptions are narrow:

• Single-occupant toilet rooms accessed only through a private office are not required to be accessible, provided the office is not required to be accessible (§1109.2, Exception 2)

• Toilet rooms that are part of a clustered toilet room layout where an accessible toilet room is provided nearby may qualify for a limited exception

ICC A117.1 toilet room requirements (technical dimensions that flow from the IBC's scoping):

• 60-inch turning radius or T-turn space within the room

• Water closet: centerline 17–19 inches from the side wall; seat height 17–19 inches above finish floor; rear wall grab bar 36 inches minimum, side wall grab bar 42 inches minimum

• Lavatory: 34-inch maximum rim height; knee and toe clearance below for forward approach; insulated pipes

• Accessible route from the door to the water closet and lavatory without obstruction to maneuvering clearances

• Door hardware: operable without tight grasping or twisting

Accessible Dwelling Units — IBC §1107

Group R-2 multi-family buildings must provide accessible dwelling units in quantities based on the total number of units. IBC Chapter 11 establishes three tiers of accessible dwelling units:

Accessible Units — fully accessible dwelling units meeting ICC A117.1 §1002 technical requirements. Required in specific Group I and R-1 occupancies.

Type A Units (ICC A117.1 §1003) — high-accessibility dwelling units, broadly comparable to ADA Fair Housing Act requirements. Maneuvering clearances, accessible plumbing fixtures and hardware, accessible routes between all habitable rooms. Required in 2% of units in Group R-2 buildings of four or more stories with elevator service (IBC §1107.6.2).

Type B Units (ICC A117.1 §1004) — dwelling units meeting the Fair Housing Act Accessibility Guidelines for Type B accessible units. Designed for visitability and basic access. Required in all ground-floor Group R-2 units not required to be Type A, when the building has elevator service (IBC §1107.6.1.1).

The Type A/Type B distinction is one of the most project-specific and frequently misapplied requirements in Chapter 11. The thresholds depend on building height, elevator service, unit count, and whether the project is new construction or a renovation.

For the complete framework on Fair Housing Act compliance and its overlap with IBC Chapter 11, see: ADA accessibility requirements

Assembly Seating — IBC §1108

Where fixed seating is provided in assembly occupancies, accessible wheelchair spaces must be dispersed throughout the seating area. IBC §1108.2 requires:

• Wheelchair spaces on an accessible route

• 1% of fixed seating — minimum one wheelchair space — must be accessible

• Wheelchair spaces distributed among various seating areas to provide viewing angles comparable to those available to the general public

• Companion seats adjacent to each wheelchair space

Wheelchair spaces must comply with ICC A117.1 §802 for size, forward and side approach, and floor surface.

IBC Chapter 11 vs. ADA: What Designers Need to Know

The IBC governs the permit process. Building officials enforce IBC Chapter 11 and ICC A117.1. Compliance is required to receive a certificate of occupancy.

The ADA governs civil rights liability. The Department of Justice and private plaintiffs enforce Title III of the ADA. Compliance is required regardless of whether construction occurred, for public accommodations.

Overlap and differences:

• The 2010 ADA Standards and ICC A117.1 have been extensively harmonized. In most respects, a building that complies with IBC/A117.1 also complies with ADA design standards.

• Scoping differs. The ADA does not use the IBC's three-tier dwelling unit classification (Accessible/Type A/Type B). The IBC does not incorporate the ADA's removal of barriers obligation for existing buildings.

• Technical differences exist. Grab bar requirements, parking signage, toilet paper dispenser placement, and a few other elements differ between A117.1 and the 2010 ADA Standards. Where differences exist, most jurisdictions advise designing to the more stringent of the two.

• Jurisdictional amendments add complexity. California's CBC Chapter 11B is substantially more stringent than either the IBC or ADA in many areas. New York, Texas, and other states also have accessibility amendments that exceed the IBC baseline.

The practical takeaway: compliance with IBC Chapter 11 and ICC A117.1 is necessary but not sufficient for ADA compliance in all cases. Designers should treat the IBC as the floor for building code compliance and confirm ADA requirements independently for public accommodations and commercial facilities.

Common Plan Review Failures in IBC Chapter 11

1. Accessible route not continuous. The accessible route from parking to entrance must be continuous with a compliant surface, slope, and width. A break in pavement, a curb without a curb cut, or a ramp without compliant landings interrupts the accessible route and fails plan review.

2. Too few accessible parking spaces. Calculations per Table 1106.2 are per parking facility, not per site. Designers who combine counts from separate lots undercount accessible spaces.

3. Missing van-accessible space. One in six accessible spaces must be van-accessible. Projects with only one or two accessible spaces often omit the van-accessible designation.

4. Area of refuge missing where required. In buildings without full NFPA 13 sprinklers, areas of refuge are required at each accessible floor. Non-sprinklered buildings with elevator access are frequently submitted without areas of refuge.

5. Accessible toilet room not provided on every floor. Where toilet rooms exist on each floor, each toilet room must be accessible. A single accessible toilet room on the ground floor does not satisfy the requirement for upper floor toilet rooms.

Research Accessibility Requirements for Your Project with Melt Code

Accessibility compliance requires coordinating IBC Chapter 11, ICC A117.1, the 2010 ADA Standards, and any state or local amendments — simultaneously. A California project adds CBC Chapter 11B requirements. A federally funded project adds additional Section 504 obligations. A multifamily housing project adds the Fair Housing Act.

Melt Code searches across all of these documents and your state's adopted code to answer specific questions like "How many Type A units are required in a 150-unit R-2 apartment building in Illinois with elevator service?" or "Is an area of refuge required in a three-story NFPA 13R sprinklered building?"

→ Get accessibility answers on Melt Code: https://www.meltplan.com/code

Frequently Asked Questions

What is the difference between IBC Chapter 11 and the ADA?

IBC Chapter 11 is a building code requirement enforced during the permitting process — it sets scoping for accessibility in new construction and substantial renovation. The ADA is a federal civil rights law enforced by the DOJ and through private litigation — it applies to public accommodations and commercial facilities regardless of whether construction occurred. The two are largely harmonized through the 2010 ADA Standards and ICC A117.1, but they differ in scope, enforcement mechanism, and some technical requirements. IBC compliance is the threshold for certificate of occupancy; ADA compliance is an ongoing obligation for business operations.

What is ICC A117.1 and how does it relate to IBC Chapter 11?

ICC A117.1 (Accessible and Usable Buildings and Facilities) is the technical standard referenced by IBC Chapter 11 for accessibility dimensions and specifications. Chapter 11 is the scoping document — it tells you what must be accessible. A117.1 is the technical document — it tells you how to make each element accessible, with specific dimensions for clearances, slopes, reach ranges, fixtures, and hardware. The two are designed to work together: IBC Chapter 11 triggers the requirement, then you go to A117.1 for the dimensional details.

How many accessible parking spaces are required under IBC?

The number is calculated per IBC Table 1106.2 based on the total number of parking spaces in each parking facility. Starting thresholds: 1 accessible space for 1–25 total spaces, 2 for 26–50, and scaling upward. Hospital outpatient facilities require at least 10% accessible. Rehabilitation and physical therapy facilities require at least 20% accessible. For every six accessible spaces, at least one must be van-accessible. Each separate parking facility on a site is calculated independently.

When is an area of refuge required under IBC?

An area of refuge is required at each accessible floor above or below the level of exit discharge in buildings where accessibility is required and the accessible means of egress uses a stairway. The most important exception: areas of refuge are NOT required in buildings equipped throughout with an NFPA 13 automatic sprinkler system. Most new commercial buildings required to be fully sprinklered eliminate the area of refuge requirement through this exception. NFPA 13R and 13D systems do not qualify for this exception.

Do all toilet rooms in a building need to be accessible?

Yes, as a general rule. IBC §1109.2 requires that each toilet room be accessible when toilet rooms are provided. A single accessible toilet room on the ground floor does not satisfy the requirement for toilet rooms on upper floors. Narrow exceptions exist for single-occupant toilet rooms accessed only through a private office that is not required to be accessible.

What is the difference between a Type A and Type B accessible dwelling unit?

Type A units (ICC A117.1 §1003) provide a higher level of accessibility — maneuvering clearances comparable to public accommodations, accessible plumbing fixtures and hardware, and accessible routes between all habitable spaces. They are required in 2% of units in elevator-served Group R-2 buildings of four or more stories. Type B units (ICC A117.1 §1004) provide a baseline visitability level broadly consistent with Fair Housing Act guidelines — wider door clear widths, accessible routes into the unit, and accessible bathroom access. Type B units are required in all ground-floor units of elevator-served R-2 buildings not required to be Type A.

What is the accessible route requirement between floors in a multi-story building?

IBC §1104.4 requires an accessible route connecting all accessible stories. The accessible route between floors is typically an elevator, ramp, or compliant platform lift. An exception permits floors above or below the accessible level to be exempt when the aggregate area of those stories is 3,000 square feet or less and the occupancy is not Group A, B, M, or R-1. In practice, most multi-story commercial buildings are required to provide elevator service to all floors.

Conclusion

IBC Chapter 11 sets the mandatory accessibility baseline for every new building in the United States — from the accessible route on the site through the accessible parking spaces, the accessible entrance, every toilet room, every floor, and every occupied space in the building. The framework is default-accessible with specific, enumerated exceptions.

Designing to Chapter 11 requires fluency in three parallel documents: the IBC for scoping, ICC A117.1 for dimensions, and the ADA for civil rights obligations that run independent of the permit process. Jurisdictional amendments — particularly in California, New York, and Texas — add additional requirements that exceed the IBC baseline.

For the complete technical ADA and ICC A117.1 dimension-by-dimension guide covering door clearances, ramp design, toilet room layouts, reach ranges, accessible seating, and Fair Housing Act requirements, see: ADA accessibility requirements

For accessible means of egress — areas of refuge, accessible stairways, and elevator requirements — see the full egress framework in:

IBC means of egress