1.3 Existing Buildings: IEBC Section 306 Alterations, Additions, and Changes of Occupancy
Key Takeaways
IEBC 306.7 requires altered facilities to comply with IBC Chapter 11 and A117.1 unless technically infeasible, and then to provide access to the maximum extent technically feasible.
An alteration may not decrease accessibility below new-construction requirements at the time of the alteration (2021 IEBC 306.3.1; 2024 IEBC 306.2.1).
When an alteration affects or contains a primary function area, the route to it, including the toilet facilities and drinking fountains serving it, must be accessible, capped at 20 percent of the alteration cost by Exception 1.
Additions are new construction; an addition that affects or contains a primary function area also triggers the 306.7.1 route requirement.
Accessible means of egress are not required to be added in existing facilities, and Type B units are not required where the work area is 50 percent or less of the building.
1.3 Existing Buildings: IEBC Section 306 Alterations, Additions, and Changes of Occupancy
Accessibility in Existing Buildings is the largest subtopic in the General Administrative domain (4% of the exam). The governing provisions are in IEBC Section 306, which applies under every IEBC compliance method. The 2021 and 2024 IEBC both use Section 306, but the 2024 edition renumbered several subsections; both numbers are given below.
The Framework
| Topic | 2021 IEBC | 2024 IEBC | Rule |
|---|---|---|---|
| Scope | 306.1 | 306.1 | Applies to maintenance and repair, change of occupancy, additions and alterations, including historic buildings |
| Design | 306.2 | 306.3 | Comply with the IEBC and the alteration and existing building provisions of A117.1 |
| Maintenance | 306.3 | 306.2 (General) | Accessible facilities are maintained accessible; required accessible means of egress are maintained during construction |
| Prohibited reduction | 306.3.1 | 306.2.1 | An alteration may not decrease accessibility below new-construction requirements at the time of the alteration |
| Extent | 306.4 | 306.4 | An alteration never requires more accessibility than new construction would |
| Change of occupancy | 306.5 | 306.5 | Comply with 306.7; Type B units not required where the work area is 50% or less |
| Additions | 306.6 | 306.6 | New-construction rules apply; primary function additions trigger 306.7.1 |
| Alterations | 306.7 | 306.7 | Comply with IBC Chapter 11 and A117.1 unless technically infeasible |
Prohibited Reduction
The prohibited-reduction rule compares the altered condition with new-construction requirements at the time of the alteration. Replacing a compliant lever handle with a knob, removing grab bars, or narrowing an accessible door below 32 in. clear is prohibited. The same section limits the count: the number of accessible elements need not exceed what new construction would require.
Technically Infeasible
Section 306.7 requires altered elements to comply "unless technically infeasible. Where compliance with this section is technically infeasible, the alteration shall provide access to the maximum extent technically feasible." Cost is not part of the technically infeasible definition. Cost enters the IEBC only through the 20% exception discussed below.
Primary Function Areas (306.7.1)
Where an alteration affects the accessibility to, or contains an area of primary function, the route to the primary function area shall be accessible. The accessible route to the primary function area shall include toilet facilities and drinking fountains serving the area of primary function.
A primary function is a major activity for which the facility is intended: a bank customer lobby, a cafeteria dining area, conference rooms, offices and other work areas. The definition expressly excludes mechanical rooms, boiler rooms, supply storage rooms, employee lounges or locker rooms, janitorial closets, entrances, corridors and restrooms.
The Five Exceptions
| Exception | The route requirement does not apply to |
|---|---|
| 1 | Costs above 20 percent of the cost of the alterations affecting the primary function area (2024 wording: the costs of the accessible route, toilet facilities and drinking fountains) |
| 2 | Alterations limited solely to windows, hardware, operating controls, electrical outlets and signs |
| 3 | Alterations limited solely to mechanical systems, electrical systems, fire protection systems and abatement of hazardous materials |
| 4 | Alterations undertaken primarily to increase the accessibility of the facility |
| 5 | Altered areas limited to Type B dwelling and sleeping units |
Worked Example
An owner remodels a retail sales floor (a primary function area) for $180,000. The route from the entrance to the sales floor has a non-compliant door and the toilet room serving the floor lacks grab bars and an accessible lavatory.
- The sales floor itself must comply fully, to the maximum extent technically feasible. The 20% limit never reduces the work on the altered area itself.
- Route, toilet room and drinking fountain upgrades are required, but Exception 1 says their cost is not required to exceed 0.20 x $180,000 = $36,000.
- If full upgrades cost $30,000, all must be done. If they cost $52,000, at least $36,000 must be spent and the jurisdiction will expect the spending to improve the route first.
Note
The federal ADA regulation for public accommodations (28 CFR 36.403) contains a separate disproportionality rule with a listed priority order (entrance, route, toilet rooms, telephones, drinking fountains) and an aggregation rule for a series of small alterations. Those details are federal law, not IEBC text. On the ICC 21 exam, answer from IEBC 306.7.1 and its five exceptions.
Additions (306.6)
Provisions for new construction apply to additions. In addition, "an addition that affects the accessibility to, or contains an area of, a primary function shall comply with the requirements in Section 306.7.1." The addition is built to new-construction rules with no cost cap, while the route through the existing building that serves a new primary function area is subject to 306.7.1 and its 20% exception. The 2024 IEBC added 306.6.1, requiring at least one accessible means of egress from an addition where IBC 1009.1 requires it, with relief in 306.6.1.1 for additions built only to house an elevator.
Change of Occupancy (306.5)
A building that undergoes a change of group or occupancy complies with Section 306.7, so the altered-facility rules, including the primary function route requirement, apply to the work. The exception releases Type B units in a change of occupancy combined with alterations where the work area is 50 percent or less of the aggregate building area. Local amendments sometimes add a minimum feature list for a complete change of occupancy; answer from the model IEBC text unless the question states an amendment.
Specific Alteration Rules
| Topic | 2021 | 2024 | Rule |
|---|---|---|---|
| Accessible means of egress | 306.7.2 | 306.7.2 | Not required to be added in existing facilities |
| Type A units | 306.7.3 | 306.7.3 | Individually owned Type A units in R-2 may meet Type B criteria |
| Type B units | 306.7.4 | 306.7.4 | Not required where the work area is 50% or less of the building |
| Entrances | 306.7.5 | 306.7.5 | An altered inaccessible entrance need not become accessible if the facility already has an accessible entrance, unless 306.7.1 requires it; IBC 1112 signs required |
| Exterior routes | 306.7.6 | 306.7.6 | Exterior accessible routes, including curb ramps, 36 in. minimum width |
| Elevators | 306.7.7 | 306.7.7 | Altered elements comply with ASME A17.1, including elevators on the same hall call |
| LULA elevators | Not separately listed | 306.7.8 | Permitted as part of an accessible route |
| Platform lifts | 306.7.8 | 306.7.9 | Lifts installed per ASME A18.1 permitted as part of an accessible route |
| New stairway or escalator | 306.7.9 | 306.7.10 | Where none existed and major structural modification is needed, an accessible route between the levels is required |
| Toilet rooms | 306.7.11 | 306.7.12 | If altering existing rooms is technically infeasible, one accessible single-user or family/assisted-use room on the same floor and in the same area, with directional signs |
| Bathing rooms | 306.7.12 | 306.7.13 | Same approach for bathing rooms |
| Dressing and locker rooms | 306.7.14 | 306.7.16 | One accessible room on the same level where technically infeasible at the same location |
| Amusement rides | 306.7.15 | 306.7.17 | Rides altered beyond the manufacturer's design comply as new |
Section 306.7.10 (2021) and 306.7.11 (2024) set unit counts: Accessible-unit requirements apply only to the units being altered or added; Type A requirements apply where more than 20 Group R-2 units are altered or added; Type B requirements apply where four or more units are added, or where units are altered and the work area exceeds 50% of the building.
A primary function area in an existing office building is altered at a cost of $240,000. The route to the area and the toilet rooms serving it need $61,000 of work to comply. Under IEBC 306.7.1, what is the minimum the owner is required to spend on that route work?
$24,000, because the cap is 10 percent
$48,000, the 20 percent limit in Exception 1
$61,000, because the 20 percent limit applies only to additions
Nothing, because toilet rooms are not primary function areas
A building owner replaces only the rooftop HVAC units and the electrical service of an existing office building. What does IEBC 306.7.1 require for the route to primary function areas?
An accessible entrance, because every alteration triggers the entrance requirement
Upgrades up to 20 percent of the mechanical and electrical cost
Nothing, because alterations limited solely to mechanical and electrical systems are excepted
A full accessible route including new elevators
An existing four-story office building without an accessible means of egress is being altered on its third floor. What does the IEBC require regarding accessible means of egress?
Two accessible means of egress must be added from the altered third floor to grade
An area of refuge must be built at each stairway serving the altered floor
None; IEBC 306.7.2 does not require them to be added in existing facilities
An exterior area for assisted rescue must be provided at grade
Sections you finish are checked off in the contents.