A117.1 Section 1104
Lessons 9 and 10 covered Accessible and Type A units, both built to a near-complete accessible spec from day one, with only the details differing between them. Type B units, covered by Section 1104, are a different kind of tier. The standard says its Type B criteria are intended to be consistent with the intent of HUD's Fair Housing Accessibility Guidelines and to supplement, not replace, Accessible and Type A units (Section 102.1). Rather than a fully accessible unit, Type B aims at a usable baseline: a unit a visitor can enter and get around in, and that a resident can use, without every fixture already built to the fuller Accessible or Type A numbers. This lesson also introduces Type C units briefly and closes with a side-by-side look at how the three main tiers compare.
Because Type B is meant to supplement Accessible and Type A units, a larger project may call for Type B in many more units than for either of the others. How many units of each type a project needs is set by the scoping provisions of the adopting authority (Section 202), not by A117.1. Where Type B applies to many units, understanding where its numbers are smaller than the general figures matters for keeping an estimate accurate across the whole building, not just the handful of Accessible or Type A units.
Type B has its own clear floor space, 30 inches by 48 inches (Section 1104.1.1), where Section 305.3.1 sets 52 inches by 30 inches for new buildings generally. Type B's doorway clear-width minimum is also its own number, 31-3/4 inches (Section 1104.5.2.1), distinct from the 32 inch general minimum in Section 404.2.2. Neither figure is a rounding error; both are Type B's own, smaller numbers written directly into Section 1104.
Section 1104.5.1 sends the primary entrance door to Section 404 but relaxes some maneuvering clearances. For a front approach, the dimension perpendicular to the door is 48 inches minimum, instead of the general 52 inches for new buildings, on the push side of a swinging door, at a sliding or folding door, and at a doorway without a door. Other approaches, and the front approach on the pull side of a swinging door (60 inches), are not changed. In those cases a Type B unit's front door needs somewhat less floor space than an Accessible or Type A unit's entrance does.
Type B units do not have grab bars installed from day one. Section 1104.11.1 requires reinforcement, blocking built into the walls so grab bars and shower seats can be added later without opening up finished walls, at water closets, bathtubs, and shower compartments, with a few exceptions such as a room holding only a lavatory and a water closet that does not contain the only lavatory or water closet on the accessible level. Section 1104.11.3 then gives a project a separate choice about fixture clearances. Under Option A, every toilet and bathing area provided must meet the Option A provisions at each fixture. Under Option B, only one toilet and bathing area must meet the Option B provisions: one of each fixture provided, in a single toilet and bathing area so travel between them does not pass through other parts of the unit, with the lavatory front 34 inches maximum above the floor. Either way, the reinforcement requirement applies, so the option a project chooses changes what an inspector measures at the fixtures, not whether wall blocking is expected.
Type B's water closet clearance is 48 inches minimum wide by 56 inches minimum deep, or 66 inches minimum deep where a forward approach is provided (Section 1104.11.3.1.2.2), with the water closet centerline 16 to 18 inches from one side of the clearance. That 48 inch width is narrower than the 60 inch width Accessible and Type A units both require, and it is one of the most concrete differences among the three tiers. A water closet clearance that would fail an Accessible or Type A unit at 48 inches wide is exactly what Type B calls for, although Type B also lets a project use the Type A clearance in its place.
Type B's kitchen clearance numbers match Type A's and Section 804's: 40 inches minimum between opposing counters, appliances, or walls, and 60 inches minimum where counters, appliances, or cabinets are on three contiguous sides, with an island exception. Where Type B differs is that its appliance provisions are written as Type B's own clear floor space rules in Section 1104.12.2, such as a refrigerator/freezer clear floor space centerline offset of 15 inches maximum at a forward approach and 24 inches maximum at a parallel approach, and Section 1104.12 has no counterpart to Type A's accessible work surface or sink height provisions. An estimator should cite 1104.12 for a Type B kitchen, not 1103.12.
Section 1104.1.2 gives relief on mailbox reach range specifically. The general maximum unobstructed side reach in Section 308.3.1 is 48 inches. For a mailbox serving a Type B unit, that maximum rises to 54 inches, a narrow but real allowance that would not apply to a side reach requirement anywhere else in the unit.
Clear floor space: 30 in. by 48 in., versus the general 30 by 52 in. minimum for new buildings (Sec.1104.1.1). Doorway clear width: 31-3/4 in. min, versus 32 in. general. Primary entrance maneuvering clearance, front approach: 48 in. min on the push side of swinging doors, at sliding or folding doors, and at doorways without doors, versus 52 in. general for new buildings. Grab bars and shower seats: reinforcement (blocking) only, in either option (Sec.1104.11.1). Toilet and bathing areas: Option A applies to every area, Option B to one area with one of each fixture (Sec.1104.11.3). Water closet clearance: 48 in. min wide x 56 in. min deep (66 in. deep at a forward approach), narrower than the 60 in. width Accessible and Type A units require; centerline 16-18 in. from one side of the clearance. Kitchen clearance: 40 in./60 in., matching Type A and Sec.804, with Type B's own appliance rules under Sec.1104.12. Mailbox reach: 54 in. max side reach, versus the general 48 in. max.
Section 1105 defines a lighter tier, Type C or "Visitable" units, which the standard describes as minimal accessibility features for one and two family dwelling units and townhouses not covered by HUD's Fair Housing Accessibility Guidelines. A Type C unit needs at least one unit entrance on a circulation path from a public street or sidewalk, a driveway, or a garage, an entrance level with one habitable space of at least 70 square feet, and a toilet room or bathroom on the entrance level unless that level has less than 120 square feet of habitable space. Type C is background awareness for GCHS staff, not a full requirement set to memorize the way Accessible, Type A, and Type B are; whether it applies depends on the adopting authority's scoping, and this course does not devote a full lesson to it.
| Feature | Accessible | Type A | Type B |
|---|---|---|---|
| Entrance/route rigor | Section 404 applies, with the short exception list in 1102.5 | Same pattern as Accessible, with Type A's own exception list | Relaxed: smaller clear floor space and doorway width, 48 in. front-approach clearance at the entrance in some cases |
| Water closet clearance width | 60 in. min | 60 in. min (identical) | 48 in. min (narrower) |
| Kitchen clearance | Section 804: 40 in., 60 in. U-shaped | Same 40/60 in., written in Sec.1103.12, plus adjustable-height and removable-cabinetry allowances | Same 40/60 in., written in Sec.1104.12, with Type B's own appliance clear floor space rules |
| Grab bars | Installed, as part of at least one full accessible bathroom | Reinforcement (blocking) for future grab bars and shower seats, Sec.1103.11.1 | Reinforcement (blocking) only, Sec.1104.11.1; Option A or B sets the fixture clearances |
Why this matters for GCHS
On a larger multifamily rehab project, Type B may be the tier covering many of the units, so a GCHS estimator who only checks Accessible or Type A numbers can misjudge much of the building. Confirming which toilet and bathing option, A or B, a project has actually chosen under 1104.11.3 changes which fixture clearances an inspector should measure, and since Type B requires reinforcement rather than installed grab bars, blocking without bars is the required outcome, not a deficiency. GCHS's construction management and inspection role means catching that distinction on paper before a wall gets closed up, not after.
1. What best describes Type B units among the dwelling-unit categories?
2. What is the Type B clear floor space minimum, compared to the general Section 305.3.1 number for new buildings?
3. What is the Type B doorway clear-width minimum?
4. A Type B unit's primary entrance door is approached from the front, on the push side of a swinging door. How does the required maneuvering clearance perpendicular to the door compare with the general figure for new buildings?
5. A GCHS estimator is scoping a Type B multifamily rehab bathroom. The plans show blocking in the walls for future grab bars but no grab bars installed. Does this satisfy the Type B grab bar provision?
6. What choice does Section 1104.11.3 give a Type B project for its toilet and bathing areas?
7. What is the Type B water closet clearance, compared to Accessible and Type A?
8. A GCHS inspector measures a Type B unit's water closet clearance, approached from the side, at 52 inches wide by 56 inches deep. Does this meet the Type B minimum?
9. How do Type B kitchen clearance numbers compare to Type A's?
10. What reach-range relief does Section 1104 give for a Type B unit's mailbox?
11. What is required for a Type C (Visitable) unit under Section 1105?
12. A GCHS staff member is reviewing plans for a small addition with 90 square feet of entrance-level habitable space, built to the Type C standard. Is an accessible bathroom required?
13. Which dwelling-unit type has its own smaller doorway clear-width minimum, 31-3/4 inches?
14. Comparing Accessible, Type A, and Type B water closet clearance widths, which statement is correct?