UFAS 4.2, 4.4, 4.5
This lesson covers the dimensions UFAS treats as building blocks, numbers that reappear once you reach later chapters on doors, toilet rooms, and dwelling units. Section 4.2, Space Allowances and Reach Ranges, sets how much room a wheelchair user needs to move and turn, and how high or low a control can be mounted and still be usable. Section 4.4, Protruding Objects, keeps hazards out of the path of a person walking with a cane or who has low vision. Section 4.5, Ground and Floor Surfaces, sets what a walking surface is made of and how a change in level along it is handled. Every number below carries its UFAS section number so it can be checked directly.
Section 4.2.1 sets the minimum clear width for a single wheelchair at 32 inches at a single point, such as a doorway, and 36 inches continuously. Section 4.2.2 sets the minimum width for two wheelchairs to pass each other at 60 inches. A GCHS rehab hallway narrowed to less than 36 inches over any real distance fails 4.2.1, even if every doorway along it is wide enough on its own.
Section 4.2.3 requires a clear space for a full 180-degree wheelchair turn: either a 60-inch diameter circle, or a T-shaped space fitting within a 60-by-60-inch square, with the T's arms and stem 36 inches wide minimum, as drawn in UFAS Fig. 3(b). This is what lets a wheelchair user reverse direction inside a room rather than being able to enter but not turn back around, and it reappears inside bathrooms and kitchens covered later in this course.
Section 4.2.4.1 sets the minimum stationary clear floor space at 30 by 48 inches, sized for either a forward or a parallel approach to a fixture. Section 4.2.4.2 requires one full unobstructed side of that space to adjoin or overlap an accessible route, or to adjoin another wheelchair clear floor space, so it is actually reachable rather than isolated. If the space is in an alcove or otherwise confined on all or part of three sides, extra maneuvering clearance applies as shown in UFAS Fig. 4(d) and (e). Per those figures, a shallow alcove, 24 inches or less deep for a front approach or 15 inches or less for a side approach, needs no extra allowance, while a deeper alcove needs additional width or length beyond the 30-by-48 minimum. Section 4.2.4.3 requires the floor to meet the surface rules in Section 4.5, covered later in this lesson.
Where the clear floor space allows only a forward approach, Section 4.2.5 sets the maximum high forward reach at 48 inches and the minimum low forward reach at 15 inches above the floor, the highest and lowest a control can be mounted and still be reachable from a seated position reaching straight ahead. Reaching over an obstruction, such as a counter with a knee space underneath, changes the number, as shown in UFAS Fig. 5(b): where the obstruction is 20 to 25 inches deep, the maximum forward reach drops to 44 inches.
Where the clear floor space allows a parallel approach, Section 4.2.6 sets the maximum high side reach at 54 inches and the minimum low side reach at 9 inches above the floor. Reaching sideways over an obstruction up to 24 inches deep and 34 inches high drops the maximum to 46 inches, as shown in UFAS Fig. 6(c). This is a real difference from the 2010 ADA Standards: Section 308.3.1 there caps unobstructed side reach at 48 inches maximum with a 15-inch minimum, both different from UFAS's 9-to-54-inch range. A fixture mounted to satisfy the ADA's 48-inch maximum also satisfies UFAS, but one mounted at UFAS's full 54-inch maximum would not meet the ADA figure, so a GCHS project using the 2010 ADA alternative under HUD's 2014 notice needs the ADA number here, not the UFAS one.
Section 4.4.1 limits how far an object projecting from a wall, with its leading edge between 27 and 80 inches above the floor, can protrude into a walk, hall, or aisle: no more than 4 inches. The rule protects people using a long cane, which sweeps the lower path but will not detect something cantilevered out at chest or head height. An object at or below 27 inches can protrude further, since a cane sweep or wheelchair footrest reaches it first. A free-standing object on a post can overhang up to 12 inches within that same band. Section 4.4.2 separately requires 80 inches of clear head room through any circulation space, and a barrier to warn blind or visually impaired people where the vertical clearance of an area adjoining an accessible route drops below that.
Section 4.5.1 requires ground and floor surfaces on accessible routes to be stable, firm, and slip-resistant. Section 4.5.2 governs how abrupt a level change can be: up to 1/4 inch is allowed with no edge treatment; between 1/4 and 1/2 inch requires a bevel sloped no steeper than 1:2; anything greater than 1/2 inch must be handled as a ramp, curb ramp, or other sloped transition, not a simple lip. Doorway thresholds have their own limits in Section 4.13.8, covered in Lesson 5. A 3/4-inch vertical step in a hallway or room floor is a common, easy-to-miss failure on GCHS rehab sites.
Section 4.5.3 caps carpet pile height at 1/2 inch and requires carpet to be securely attached, with a firm cushion, pad, or backing or none, with exposed edges fastened and trimmed along their full length. Carpet tile has its own limit: the combined thickness of pile, cushion, and backing may not exceed 1/2 inch, so a thick pad or backing under an otherwise low-pile carpet tile can push it over the limit. Section 4.5.4 limits grating openings to 1/2 inch in the smaller dimension, and elongated openings, such as a slotted floor drain, must run perpendicular to the dominant direction of travel so a caster or cane tip cannot drop into a long slot.
Wheelchair passage: 32 in. at a point, 36 in. continuous (4.2.1). Two wheelchairs passing: 60 in. (4.2.2). Turning space: 60 in. circle, or T-shape in a 60 by 60 in. square with 36 in. arms (4.2.3). Clear floor space: 30 by 48 in. (4.2.4.1). Forward reach: 48 in. max, 15 in. min; 44 in. max over a 20-25 in. deep obstruction (4.2.5). Side reach: 54 in. max, 9 in. min; 46 in. max over a 24 in. deep, 34 in. high obstruction (4.2.6). Protruding objects: 4 in. max between 27 and 80 in. high; 80 in. min headroom (4.4). Level changes: 1/4 in. unramped, 1/4-1/2 in. beveled at 1:2, over 1/2 in. needs a ramp (4.5.2). Carpet pile: 1/2 in. max; carpet tile 1/2 in. max combined pile, cushion, and backing (4.5.3). Grating openings: 1/2 in. max (4.5.4).
Why this matters for GCHS
These are the numbers a GCHS estimator or inspector checks on almost every modification: clear hallway width, a 30-by-48 clear floor space at the new grab bar, reach-range switch height, threshold lip height. Getting 4.2 and 4.5 right at estimating avoids rework later, and the side-reach difference from the 2010 ADA alternative matters directly on any project using that HUD 2014 option, covered fully in Lesson 9.
1. Under Section 4.2.1, what is the minimum clear width for continuous single wheelchair passage?
2. What is the minimum width for two wheelchairs to pass each other under Section 4.2.2?
3. What two turning-space configurations does Section 4.2.3 allow?
4. What is the minimum clear floor or ground space for a stationary wheelchair under Section 4.2.4.1?
5. Under Section 4.2.5, what is the unobstructed high forward reach maximum, and the low forward reach minimum?
6. Reaching forward over an obstruction 20 to 25 inches deep, what does the maximum forward reach become?
7. Under Section 4.2.6, what is the unobstructed high side reach maximum, and the low side reach minimum?
8. How does the 2010 ADA Standards' unobstructed side reach figure (Section 308.3.1) compare to UFAS Section 4.2.6?
9. Under Section 4.4.1, how far can a wall-mounted object with its leading edge between 27 and 80 inches above the floor protrude into a circulation path?
10. What is the minimum clear head room required through a circulation space under Section 4.4.2?
11. Under Section 4.5.2, a change in level of 3/8 inch requires what treatment?
12. A GCHS rehab site has a 3/4-inch unramped vertical change in level in a hallway floor, away from any doorway. Does this comply with Section 4.5.2?
13. Under Section 4.5.3, what is the maximum pile height of carpet used on an accessible floor?
14. Under Section 4.5.4, what is the maximum width of a grating opening, and how should elongated openings be oriented?