CMC Home Accessibility Modification 3 — Questions and Answers
Question 1: When specifying a vertical platform lift (VPL) for indoor use, what is the maximum allowable rise in most US residential building codes without triggering elevator code requirements?
- 48 inches
- 60 inches (Correct answer)
- 72 inches
- 96 inches
Correct answer: 60 inches
Most residential codes allow VPLs to travel up to 60 inches of rise before full elevator code requirements apply.
Question 2: A client reports difficulty operating a round doorknob due to reduced hand strength. What is the most appropriate hardware replacement?
- A padded grip sleeve over the existing knob
- A lever-style door handle operable with a closed fist (Correct answer)
- A magnetic door catch with a pull cord
- A keypad entry lock requiring finger pressure
Correct answer: A lever-style door handle operable with a closed fist
Lever handles comply with ADA operable parts requirements because they can be operated with a closed fist, requiring no grasping or twisting.
Question 3: What does the term 'turning radius' refer to in the context of wheelchair accessibility planning?
- The angle of a ramp surface
- The circular floor area a wheelchair needs to turn 180° or 360° (Correct answer)
- The bend radius of a handrail at a landing
- The pivot range of a stairlift at the top landing
Correct answer: The circular floor area a wheelchair needs to turn 180° or 360°
Turning radius describes the floor space required for a wheelchair to complete a turn; a 60-inch diameter circle accommodates a full 360° turn.
Question 4: Which type of stairlift track configuration is required when a staircase makes a 90-degree turn between floors?
- A straight rail stairlift with a landing transfer
- A curved rail stairlift custom-bent to follow the stairs (Correct answer)
- Two straight stairlifts installed on each stair section with a perch seat between them
- A vertical platform lift installed in the corner of the landing
Correct answer: A curved rail stairlift custom-bent to follow the stairs
Curved rail stairlifts are custom-fabricated to follow the exact geometry of non-straight staircases, including 90-degree turns.
Question 5: What is the recommended mounting height range for light switches and electrical outlets in an accessible home to serve both standing and seated users?
- Switches at 48 inches, outlets at 15 inches
- Switches at 42–48 inches, outlets at 18–48 inches (Correct answer)
- Switches at 36 inches, outlets at 24 inches
- Switches at 54 inches, outlets at 12 inches
Correct answer: Switches at 42–48 inches, outlets at 18–48 inches
Placing switches between 42–48 inches and outlets between 18–48 inches creates an overlapping zone reachable from both standing and seated positions.
Question 6: A client with low vision needs contrast improvements in their home. Which modification provides the most functional benefit at stair edges?
- Painting all walls a uniform neutral color
- Installing contrasting color nosing strips on each stair tread edge (Correct answer)
- Adding overhead recessed lighting every 4 feet along the stairway
- Replacing carpet with polished hardwood for light reflection
Correct answer: Installing contrasting color nosing strips on each stair tread edge
High-contrast nosing strips define the edge of each tread clearly, which is the most critical visual cue for safe stair navigation with low vision.
Question 7: When assessing a bathroom door for wheelchair access, which door type offers the greatest usable floor space inside the bathroom?
- Standard hinged door swinging inward
- Standard hinged door swinging outward
- Pocket door that slides into the wall (Correct answer)
- Bifold door with two panels
Correct answer: Pocket door that slides into the wall
A pocket door slides entirely into the wall cavity, eliminating door swing clearance and maximizing usable floor space in small bathrooms.
CMC Home Accessibility Modification 3
When specifying a vertical platform lift (VPL) for indoor use, what is the maximum allowable rise in most US residential building codes without triggering elevator code requirements?