Chapter V3: Building Blocks

V301 General

V301.1 Scope.  The provisions of Chapter 3 shall apply where required by Chapter 2 or where referenced by a requirement in this document.

V302 Deck Surfaces

V302.1 General.  Deck surfaces shall be stable, firm, and slip resistant and shall comply with V302.

EXCEPTIONS.  Areas of sport activity shall not be required to comply with V302.

Advisory V302.1 General.  A stable surface is one that remains unchanged by contaminants or applied force, so that when the contaminant or force is removed, the surface returns to its original condition.  A firm surface resists deformation by either indentations or particles moving on its surface.  A slip-resistant surface provides sufficient frictional counterforce to the forces exerted in walking to permit safe ambulation.

V302.2 Carpet.  Carpet or carpet tile shall be securely attached and shall have a firm cushion, or backing or no cushion.  Carpet or carpet tile shall have a level loop, textured loop, level cut pile, or level cut/uncut pile texture.  Pile height shall be ½ inch (13 mm) maximum.  Exposed edges of carpet shall be fastened to deck surfaces and shall have trim on the entire length of the exposed edge.  Carpet edge trim shall comply with V303.

Advisory V302.2 Carpet.  Carpets and permanently affixed mats can significantly increase the amount of force (roll resistance) needed to propel a wheelchair over a surface.  The firmer the carpeting and backing, the lower the roll resistance.  A pile thickness up to ½ inch (13 mm) (measured to the backing, or cushion (e.g., padding) if no backing is provided) is allowed, although a lower pile provides easier wheelchair maneuvering.  If a backing or cushion is used, it must be firm.  Preferably, carpet cushion should not be used because the soft cushioning increases roll resistance.

Figure V302.2
Carpet Pile Height
Carpet is shown in cross section with a pile height of 2 inch (13 mm) maximum, measured from the backing.

V302.3 Openings.  Openings in deck surfaces shall not allow passage of a sphere more than ½ inch (13 mm) in diameter except as allowed in V407.4.3 and V409.4.  Elongated openings shall be placed so that the long dimension is perpendicular to the dominant direction of travel.

EXCEPTIONS.  1.  Vehicle tie-downs that are flush with the deck surface and are not located within an onboard accessible route shall not be required to comply with V302.3.

2.  Where the administrative authority determines that larger openings are needed for deck drainage, openings not located within an accessible route shall be permitted to be increased, if the size shall not allow passage of a sphere more than ¾ inch (19 mm) in diameter.

Figure V302.3
Elongated Openings in Deck Surfaces
Elongated openings, such as in a grating, are shown in plan view with openings 2 inch (13 mm) maximum in one dimension.  The other dimension is longer (unspecified) and is perpendicular to the dominant direction of travel.

V303 Changes in Level

V303.1 General.  Where changes in level are permitted in deck surfaces, they shall comply with V303.

EXCEPTIONS.  1.  Areas of sport activity shall not be required to comply with V303.

2.  Vehicle tie-downs that are flush with the deck surface and are not located within an accessible route shall not be required to comply with V303.

V303.2 Vertical.  Changes in level of ¼ inch (6.4 mm) high maximum shall be permitted to be vertical.

Figure V303.2
Vertical Change in Level
Elevation drawing of a change in level between the surfaces of two parallel planes with a vertical edge that is ¼ inch (6.4 mm) high maximum.

V303.3 Beveled.  Changes in level between ¼ inch (6.4 mm) high minimum and ½ inch (13 mm) high maximum shall be beveled with a slope not steeper than 1:2.

Advisory V303.3 Beveled.  A change in level of ½ inch (13 mm) is permitted to be ¼ inch (6.4 mm) vertical plus ¼ inch (6.4 mm) beveled.  However, in no case may the combined change in level exceed ½ inch (13 mm).  Changes in level exceeding ½ inch (13 mm) must comply with V405 (Ramps) or V406 (Curb Ramps).

Figure V303.3
Beveled Change in Level
(a) Elevation drawing of a change in level ½ inches (13 mm) high with the first ¼ inch (6.4 mm) being vertical and the remaining ¼ inches (6.4 mm) being beveled with a slope of 1:2.  (b) Elevation drawing of a change in level ½ inches (13 mm) high that is beveled with a slope of 1:2.

V303.4 Ramps.  Changes in level greater than ½ inch (13 mm) high shall be ramped, and shall comply with V405 or V406.

V304 Turning Space

V304.1 General.  Turning space shall comply with V304.

V304.2 Deck Surfaces.  Deck surfaces of a turning space shall comply with V302.  Changes in level are not permitted.

EXCEPTION.  Slopes not steeper than 1:48 shall be permitted.

Advisory V304.2 Deck Surfaces Exception.  As used in this section, the phrase “changes in level” refers to surfaces with slopes and to surfaces with an abrupt rise exceeding that permitted in Section V303.3.  Such changes in level are prohibited in required clear deck spaces, turning spaces, and in similar spaces where people using wheelchairs and other mobility devices must park their mobility aids such as in wheelchair spaces, or maneuver to use elements such as at doors, fixtures, and telephones.  The exception permits slopes not steeper than 1:48.

V304.3 Size.  Turning space shall comply with V304.3.1 or V304.3.2.

V304.3.1 Circular Space.  The turning space shall be a space of 60 inches (1525 mm) diameter minimum.  The space shall be permitted to include knee and toe clearance complying with V306.

V304.3.2 T-Shaped Space.  The turning space shall be a T-shaped space within a 60 inch (1525 mm) square minimum with arms and base 36 inches (915 mm) wide minimum.  Each arm of the T shall be clear of obstructions 12 inches (305 mm) minimum in each direction and the base shall be clear of obstructions 24 inches (610 mm) minimum.  The space shall be permitted to include knee and toe clearance complying with V306 only at the end of either the base or one arm.

Figure V304.3.2
T-Shaped Turning Space
The T shape space is 36 inches (915 mm) wide at the top and stem within a 60 inch by 60 inch (1525 mm by 1525 mm) square.

V304.4 Door Swing.  Doors shall be permitted to swing into turning spaces.

V305 Clear Deck Space

V305.1 General.  Clear deck space shall comply with V305.

V305.2 Deck Surfaces.  Deck surfaces of a clear deck space shall comply with V302.  Changes in level are not permitted.

EXCEPTION.  Slopes not steeper than 1:48 shall be permitted.

V305.3 Size.  The clear deck space shall be 30 inches (760 mm) minimum by 48 inches (1220 mm) minimum.

Figure V305.3
Clear Deck Space
Clear deck space is 30 inches by 48 inches (760 mm by 1220 mm) minimum.

V305.4 Knee and Toe Clearance.  Unless otherwise specified, clear deck space shall be permitted to include knee and toe clearance complying with V306.

V305.5 Position.  Unless otherwise specified, clear deck space shall be positioned for either forward or parallel approach to an element.

Figure V305.5
Position of Clear Deck Space
(a) For a forward approach to an element, a clear deck space, 30 inches by 48 inches (760 mm by 1220 mm) minimum, is shown with the shorter dimension parallel to the wall or element.  (b) For a parallel approach to an element, a clear deck space, 30 inches by 48 inches (760 mm by 1220 mm) minimum, is shown with the longer dimension parallel to the wall or element.

V305.6 Approach.  One full unobstructed side of the clear deck space shall adjoin an accessible route or adjoin another clear deck space.

V305.7 Maneuvering Clearance.  Where a clear deck space is confined on all or part of three sides, additional maneuvering clearance shall be provided in accordance with V305.7.

V305.7.1 Forward Approach.  Where the clear deck space is approached at the short side, the space shall be 36 inches (915 mm) wide minimum where the depth of the confined clear deck space exceeds 24 inches (610 mm).

Figure V305.7.1
Maneuvering Clearance in an Alcove, Forward Approach
For a forward approach, if the depth of the alcove is greater than 24 inches (610 mm), the clear deck space within the alcove must be 36 inches (915 mm) wide minimum.

V305.7.2 Parallel Approach.  Where the clear deck space is approached at the long side, the space shall be 60 inches (1525 mm) wide minimum where the depth of the confined clear deck space exceeds 15 inches (380 mm).

Figure V305.7.2
Maneuvering Clearance in an Alcove, Parallel Approach
For a parallel approach, if the depth of the alcove is greater than 15 inches (380 mm), then the length of the clear deck space within the alcove must be 60 inches (1525 mm) minimum.

V306 Knee and Toe Clearance

V306.1 General.  Where space beneath an element is included as part of clear deck space or turning space, the space shall comply with V306.  Additional space shall not be prohibited beneath an element but shall not be considered as part of the clear deck space or turning space.

Advisory V306.1 General.  Clearances are measured in relation to the usable clear deck space, not necessarily to the vertical support for an element.  When determining clearance under an object for required turning or maneuvering space, care should be taken to ensure the space is clear of any obstructions.

V306.2 Toe Clearance.

V306.2.1 General.  Space under an element between the finish deck surface and 9 inches (230 mm) above the finish deck surface shall be considered toe clearance and shall comply with V306.2.

V306.2.2 Maximum Depth.  Toe clearance shall extend 25 inches (635 mm) maximum under an element.

V306.2.3 Minimum Required Depth.  Where toe clearance is required at an element as part of a clear deck space, the toe clearance shall extend 17 inches (430 mm) minimum under the element.

V306.2.4 Additional Clearance.  Space extending greater than 6 inches (150 mm) beyond the available knee clearance at 9 inches (230 mm) above the finish deck surface shall not be considered toe clearance.

V306.2.5 Width.  Toe clearance shall be 30 inches (760 mm) wide minimum.

Figure V306.2
Toe Clearance
(a) Elevation.  Toes of a person in a wheelchair are shown extending for a maximum depth of 6 inches (150 mm) under an object that is 9 inches (230 mm) high minimum.  (b) Plan.  Toe clearance at an element, as part of clear deck space, shall extend 17 to 25 inches (430 to 635 mm) under the element.  The clear deck space is 30 inches (760 mm) wide minimum

V306.3 Knee Clearance.

V306.3.1 General.  Space under an element between 9 inches (230 mm) and 27 inches (685 mm) above the finish deck surface shall be considered knee clearance and shall comply with V306.3.

V306.3.2 Maximum Depth.  Knee clearance shall extend 25 inches (635 mm) maximum under an element at 9 inches (230 mm) above the finish deck surface.

V306.3.3 Minimum Required Depth.  Where knee clearance is required under an element as part of a clear deck space, the knee clearance shall be 11 inches (280 mm) deep minimum at 9 inches (230 mm) above the finish deck surface, and 8 inches (205 mm) deep minimum at 27 inches (685 mm) above the finish deck surface.

V306.3.4 Clearance Reduction.  Between 9 inches (230 mm) and 27 inches (685 mm) above the finish deck surface, the knee clearance shall be permitted to reduce at a rate of 1 inch (25 mm) in depth for each 6 inches (150 mm) in height.

V306.3.5 Width.  Knee clearance shall be 30 inches (760 mm) wide minimum.

Figure V306.3
Knee Clearance
(a) Elevation.  Knee clearance is 27 inches (685 mm) high minimum above the deck surface  for a minimum depth of 8 inches (205 mm), measured from the leading edge of the element.  The vertical clearance decreases beyond this depth to a height of 9 inches (230 mm) minimum at depth of 11 inches (280 mm) minimum measured from the leading edge of the element.  (b) Plan.  Combined knee and toe clearance can extend 25 inches (635 mm) maximum under an element.

V307 Protruding Objects

V307.1 General.  Protruding objects shall comply with V307.

V307.2 Protrusion Limits.  Objects with leading edges more than 27 inches (685 mm) and not more than 80 inches (2030 mm) above the finish deck surface shall protrude 4 inches (100 mm) maximum horizontally into the circulation path.

EXCEPTION.  Handrails shall be permitted to protrude 4½ inches (115 mm) maximum.

Advisory V307.2 Protrusion Limits.  When a cane is used and the element is in the detectable range, it gives a person sufficient time to detect the element with the cane before there is body contact.  Elements located on circulation paths, including operable elements, must comply with requirements for protruding objects.  For example, awnings and their supporting structures cannot reduce the minimum required vertical clearance.

Figure V307.2
Limits of Protruding Objects
A frontal view shows a person using a cane walking along a wall.  A wall-mounted object more than 27 inches (685 mm) above the deck surface protrudes no more than 4 inches (100 mm) from the wall surface.  An object overhead provides vertical clearance that is greater than 80 inches (2030 mm).

V307.3 Required Clear Width.  Protruding objects shall not reduce the clear width required for onboard accessible routes.

V307.4 Vertical Clearance.  Vertical clearance shall be 80 inches (2030 mm) high minimum.  Guardrails or other barriers shall be provided where the vertical clearance is less than 80 inches (2030 mm) high.  The leading edge of such guardrail or barrier shall be located 27 inches (685 mm) maximum above the finish deck surface.

EXCEPTIONS.  1.  Door closers and door stops shall be permitted to be 78 inches (1980 mm) minimum above the finish deck surface.

2.  Where doors are required by the administrative authority to have coamings, measurements shall be permitted to be taken from the finish deck surface adjacent to the coamings and not the top of the coamings.

Figure V307.4
Vertical Clearance
A person using a long cane is shown approaching the sloped underside of a staircase.  A portion of the area below the stairs in front of the person has a vertical clearance less than 80 inches (2030 mm).  A railing 27 inches (685 mm) high maximum separates this space from the areas where a vertical clearance at or above 80 inches (2030 mm) is maintained.

V308 Reach Ranges

V308.1 General.  Reach ranges shall comply with V308.

Advisory V308.1 General.  The following table provides guidance on reach ranges for children according to age where vessel elements such as coat hooks, lockers, or operable parts are designed for use primarily by children.  These dimensions apply to either forward or side reaches.  Accessible elements and operable parts designed for adult use or children over age 12 can be located outside these ranges but must be within the adult reach ranges required by V308.

Children’s Reach Ranges
Forward or Side ReachAges 3 and 4Ages 5 through 8Ages 9 through 12
High (maximum) 36 in (915 mm) 40 in (1015 mm) 44 in (1120 mm)
Low (minimum) 20 in (510 mm) 18 in (455 mm) 16 in (405 mm)

V308.2 Forward Reach.

V308.2.1 Unobstructed.  Where a forward reach is unobstructed, the high forward reach shall be 48 inches (1220 mm) maximum and the low forward reach shall be 15 inches (380 mm) minimum above the finish deck surface.

Figure V308.2.1
Unobstructed Forward Reach
A side view is shown of a person suing a wheelchair reaching toward a wall.  The lowest vertical reach point is 15 inches (380 mm) minimum and the highest is 48 inches (1220 mm) maximum.

V308.2.2 Obstructed High Reach.  Where a high forward reach is over an obstruction, the clear deck space shall extend beneath the element for a distance not less than the required reach depth over the obstruction.  The high forward reach shall be 48 inches (1220 mm) maximum where the reach depth is 20 inches (510 mm) maximum.  Where the reach depth exceeds 20 inches (510 mm), the high forward reach shall be 44 inches (1120 mm) maximum and the reach depth shall be 25 inches (635 mm) maximum.

Figure V308.2.2
Obstructed High Forward Reach
Figure (a) shows a person seated in a wheelchair reaching a point on a wall above a protrusion, such as a wall-mounted counter, which is 20 inches (510 mm) deep maximum.  The maximum reach height is 48 inches (1220 mm).  In figure (b), the obstruction is more than 20 inches (510 mm) deep, with 25 inches (635 mm) the maximum depth.  The maximum reach height is 44 inches (1120 mm).

V308.3 Side Reach.

V308.3.1 Unobstructed.  Where a clear deck space allows a parallel approach to an element and the side reach is unobstructed, the high side reach shall be 48 inches (1220 mm) maximum and the low side reach shall be 15 inches (380 mm) minimum above the finish deck surface.

EXCEPTION.  An obstruction shall be permitted between the clear deck space and the element where the depth of the obstruction is 10 inches (255 mm) maximum.

Figure V308.3.1
Unobstructed Side Reach
The drawing shows a frontal view of a person using a wheelchair making a side reach to a wall.  The depth of reach is 10 inches (255 mm) maximum.  The vertical reach range is 15 inches (380 mm) minimum to 48 inches (1220 mm) maximum.

V308.3.2 Obstructed High Reach.  Where a clear deck space allows a parallel approach to an element and the high side reach is over an obstruction, the height of the obstruction shall be 34 inches (865 mm) maximum and the depth of the obstruction shall be 24 inches (610 mm) maximum.  The high side reach shall be 48 inches (1220 mm) maximum for a reach depth of 10 inches (255 mm) maximum.  Where the reach depth exceeds 10 inches (255 mm), the high side reach shall be 46 inches (1170 mm) maximum for a reach depth of 24 inches (610 mm) maximum.

EXCEPTION.  The top of washing machines and clothes dryers shall be permitted to be 36 inches (915 mm) maximum above the finish deck surface.

Figure V308.3.2
Obstructed High Side Reach
In figure (a), the drawing shows a frontal view of a person using a wheelchair making a side reach to a wall over an obstruction.  The depth of reach is 10 inches (255 mm) maximum over an obstruction 34 inches (865 mm) maximum in height.  The vertical reach range is shown as 48 inches (1220 mm) maximum.  In figure (b), the drawing shows a frontal view of a person using a wheelchair making a side reach to a wall over an obstruction.  The depth of reach is greater than 10 inches (255 mm) minimum to 24 inches (610 mm) maximum over an obstruction 34 inches (865 mm) maximum in height.  The vertical reach range is shown as 46 inches (1170 mm) maximum.

V309 Operable Parts

V309.1 General.  Operable parts shall comply with V309.

V309.2 Clear Deck Space.  A clear deck space complying with V305 shall be provided.

V309.3 Height.  Operable parts shall be placed within one or more of the reach ranges specified in V308.

V309.4 Operation.  Operable parts shall be operable with one hand and shall not require tight grasping, pinching, or twisting of the wrist.  The force required to activate operable parts shall be 5 pounds (22.2 N) maximum.