(A) Means of egress. All dwellings shall be provided with a means of egress as provided in this section. The means of egress shall provide a continuous and unobstructed path of vertical and horizontal egress travel from all portions of the dwelling to the exterior of the dwelling at the required exterior egress door, without requiring travel through a garage.
(B) Egress door. Not less than one exterior egress door shall be provided for each dwelling unit. The egress door shall be side-hinged, and shall provide a clear width of not less than 32 inches, where measured between the face of the door and the stop, with the door open 90 degrees. The clear height of the door opening shall be not less than 78 inches in height, measured from the top of the threshold to the bottom of the stop. Other exterior doors shall not be required to comply with these minimum dimensions. Egress doors shall be readily openable from inside the dwelling without the use of a key or special knowledge or effort.
(C) Floors and landings at exterior doors.
(1) (a) General requirements. There shall be a landing or floor on each side of each exterior door.
1. The width of each landing shall be not less than the door served.
2. Every landing shall have a dimension of not less than 36 inches, measured in the direction of travel. The slope at exterior landings shall not exceed one quarter unit vertical in 12 units horizontal (2% slope).
(b) Exception. Exterior balconies less than 60 square feet and only accessible from a door are permitted to have a landing with a dimension of less than 36 inches, measured in the direction of travel.
(2) Floor elevations at the required egress doors.
(a) General requirement. Landings or finished floors at the required egress door shall be not more than one and one-half inches lower than the top of the threshold.
(b) Exception. The exterior landing or floor shall be not more than eight and one-quarter inches below the top of the threshold, provided the door does not swing over the landing or floor. Where exterior landings or floors serving the required egress door are not at grade, they shall be provided with access to grade by means of a ramp or a stairway.
(3) Floor elevations for other exterior doors.
(a) General requirement. Doors other than the required egress door shall be provided with landings or floors not more than eight and one-quarter inches below the top of the threshold.
(b) Exception. A landing is not required where a stairway is located on the exterior side of the door, provided that the door does not swing over the stairway.
(4) Storm and screen doors. Storm and screen doors shall be permitted to swing over exterior stairs and landings.
(D) Hallways.
(1) General requirement. The width of a hallway shall be not less than three feet, measured from the finished surface of the walls.
(2) Interior egress doors. All doors providing egress from habitable rooms shall have nominal dimensions of two feet, six inches width by six feet, eight inches height. Interior egress doors shall be readily openable from the side from which egress is to be made without the use of a key or special knowledge or effort.
(E) Stairways.
(1) Width.
(a) General requirements. Stairways shall be not less than 36 inches in clear width at all points above the permitted handrail height and below the required headroom height. Handrails shall not project more than four and one-half inches on either side of the stairway, and the clear width of the stairway at and below the handrail height, including treads and landings, shall be not less than 31½ inches where a handrail is installed on one side, and 27 inches where handrails are provided on both sides.
(b) Exceptions.
1. The width of spiral stairways.
2. Stairways not required for egress shall be permitted to be a minimum width of 26 inches.
(2) Headroom.
(a) General requirement. The headroom in stairways shall be not less than six feet, eight inches, measured vertically from the sloped line adjoining the tread nosing or from the floor surface of the landing or platform on that portion of the stairway.
(b) Exceptions.
1. Where the nosings of treads at the side of a flight extend under the edge of a floor opening through which the stair passes, the floor opening shall be allowed to project horizontally into the required headroom not more than four and three-quarters inches.
2. The headroom for spiral stairways.
(3) Vertical rise. A flight of stairs shall not have a vertical rise larger than 147 inches between floor levels or landings.
(4) Stair treads and risers. Stair treads and risers shall meet the requirements of this section. For the purposes of this section, dimensions and dimensioned surfaces shall be exclusive of carpets, rugs or runners.
(a) Risers. The riser height shall be not more than eight and one-quarter inches. The riser shall be measured vertically between leading edges of the adjacent treads. The greatest riser height within any flight of stairs shall not exceed the smallest by more than three-eighths inch. The top and bottom riser of interior stairs shall not exceed the smallest riser within that stair run by more than three-quarters inch. The height of the top and bottom riser of the interior stairs shall be measured from the permanent finished surface (carpet excluded). Where the bottom riser of an exterior stair adjoins an exterior walk, porch, driveway, patio, garage floor or finish grade, the height of the riser may be less than the height of the adjacent risers.
(b) Treads.
1. General requirements. The minimum tread depth shall be not less than nine inches. The tread depth shall be measured horizontally between the vertical planes of the foremost projection of adjacent treads, and at a right angle to the tread’s leading edge. The greatest tread depth within any flight of stairs shall not exceed the smallest by more than three-eighths inch.
2. Winder treads. Winder treads shall have a tread depth of not less than nine inches, measured between the vertical planes of the foremost projection of adjacent treads at the intersections with the walkline. Winder treads shall have a tread depth of not less than four inches at any point within the clear width of the stair. Within any flight of stairs, the largest winder tread depth at the walkline shall not exceed the smallest winder tread by more than three-eighths inch.
(c) Nosings.
1. General requirements. The radius of curvature at the nosing shall be not greater than nine-sixteenths inch. A nosing projection not less than three-quarters inch and not more than one and one-quarter inches shall be provided on stairways with solid risers. The greatest nosing projection shall not exceed the smallest nosing projection by more than three-eighths inch between two stories, including the nosing at the level of floors and landings. Beveling of nosings shall not exceed one-half inch.
2. Exceptions.
a. A nosing projection is not required where the tread depth is not less than 11 inches.
b. The opening between adjacent treads is not limited on stairs with a total rise of 30 inches or less.
(d) Exterior plastic composite stair treads. Plastic composite exterior stair treads shall comply with the provisions of this section and the requirements of ASTM D7032.
(5) Landings for stairways.
(a) General requirements. There shall be a floor or landing at the top and bottom of each stairway. A flight of stairs shall not have a vertical rise larger than 12 feet, three inches between floor levels or landings. The width of each landing shall not be less than the width of the stairway served. Every landing shall have a minimum dimension of 36 inches (914 mm), measured in the direction of travel.
(b) Exception. A floor or landing is not required at the top of an interior flight of stairs, including stairs in an enclosed garage, provided that a door does not swing over the stairs.
(6) Stairway walking surface. The walking surface of treads and landings of stairways shall be sloped not steeper than one unit vertical in 48 inches horizontal (2% slope).
(7) Handrails. Handrails shall be provided on not less than one side of each continuous run of treads or flight with four or more risers.
(a) Height.
1. General requirement. Handrail height, measured vertically from the sloped plane adjoining the tread nosing, or finish surface of ramp slope, shall be not less than 34 inches and not more than 38 inches.
2. Exceptions.
a. The use of a volute, turnout or starting easing shall be allowed over the lowest tread.
b. Where handrail fittings or bendings are used to provide continuous transition between flights, transitions at winder treads, the transition from handrail to guard, or used at the start of a flight, the handrail height at the fittings or bendings shall be permitted to exceed 38 inches.
(b) Continuity.
1. General requirements. Handrails for stairways shall be continuous for the full length of the flight, from a point directly above the top riser of the flight to a point directly above the lowest riser of the flight. Handrail ends shall be returned or shall terminate in newel posts or safety terminals. Handrails adjacent to a wall shall have a space of not less than one and one-half inches between the wall and the handrails.
2. Exceptions.
a. Handrails shall be permitted to be interrupted by a newel post at the turn.
b. The use of a volute, turnout, starting easing or starting newel shall be allowed over the lowest tread.
c. Two or more separate rails shall be considered continuous if the termination of the rails occurs within six inches of each other. If transitioning between a wall-mounted handrail and a guardrail/handrail, the wall-mounted rail shall return into the wall.
(c) Grip-size. Required handrails shall be of one of the following types or provide equivalent graspability.
1. Type I. Handrails with a circular cross section shall have an outside diameter of not less than one and one-quarter inches and not greater than two inches. If the handrail is not circular, it shall have a perimeter dimension of not less than four inches and not greater than six and one-quarter inches, with a cross section of dimension of not more than two and one-quarter inches. Edges shall have a radius of not less than 0.01 inch.
2. Type II.
a. General requirements. Handrails with a perimeter greater than six and one-quarter inches shall have a graspable finger recess area on both sides of the profile. The finger recess shall begin within a distance of three-quarters inch, measured vertically from the tallest portion of the profile, and achieve a depth of not less than five-sixteenths inch within seven-eighths inch below the widest portion of the profile. This required depth shall continue for not less than three-eighths inch to a level that is not less than one and three-quarters inches below the tallest portion of the profile. The width of the handrail above the recess shall be not less than one and one-quarter inches and not more than two and three-quarters inches. Edges shall have a radius of not less than 0.01 inch.
b. Exception. Exterior handrails (garages and areas exposed to the weather) shall not be more than three and one-half inches in cross-section dimension.
(d) Exterior plastic composite handrails. Plastic composite exterior handrails shall comply with the requirements of ASTM D7032.
(F) Special stairways.
(1) Spiral stairways. Spiral stairways are permitted, provided that the clear width at and below the handrail is not less than 26 inches, and the walkline radius is not greater than 24½ inches. Each tread shall have a depth of not less than six and three-quarters inches at the walkline. All treads shall be identical, and the rise shall be not more than nine and one-half inches. Headroom shall be not less than six feet, six inches.
(2) Bulkhead enclosure stairways. Stairways serving bulkhead enclosures, not part of the required building egress, providing access from the outside grade level to the basement, shall be exempt from the requirements where the height from the basement finished floor level to grade adjacent to the stairway is not more than eight feet, and the grade level opening to the stairway is covered by a bulkhead enclosure with hinged doors or other approved means.
(3) Bowed-tread stairways. Bowed-tread stairways are pemiitted, provided they are uniform in bowed-tread depth along the entire width of the tread, with not more than three-eighths-inch variance from greatest to smallest tread in the stairway flight. At no point shall the tread be less than nine inches with a nosing as above
(a) Standard stairway application. The bottom three treads in a standard straight run stairway application are permitted to bow, provided that, at no point along the width of the tread, they are less than nine inches, and each bowed tread is uniform with other bowed treads, with no more than three-eighths-inch variance from greatest to least. Nosing is required.
(b) Bowed tread circular stairways. Bowed treads in a circular stairway are permitted, provided they are uniform, as per winder treads measured at a point 12 inches from the side where the treads are narrower. At this walkline, bowed treads must be uniform with other circular stairway treads, with the greatest tread not to exceed the smallest by more than three-eighths inch. Nosing is required.
(c) Ship’s ladders. Ship’s ladders shall not be used as an element of a means of egress. Ship’s ladders shall be permitted, provided that a required means of egress stairway or ramp serves the same space at each adjoining level or where a means of egress is not required. The clear width at and below the handrails shall be not less than 20 inches.
1. Treads of ship’s ladders. Treads shall have a depth of not less than five inches. The tread shall be projected such that the total of the tread depth plus the nosing projection is not less than eight and one-half inches. The riser height shall be not more than nine and one-half inches.
2. Handrails of ship’s ladders. Handrails shall be provided on both sides of ship’s ladders. Handrail height shall be uniform, not less than 30 inches and not more than 34 inches.
(G) Ramps.
(1) Maximum slope.
(a) General requirements. Ramps serving the egress door shall have a slope of not more than one unit vertical in 12 units horizontal (8.3% slope). All other ramps shall have a maximum slope of one unit vertical in eight units horizontal (12.5% slope).
(b) Exception. Where it is technically infeasible to comply because of site constraints, ramps shall have a slope of not more than one unit vertical in eight units horizontal (12.5% slope).
(2) Landings required. There shall be a floor or landing at the top and bottom of each ramp, where doors open onto ramps, and where ramps change directions. The width of the landing perpendicular to the ramp slope shall be not less than 36 inches.
(3) Handrails required. Handrails shall be provided on not less than one side of ramps exceeding a slope of one unit vertical in 12 units horizontal (8.33% slope).
(a) Height. Handrail height, measured above the finished surface of the ramp slope, shall be not less than 34 inches and not more than 38 inches.
(b) Continuity. Where required on ramps, handrails shall be continuous for the full length of the ramp. Handrail ends shall be returned or shall terminate in newel posts or safety terminals. Handrails adjacent to a wall shall have a space of not less than one and one-half inches between the wall and the handrails.
(Ord. 2019-08-01, passed 9-9-19)