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Seattle |
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Municipal Code |
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Title 22. BUILDING AND CONSTRUCTION CODES |
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SubTitle II. Housing Code |
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Chapter 22.206. HABITABLE BUILDINGS |
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SubChapter IV. Minimum Fire and Safety Standards |
§ 22.206.130. Requirements
A.
Stairs and stairways
1.
All stairs, except stairs to inaccessible service areas, exterior stairs on grade and winding, circular, or spiral stairs, shall have a minimum run of 10 inches and a maximum rise of 7 3/4 inches and a minimum width of 36 inches from wall to wall. The rise and run may vary no more than 3/8 inch in any flight of stairs.
2.
All stairs, including exterior stairs on grade and winding, circular, and spiral stairs, shall be in good repair and shall be configured for safe use and travel.
3.
Every stairway having more than three risers, except stairs to inaccessible service areas, shall have at least one handrail of an easily grasped size and shape mounted not less than 34 inches or more than 38 inches above the tread nose. The ends of the handrail must either be returned or end in newel posts or safety terminals.
4.
A landing having minimum horizontal dimension of 36 inches shall be provided at each point of access to a stairway including the top and bottom of the stairway; provided, that stairs to an inaccessible service area need not have such a landing. A door that swings away from a stairway is considered to have created a landing in the area of its swing.
5.
Every required stairway shall have headroom clearance of not less than 6 feet 8 inches measured vertically from the nearest tread nose to the nearest soffit.
6.
Stairs or ladders within an individual dwelling unit used to gain access to intermediate floor areas of less than 400 square feet and not containing the primary bathroom or kitchen are exempt from the requirements of this subsection 22.206.130.A.
B.
Number of exits
1.
Occupied floors containing one or more housing unit(s) above the first floor or on any floor where the means of egress does not discharge within 4 feet, measured vertically, of adjacent ground level shall have access to not less than two unobstructed exits that meet the standards of Section 22.206.130; provided, that:
a.
Housing units may have a single exit if located on a second floor that has an occupant load of not more than ten persons or in a basement that has an occupant load of not more than ten persons; or
b.
A housing unit may have a single exit if the exit leads directly to a street, alley, other public right-of-way, or yard:
i.
At ground level, or
ii.
By way of an exterior stairway, or
iii.
By way of an enclosed stairway with a fire-resistant rating of one hour or more that serves only that housing unit and has no connection with any other floor below the floor of the housing unit being served or any other area not a part of the housing unit being served; or
c.
Housing units above the first floor or in a basement may have one exit if:
i.
An approved automatic fire-sprinkler system is provided for exit ways and common areas in the building, or
ii.
Built to the single exit requirements of the building code in effect when the building was constructed, altered, rehabilitated, or repaired.
2.
Floors other than those containing housing units shall meet the exit standards of the building code in effect when the building, structure, or premises was constructed or, if altered, rehabilitated, or repaired, shall meet the exit standards in effect when the floor was altered, rehabilitated, or repaired.
3.
If two exits are required, a fire escape that meets the standards of subsection 22.206.130.D may be used as one of the required exits.
C.
Stairway enclosures
1.
The standards for stairway enclosures are as follows:
a.
The walls of all portions of a stairway enclosure shall be at least one hour fire-resistive construction. Materials fastened to walls or floors of stairway enclosures shall comply with the 2015 Seattle Building Code Section 806; provided, that:
i.
Existing partitions forming part of a stairway enclosure shall be permitted in lieu of one-hour fire-resistive construction if they are constructed of lath and plaster that is not cracked, loose, or broken; or
ii.
Existing wainscoting and other decorative woodwork that was lawful at the time of installation is permitted if it is coated with an approved fire-retardant.
b.
Each opening onto a stairway enclosure shall be protected by a self-closing fire door and latching assembly providing fire-resistance equivalent to that provided by a solid wood door and assembly at least 1 3/4 inches thick.
2.
Stairway enclosures need not meet the above standards if:
a.
A lawfully installed automatic fire-extinguishing system is provided for all corridors, stairs, and common areas within the building;
b.
The stairway enclosure connects to only two floors and is not connected to corridors or stairways serving other floors; or
c.
The stairway enclosure is in a dwelling unit.
D.
Fire Escapes. An existing fire escape that is structurally sound may be used as one means of egress, provided that the pitch does not exceed 60 degrees, the width is not less than 18 inches, the run of the treads is not less than 4 inches, and the fire escape extends to the ground or is provided with counterbalanced stairs reaching to the ground. Access to a fire escape shall be from an opening having a minimum dimension of 29 inches in all directions when open. The sill of a fire escape window shall be no more than 30 inches above the floor and the exterior landing.
E.
Corridors, doors, and openings
1.
Corridors shall have a fire-resistance not less than that of wood lath and plaster that is not cracked, loose, or broken.
2.
Existing dead-end corridors longer than 30 feet that serve housing units shall be eliminated, unless an approved automatic sprinkler system is lawfully installed throughout the affected corridor, or unless approved smoke detectors are lawfully installed outside the door of each housing unit whose corridor exit door is located beyond the 30-foot limitation. The detectors may be self-contained or installed as part of the electrical system.
3.
Exit doors shall be self-closing, self-latching, and when serving an occupant load of 50 or more shall swing in the direction of exit travel. Exit doors from housing units that do not open directly into a stairway enclosure are exempt from these requirements if they were installed and are maintained in accordance with safety codes and ordinances in effect at the time of installation.
4.
Exit doors shall be openable from the inside without the use of a key or other special device, knowledge, or effort.
5.
All doors opening into a corridor, and not included as part of a stairway enclosure, shall be of solid wood at least 1 3/8 inches thick, or shall provide equivalent fire-resistance, except that doors opening directly to the outside, and doors in buildings where a lawfully installed automatic fire-sprinkler system is provided throughout all exit ways and other public rooms and areas within the building need not meet this standard.
6.
Transoms and openings other than doors, from corridors to rooms shall be fixed closed and shall be covered with a minimum of 5/8-inch gypsum Type "X" wallboard on both sides.
7.
Gravity-closing metal overhead or pocket doors in an exit path shall be removed or shall be permanently secured in the open position.
8.
All corridor walls, floors and ceilings shall be of one hour fire-resistive construction, or shall be repaired in accordance with codes and ordinances in effect at the time the corridor was constructed.
F.
Exit Signs. Every exit doorway or change of direction of a corridor shall be marked with a well-lighted exit sign or placard having green, legible letters at least 5 inches high. In the event of power supply failure, an emergency power system must illuminate the exit signs or placards.
G.
Enclosure of vertical openings
1.
Elevator shafts and other vertical openings shall be protected with construction as required for stairway enclosures in subsection 22.206.130.C.1 or by fixed wire-glass set in steel frames, or by assemblies that comply with Chapter 7 of the 2015 Seattle Building Code.
2.
Doors on vertical openings shall be of solid wood at least 1 3/8 inches thick or shall provide equivalent fire resistance.
H.
Separation of occupancies. Occupancy separations shall be provided as specified in Section 508 and Table 508.4 of the 2015 Seattle Building Code.
I.
Guardrails. A guardrail shall be provided whenever walking surfaces, including stairs, are 30 inches or more above adjacent surfaces, except in building service areas. Every guardrail shall be at least 36 inches in height unless it is an existing guardrail that was in compliance with the standards in effect at the time the guardrail was constructed, is in good condition, and is between 28 and 42 inches in height. Open guardrails shall have intermediate rails placed so that a sphere 4 inches or less in diameter cannot pass through.
J.
Emergency escape windows and doors
1.
Every room below the fourth story that was constructed for, converted to, or established for sleeping purposes after August 10, 1972, shall have at least one operable window or exterior door approved for emergency escape or rescue.
2.
Emergency escape windows and doors shall not open into an area without a means of escape. The emergency escape window or door shall be operable from the inside to provide a full clear opening without the use of separate tools. All emergency escape windows shall have a minimum net clear opening of 5.7 square feet. The minimum net clear openable height dimension shall be 24 inches. The minimum net clear openable width dimension shall be 20 inches. When a window is provided as a means of escape or rescue, it shall have a finished sill height not more than 44 inches above the floor. Emergency escape windows with sill heights greater than 44 inches above finished floor but 52 inches or less may have one step with a maximum height of eight inches and permanently fixed to the wall the full length of the openable portion of the window.
3.
Every room below the fourth story used for sleeping purposes that had on January 1, 1990, an operable window or door that met the requirements of Section 1204 of the 1985 Seattle Building Code adopted by Ordinances 113700 and 113701 , for emergency escape or rescue, regardless of the date of construction of the building, shall maintain that operable window or door as required by subsection 22.206.130.J.2.
K.
Bars, grilles, grates, or similar devices may be installed on emergency escape windows or doors, provided:
1.
Such devices are equipped with approved release mechanisms that are openable from the inside without the use of a key or special knowledge or effort; and
2.
The building is equipped with smoke detectors and carbon monoxide alarms as required by this Code.
L.
One- and two-family dwellings are exempt from the requirements of subsections 22.206.130.B through 22.206.130.H; provided, that for purposes of this subsection 22.206.130.L, no building containing residential and commercial uses or other similar mixed uses is considered a dwelling.