CHBC · California Historical Building Code
Emergency escape/rescue openings and related egress openings
The CHBC provides historically sensitive alternative rules for emergency escape and rescue openings (see §8‑503) while coordinating with CBC and Residential requirements.
Last reviewed: July 6, 2026
Overview
This area of the California Historical Building Code (CHBC) covers requirements and allowable alternatives for emergency escape and rescue openings—windows and doors used as secondary egress from sleeping rooms, basements and similar spaces in qualified historical buildings. The CHBC frames these provisions to preserve historic character while maintaining life safety; see the CHBC purpose and scope for means of egress and the principle that reasonable alternatives may be accepted where strict compliance would threaten historical significance (§8‑501 through §8‑502) .
The CHBC provides specific, often more permissive, dimensional tolerances for escape openings (for example, CHBC §8‑503 sets a minimum clear opening of 3.3 ft² and a minimum width or height of 18 inches) so long as openings are operable from the inside to provide a full clear opening . By contrast, the regular building and residential codes establish larger minimum net clear openings (see CBC provisions for emergency escape §1031 and Residential Code R319 with the 5.7 ft² / 24 in × 20 in baseline and related area‑well rules) — the CHBC explicitly works alongside those codes and accepts reasonable alternatives where appropriate .
Practical topics tied to these openings — area wells, ladders/steps, replacement windows, maintenance, and security devices — are addressed across the CHBC, CBC/Residential sections and the Fire Code. Required area‑well dimensions and ladder/step guidance and rules about bars/grilles that must be releasable from the inside (and often paired with required smoke alarms) are examples of compliance details to watch for in plan review and field work .
In this section
- What are the CHBC sill-height, clear opening and access requirements for egress openings leading to fire escapes?
- What are the minimum clear opening, dimensions and operability requirements for emergency escape/rescue windows and doors?
- Which basements and sleeping rooms must have an approved escape or rescue opening?
Code references
Grounded in the retrieved California Historical Building Code — click a citation to read the verbatim passage:
CHBC § 12-3 High relevance — show source text
Such bars, grills, grates or any similar devices shall be equipped with an approved exterior release device for use by the fire department only when required by the authority having jurisdiction.
Where security bars (burglar bars) are installed on emergency egress and rescue windows or doors, on or after July 1, 2000, such devices shall comply with California Building Standards Code, Part 12, Chapter 12-3 and other applicable provisions of Part 2.
Exception: Group R-1 occupancies provided with a monitored fire sprinkler system in accordance with Section 903.2.8 and designed in accordance with NFPA 13 may have openable windows permanently restricted to a maximum 4-inch (102 mm) open position.
1031.2.2 Maintenance. Fire escape stairways and balconies shall be kept clear and unobstructed at all times and shall be main- tained in good working order.
1031.2.3 Examination. Fire escape stairways and balconies shall be examined for structural adequacy and safety by a registered design professional or other person acceptable to the fire code official every 5 years. The examination shall determine whether the fire escape stairways and balconies can support the dead load plus a live load of not less than 100 pounds per square foot (4.78 kN/m). An inspection report shall be submitted to the fire code official after such examination.
1031.3 Emergency escape and rescue openings. Emergency escape and rescue openings shall comply with Sections 1031.3.1 through 1031.3.3.
1031.3.1 Minimum size. Emergency escape and rescue openings shall have a minimum net clear opening of 5.7 square feet (0.53 m [2] ).
Exception: The minimum net clear opening for grade-floor emergency escape and rescue openings shall be 5 square feet (0.46 m [2] ).
1031.3.2 Minimum dimensions. The minimum net clear opening height dimension shall be 24 inches (610 mm). The minimum net clear opening width dimension shall be 20 inches (508 mm). The net clear opening dimensions shall be the result of normal operation of the opening.
1031.3.3 Maximum height from floor. Emergency escape and rescue openings shall have the bottom of the clear opening not greater than 44 inches (1118 mm) measured from the floor.
1031.4 Emergency escape and rescue doors. Where a door is provided as the required emergency escape and rescue opening, it shall be a swinging door or a sliding door.
1031.5 Area wells. An emergency escape and rescue opening with the bottom of the clear opening below the adjacent grade shall be provided with an area well in accordance with Sections 1031.5.1 through 1031.5.3.
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1031.5.1 Minimum size. The minimum horizontal area of the area well shall be 9 square feet (0.84 m [2] ), with a horizontal projection and width of not less than 36 inches (914 mm). The area well shall allow the emergency escape and rescue opening to be fully opened.
Exception: The ladder or steps required by Section 1031.5.2 shall be permitted to encroach not more than 6 inches (152 mm) into the required dimensions of the area well.
CHBC § 1030.17.4 High relevance — show source text
1030.17.4 Guards at the end of aisles. A fascia or railing system complying with the guard requirements of Section 1015 shall be provided for the full width of the aisle where the foot of the aisle is more than 30 inches (762 mm) above the floor or grade below. The fascia or railing shall be not less than 36 inches (914 mm) high and shall provide not less than 42 inches (1067 mm) measured diagonally between the top of the rail and the nosing of the nearest tread.
SECTION 1031—EMERGENCY ESCAPE AND RESCUE
1031.1 General. Emergency escape and rescue openings shall comply with the requirements of this section.
1031.2 Where required. In addition to the means of egress required by this chapter, emergency escape and rescue openings shall be provided in Group R occupancies .
Basements and sleeping rooms below the fourth story above grade plane shall have not fewer than one emergency escape and rescue opening in accordance with this section. Where basements contain one or more sleeping rooms, an emergency escape and rescue opening shall be required in each sleeping room, but shall not be required in adjoining areas of the basement. Such open
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ings shall open directly into a public way or to a yard or court that opens to a public way, or to an egress balcony that leads to a public way.
Exceptions: 1. In Groups R-1 and R-2 occupancies constructed of Type I, Type IIA, Type IIIA or Type IV construction equipped throughout with an approved automatic sprinkler system in accordance with Section 903.3.1.1. 2. Group R-2.1 occupancies meeting the requirements for delayed egress in accordance with Section 1010.2.13 may have oper- able windows that are breakable in sleeping rooms permanently restricted to a maximum of 4-inch open position. 3 . Basements with a ceiling height of less than 80 inches (2032 mm) shall not be required to have emergency escape and rescue openings. 4 . Emergency escape and rescue openings are not required from basements or sleeping rooms that have an exit door or exit access door that opens directly into a public way or to a yard, court or exterior egress balcony that leads to a public
way. 5 . Basements without habitable spaces and having not more than 200 square feet (18.6 m [2] ) in floor area shall not be required to have emergency escape and rescue openings. 6 . Storm shelters are not required to comply with this section where the shelter is constructed in accordance with ICC 500. 7 . Within individual dwelling and sleeping units in Groups R-2 and R-3, where the building is equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.1, 903.3.1.2 or 903.3.1.3, sleeping rooms in basements shall not be required to have emergency escape and rescue openings provided that the basement has one of the following: 7.1. One means of egress and one emergency escape and rescue opening. 7.2. Two means of egress. 8. In Group R-2.2 occupancies a certified fire escape is acceptable as a secondary means of egress for existing buildings for this section of the code.
CHBC § 18.6 High relevance — show source text
R319.1 Emergency escape and rescue opening required. Basements, habitable attics, the room to which a sleeping loft is open, and every sleeping room shall have not less than one operable emergency escape and rescue opening. Where basements contain one or more sleeping rooms, an emergency escape and rescue opening shall be required in each sleeping room. Emergency escape and rescue openings shall open directly into a public way, or to a yard or court that opens to a public way.
Exceptions [SFM]: 1. Basements with a ceiling height of less than 80 inches (2032 mm) shall not be required to have emergency escape and rescue openings. 2. Emergency escape and rescue openings are not required from basements or sleeping rooms that have an exit door or exit access door that opens directly into a public way or to a yard, court or exterior egress balcony that opens to a public way. 3. Basements without habitable spaces and having not more than 200 square feet (18.6 m [2] ) in floor area shall not be required to have emergency escape and rescue openings. 4. Storm shelters are not required to comply with this section where the shelter is constructed in accordance with ICC 500. 5. Where the dwelling unit or townhouse unit is equipped with an automatic sprinkler system installed in accordance with Section R309, sleeping rooms in basements shall not be required to have emergency escape and rescue openings provided that the basement has one of the following: 5.1. One means of egress complying with Section R318 and one emergency escape and rescue opening. 5.2. Two means of egress complying with Section R318.
R319.1.1 Operational constraints and opening control devices. Emergency escape and rescue openings shall be maintained free of any obstructions other than those allowed by this section and shall be operational from the inside of the room without the use of keys, tools or special knowledge. Window opening control devices and fall prevention devices complying with ASTM F2090 shall be permitted for use on windows serving as a required emergency escape and rescue opening and shall be not more than 70 inches (178 cm) above the finished floor. The release mechanism shall be maintained operable at all times.
Such bars, grills, grates or any similar devices shall be equipped with an approved exterior release device for use by the fire department only when required by the authority having jurisdiction.
Where security bars (burglar bars) are installed on emergency egress and rescue windows or doors, on or after July 1, 2000, such devices shall comply with California Building Standards Code, Part 12, Chapter 12-3 and other applicable provisions of this code.
R319.2 Emergency escape and rescue openings. Emergency escape and rescue openings shall have minimum dimensions in accordance with Sections R319.2.1 through R319.2.4.
R319.2.1 Minimum size. Emergency escape and rescue openings shall have a net clear opening of not less than 5.7 square feet (0.530 m [2] ).
Exception: The minimum net clear opening for grade-floor emergency escape and rescue openings shall be 5 square feet (0.465 m [2] ).
R319.2.2 Minimum dimensions. The minimum net clear opening height dimension shall be 24 inches (610 mm). The minimum net clear opening width dimension shall be 20 inches (508 mm). The net clear opening dimensions shall be the result of normal operation of the opening.
CHBC § 8-5 High relevance — show source text
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8-5 MEANS OF EGRESS
SECTION 8-501 — PURPOSE, INTENT AND SCOPE
8-501.1 Purpose. The purpose of this chapter is to establish minimum means of egress regulations for qualified historical buildings or properties. The CHBC requires enforcing agencies to accept reasonably equivalent alternatives to the means of egress requirements in the regular code.
8-501.2 Intent. The intent of these regulations is to provide an adequate means of egress.
8-501.3 Scope. Every qualified historical building or portion thereof shall be provided with exits as required by the CHBC when required by the provisions of Section 8-102.
SECTION 8-502 — GENERAL
8-502.1 General. The enforcing agency shall grant reasonable exceptions to the specific provisions of applicable egress regulations where such exceptions will not adversely affect life safety.
8-502.2. Existing door openings and corridor widths of less than dimensions required by regular code shall be permitted where there is sufficient width and height for the occupants to pass through the opening or traverse the exit.
8-502.3 Stairs. Existing stairs having risers and treads or width at variance with the regular code are allowed if determined by the enforcing agency to not constitute a distinct hazard. Handrails with nonconforming grip size or extensions are allowed if determined by the enforcing agency to not constitute a distinct hazard.
8-502.4 Main entry doors. The front or main entry doors need not be rehung to swing in the direction of exit travel, provided other means or conditions of exiting, as necessary to serve the total occupant load, are provided.
8-502.5 Existing fire escapes. Existing previously approved fire escapes and fire escape ladders shall be acceptable as one of the required means of egress, provided they extend to the ground and are easily negotiated, adequately signed and in good working order. Access shall be by an opening having a minimum width of 29 inches (737 mm) when open with a sill no more than 30 inches (762 mm) above the adjacent floor, landing or approved step.
8-502.6 New fire escapes and fire escape ladders. New fire escapes and fire escape ladders which comply with this section shall be acceptable as one of the required means of egress. New fire escapes and new fire escape ladders shall comply with the following:
- Access from a corridor shall not be through an intervening room.
- All openings within 10 feet (3048 mm) shall be protected by three-fourths-hour fire assemblies. When located within a recess or vestibule, adjacent enclosure walls shall be of not less than one-hour fire-resistive construction.
- Egress from the building shall be by a clear opening having a minimum dimension of not less than 29 inches (737 mm). Such openings shall be openable from the inside without the use of a key or special knowledge or effort. The sill of an opening giving access shall not be more than 30 inches (737 mm) above the floor, step or landing of the building or balcony.
- Fire escape stairways and balconies shall support the dead load plus a live load of not less than 100 pounds per square foot (4.79 kN/m [2] ) and shall be provided with a top and intermediate handrail on each side. The pitch of the stairway shall not exceed 72 degrees with a minimum width of 18 inches (457 mm).
CHBC § 3.1. High relevance — show source text
Exception: In areas required for bed movement, equipment shall be permitted in the required width where all of the following provisions are met:
- The equipment is low hazard and wheeled.
- The equipment does not reduce the effective clear width for the means of egress to less than 5 feet (1525 mm).
- The equipment is limited to: 3.1. Equipment and carts in use. 3.2. Medical emergency equipment.
3.3. Infection control carts.
3.4. Patient lift and transportation equipment. 4. Medical emergency equipment and patient lift and transportation equipment, when not in use, are required to be located on one side of the corridor.
- The equipment is limited in number to not more than one per patient sleeping room or patient care room within each smoke compartment.
[BE] 1032.4 Exit signs. Exit signs shall be installed and maintained in accordance with the building code that was in effect at the time of construction and the applicable provisions in Section 1104. Decorations, furnishings, equipment or adjacent signage that impairs the visibility of exit signs, creates confusion or prevents identification of the exit shall not be allowed.
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1032.5 Nonexit identification. Where a door is adjacent to, constructed similar to and can be confused with a means of egress door, that door shall be identified with an approved sign that identifies the room name or use of the room.
1032.6 Finishes, furnishings and decorations. Means of egress doors shall be maintained in such a manner as to be distinguishable from the adjacent construction and finishes such that the doors are easily recognizable as doors. Furnishings, decorations or other objects shall not be placed so as to obstruct exits, access thereto, egress therefrom, or visibility thereof. Hangings and draperies shall not be placed over exit doors or otherwise be located to conceal or obstruct an exit. Mirrors shall not be placed on exit doors. Mirrors shall not be placed in or adjacent to any exit in such a manner as to confuse the direction of egress.
1032.7 Emergency escape and rescue openings. Required emergency escape and rescue openings shall be maintained in accordance with the code in effect at the time of construction, and both of the following:
Required emergency escape and rescue openings shall be operational from the inside of the room without the use of keys or tools.
Bars, grilles, grates or similar devices are permitted to be placed over emergency escape and rescue openings provided that the minimum net clear opening size complies with the code that was in effect at the time of construction and the unit is equipped with smoke alarms installed in accordance with Section 907.2.11. Such devices shall be releasable or removable from the inside without the use of a key, tool or force greater than that which is required for normal operation of the emergency escape and rescue opening.
1032.8 Inspection, testing and maintenance. The inspection, testing and maintenance for two-way communication systems shall be in accordance with this code and NFPA 72, and shall be conducted not less than annually or more frequently where required by the fire code official.
1032.8.1 Records. Records of inspections, testing and maintenance shall be maintained on site in a location approved by the fire code official.
CHBC § 18.6 High relevance — show source text
Basements with a ceiling height of less than 80 inches (2032 mm) shall not be required to have emergency escape and rescue openings. 4 . Emergency escape and rescue openings are not required from basements or sleeping rooms that have an exit door or exit access door that opens directly into a public way or to a yard, court or exterior egress balcony that leads to a public
way. 5 . Basements without habitable spaces and having not more than 200 square feet (18.6 m [2] ) in floor area shall not be required to have emergency escape and rescue openings. 6 . Storm shelters are not required to comply with this section where the shelter is constructed in accordance with ICC 500. 7 . Within individual dwelling and sleeping units in Groups R-2 and R-3, where the building is equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.1, 903.3.1.2 or 903.3.1.3, sleeping rooms in basements shall not be required to have emergency escape and rescue openings provided that the basement has one of the following: 7.1. One means of egress and one emergency escape and rescue opening. 7.2. Two means of egress. 8. In Group R-2.2 occupancies a certified fire escape is acceptable as a secondary means of egress for existing buildings for this section of the code.
1031.2.1 Operational constraints and opening control devices. Emergency escape and rescue openings and any exit doors shall be maintained free of any obstructions other than those allowed by this section and shall be operational from inside the room without the use of keys or tools. Window-opening control devices complying with ASTM F2090 shall be permitted for use on windows serving as a required emergency escape and rescue opening. The release mechanism shall be maintained operable at all times.
Such bars, grills, grates or any similar devices shall be equipped with an approved exterior release device for use by the fire department only when required by the authority having jurisdiction.
Where security bars (burglar bars) are installed on emergency egress and rescue windows or doors, on or after July 1, 2000, such devices shall comply with California Building Standards Code, Part 12, Chapter 12-3 and other applicable provisions of Part 2.
Exception: Group R-1 occupancies provided with a monitored fire sprinkler system in accordance with Section 903.2.8 and designed in accordance with NFPA 13 may have openable windows permanently restricted to a maximum 4-inch (102 mm) open position.
1031.2.2 Maintenance. Fire escape stairways and balconies shall be kept clear and unobstructed at all times and shall be main- tained in good working order.
1031.2.3 Examination. Fire escape stairways and balconies shall be examined for structural adequacy and safety by a registered design professional or other person acceptable to the fire code official every 5 years. The examination shall determine whether the fire escape stairways and balconies can support the dead load plus a live load of not less than 100 pounds per square foot (4.78 kN/m). An inspection report shall be submitted to the fire code official after such examination.
1031.3 Emergency escape and rescue openings. Emergency escape and rescue openings shall comply with Sections 1031.3.1 through 1031.3.3.
CHBC § 8-503 High relevance — show source text
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SECTION 8-503 — ESCAPE OR RESCUE WINDOWS AND DOORS
Basements in dwelling units and every sleeping room below the fourth floor shall have at least one openable window or door approved for emergency escape which shall open directly into a public street, public way, yard or exit court. Escape or rescue windows or doors shall have a minimum clear area of 3.3 square feet (0.31 m [2] ) and a minimum width or height dimension of 18 inches (457 mm) and be operable from the inside to provide a full, clear opening without the use of special tools.
SECTION 8-504 — RAILINGS AND GUARDRAILS
The height of railings and guard railings and the spacing of balusters may continue in their historical height and spacing unless a distinct hazard has been identified or created by a change in use or occupancy.
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8-6 ACCESSIBILITY
SECTION 8-601 — PURPOSE, INTENT AND SCOPE
8-601.1 Purpose. The purpose of the CHBC is to provide alternative regulations to facilitate access and use by persons with disabilities to and throughout facilities designated as qualified historical buildings or properties. These regulations require enforcing agencies to accept alternatives to regular code when dealing with qualified historical buildings or properties.
8-601.2 Intent. The intent of this chapter is to preserve the integrity of qualified historical buildings and properties while providing access to and use by persons with disabilities.
8-601.3 Scope. The CHBC shall apply to every qualified historical building or property that is required to provide access to persons with disabilities.
- Provisions of this chapter do not apply to new construction or reconstruction/replicas of historical buildings.
- Where provisions of this chapter apply to alteration of qualified historical buildings or properties, alteration is defined in California Building Code (CBC), Chapter 2.
8-601.4 General application. The provisions in the CHBC apply to local, state and federal governments (Title II entities); alteration of commercial facilities and places of public accommodation (Title III entities); and barrier removal in commercial facilities and places of public accommodation (Title III entities). Except as noted in this chapter.
SECTION 8-602 — BASIC PROVISIONS
8-602.1 Regular code. The regular code for access for people with disabilities (Title 24, Part 2, Vol. 1, Chapter 11B) shall be applied to qualified historical buildings or properties unless strict compliance with the regular code will threaten or destroy the historical significance or character-defining features of the building or property.
8-602.2 Alternative provisions. If the historical significance or character-defining features are threatened, alternative provisions for access may be applied pursuant to this chapter, provided the following conditions are met:
- These provisions shall be applied only on an item-by-item or a case-by-case basis.
- Documentation is provided, including meeting minutes or letters, stating the reasons for the application of the alternative provisions. Such documentation shall be retained in the permanent file of the enforcing agency.
SECTION 8-603 — ALTERNATIVES
CHBC § 3-64 High relevance — show source text
R318.8 Ramps. Where required by this code or provided, ramps shall comply with this section.
Exception: Ramps not within or serving a building, porch or deck.
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BUILDING PLANNING
R318.8.1 Maximum slope. Ramps serving the egress door required by Section R318.2 shall have a slope of not more than 1 unit vertical in 12 units horizontal (8.3-percent slope).
Other ramps shall have a slope of not more than 1 unit vertical in 8 units horizontal (12.5 percent).
Exception: Where it is technically infeasible to comply because of site constraints, ramps shall have a slope of not more than 1 unit vertical in 8 units horizontal (12.5 percent).
R318.8.2 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 the width of the ramp. The depth of the landing in the direction of the ramp slope shall be not less than 36 inches (914 mm).
R318.8.3 Handrails required. Handrails shall be provided on not less than one side of ramps exceeding a slope of 1 unit vertical in 12 units horizontal (8.33-percent slope) and shall comply with Section R320.
SECTION R319—EMERGENCY ESCAPE AND RESCUE OPENINGS
R319.1 Emergency escape and rescue opening required. Basements, habitable attics, the room to which a sleeping loft is open, and every sleeping room shall have not less than one operable emergency escape and rescue opening. Where basements contain one or more sleeping rooms, an emergency escape and rescue opening shall be required in each sleeping room. Emergency escape and rescue openings shall open directly into a public way, or to a yard or court that opens to a public way.
Exceptions [SFM]: 1. Basements with a ceiling height of less than 80 inches (2032 mm) shall not be required to have emergency escape and rescue openings. 2. Emergency escape and rescue openings are not required from basements or sleeping rooms that have an exit door or exit access door that opens directly into a public way or to a yard, court or exterior egress balcony that opens to a public way. 3. Basements without habitable spaces and having not more than 200 square feet (18.6 m [2] ) in floor area shall not be required to have emergency escape and rescue openings. 4. Storm shelters are not required to comply with this section where the shelter is constructed in accordance with ICC 500. 5. Where the dwelling unit or townhouse unit is equipped with an automatic sprinkler system installed in accordance with Section R309, sleeping rooms in basements shall not be required to have emergency escape and rescue openings provided that the basement has one of the following: 5.1. One means of egress complying with Section R318 and one emergency escape and rescue opening. 5.2. Two means of egress complying with Section R318.
CHBC § 10-61 High relevance — show source text
- Group R-3 and R-4 occupancies.
Basements and sleeping rooms below the fourth story above grade plane shall have not fewer than one emergency escape and rescue opening in accordance with this section. Where basements contain one or more sleeping rooms, an emergency escape and rescue opening shall be required in each sleeping room, but shall not be required in adjoining areas of the basement. Such open
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ings shall open directly into a public way or to a yard or court that opens to a public way, or to an egress balcony that leads to a public way.
Exceptions: 1. In Groups R-1 and R-2 occupancies constructed of Type I, Type IIA, Type IIIA or Type IV construction equipped throughout with an approved automatic sprinkler system in accordance with Section 903.3.1.1. 2. Group R-2.1 occupancies meeting the requirements for delayed egress in accordance with Section 1010.2.13 may have oper- able windows that are breakable in sleeping rooms permanently restricted to a maximum of 4-inch open position. 3. Basements with a ceiling height of less than 80 inches (2032 mm) shall not be required to have emergency escape and rescue openings. 4. Emergency escape and rescue openings are not required from basements or sleeping rooms that have an exit door or exit access door that opens directly into a public way or to a yard, court or exterior egress balcony that leads to a public
way. 5. Basements without habitable spaces and having not more than 200 square feet (18.6 m [2] ) in floor area shall not be required to have emergency escape and rescue openings. 6. Storm shelters are not required to comply with this section where the shelter is constructed in accordance with ICC 500. 7. Within individual dwelling and sleeping units in Groups R-2 and R-3, where the building is equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.1, 903.3.1.2 or 903.3.1.3, sleeping rooms in basements shall not be required to have emergency escape and rescue openings provided that the basement has one of the following: 7.1. One means of egress and one emergency escape and rescue opening. 7.2. Two means of egress. 8. In Group R-2.2 occupancies a certified fire escape is acceptable as a secondary means of egress of existing buildings for this section of the code.
[BE] 1031.2.1 Operational constraints and opening control devices. Emergency escape and rescue openings and any exit doors shall be maintained free of any obstructions other than those allowed by this section and shall be operational from inside the room without the use of keys or tools. Window-opening control devices complying with ASTM F2090 shall be permitted for use on windows serving as a required emergency escape and rescue opening. The release mechanism shall be maintained operable at all times.
Such bars, grills, grates or any similar devices shall be equipped with an approved exterior release device for use by the fire department only when required by the authority having jurisdiction.
CHBC § 1031.3 High relevance — show source text
(a) Where the California Building Code requires openable burglar bars for emergency escape or rescue, or
(b) On mobile homes, manufactured homes or multi-unit manufactured housing unless at least one window or door to the exterior in each bedroom is openable for emergency escape or rescue.
[BE] 1031.3 Emergency escape and rescue openings. Emergency escape and rescue openings shall comply with Sections 1031.3.1 through 1031.3.3.
[BE] 1031.3.1 Minimum size. Emergency escape and rescue openings shall have a minimum net clear opening of 5.7 square feet (0.53 m [2] ). Exception: The minimum net clear opening for grade-floor emergency escape and rescue openings shall be 5 square feet (0.46 m [2] ).
[BE] 1031.3.2 Minimum dimensions. The minimum net clear opening height dimension shall be 24 inches (610 mm). The minimum net clear opening width dimension shall be 20 inches (508 mm). The net clear opening dimensions shall be the result of normal operation of the opening.
[BE] 1031.3.3 Maximum height from floor. Emergency escape and rescue openings shall have the bottom of the clear opening not greater than 44 inches (1118 mm) measured from the floor.
[BE] 1031.4 Emergency escape and rescue doors. Where a door is provided as the required emergency escape and rescue opening, it shall be a swinging door or a sliding door.
[BE] 1031.5 Area wells. An emergency escape and rescue opening with the bottom of the clear opening below the adjacent grade shall be provided with an area well in accordance with Sections 1031.5.1 through 1031.5.3.
[BE] 1031.5.1 Minimum size. The minimum horizontal area of the area well shall be 9 square feet (0.84 m [2] ), with a horizontal projection and width of not less than 36 inches (914 mm). The area well shall allow the emergency escape and rescue opening to be fully opened.
Exception: The ladder or steps required by Section 1031.5.2 shall be permitted to encroach not more than 6 inches (152 mm) into the required dimensions of the area well.
[BE] 1031.5.2 Ladders or steps. Area wells with a vertical depth of more than 44 inches (1118 mm) shall be equipped with an approved permanently affixed ladder or steps. The ladder or steps shall not be obstructed by the emergency escape and rescue opening when the window or door is in the open position. Ladders or steps required by this section shall not be required to comply with Section 1011.
[BE] 1031.5.2.1 Ladders. Ladders or rungs shall have an inside width of at least 12 inches (305 mm), shall project at least 3 inches (76 mm) from the wall and shall be spaced not more than 18 inches (457 mm) on center (o.c.) vertically for the full height of the area well.
[BE] 1031.5.2.2 Steps. Steps shall have an inside width of not less than 12 inches (305 mm), shall have treads greater than 5 inches (127 mm) in depth and a riser height not greater than 18 inches (457 mm) for the full height of the area well.
CHBC § 33.3 High relevance — show source text
Stairway openings in such balconies shall not be less than 22 inches by 44 inches (559 by 1118 mm). The balustrade of each balcony shall not be less than 36 inches (914 mm) high with not more than 9 inches (287 mm) between balusters. 6. Fire escapes shall extend to the roof or provide an approved gooseneck ladder between the top floor landing and the roof when serving buildings four or more stories in height having roofs with less than 4 units vertical in 12 units horizontal (33.3 percent slope). Fire escape ladders shall be designed and connected to the building to withstand a horizontal force of 100 pounds (445 N) placed anywhere on the rung. All ladders shall be at least 15 inches (381 mm) wide, located within 12 inches (305 mm) of the building. Ladder rungs shall be [3] / 4 inch (19.1 mm) in diameter and shall be located 12 inches (305 mm) on center. Openings for roof access ladders through cornices and similar projections shall have minimum dimensions of 30 inches by 33 inches (762 by 838 mm). The length of fire escapes and exit ladder devices shall be limited to that approved by the building official based on products listed by a recognized testing laboratory. 7. The lowest balcony shall not be more than 18 feet (5486 mm) from the ground. Fire escapes shall extend to the ground or be provided with counterbalanced stairs reaching to the ground. 8. Fire escapes shall not take the place of stairways required by the codes under which the building was constructed. 9. Fire escapes shall be kept clear and unobstructed at all times and maintained in good working order.
2025 CALIFORNIA HISTORICAL BUILDING CODE 9
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
MEANS OF EGRESS
SECTION 8-503 — ESCAPE OR RESCUE WINDOWS AND DOORS
Basements in dwelling units and every sleeping room below the fourth floor shall have at least one openable window or door approved for emergency escape which shall open directly into a public street, public way, yard or exit court. Escape or rescue windows or doors shall have a minimum clear area of 3.3 square feet (0.31 m [2] ) and a minimum width or height dimension of 18 inches (457 mm) and be operable from the inside to provide a full, clear opening without the use of special tools.
SECTION 8-504 — RAILINGS AND GUARDRAILS
The height of railings and guard railings and the spacing of balusters may continue in their historical height and spacing unless a distinct hazard has been identified or created by a change in use or occupancy.
10 2025 CALIFORNIA HISTORICAL BUILDING CODE
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
8-6 ACCESSIBILITY
SECTION 8-601 — PURPOSE, INTENT AND SCOPE
8-601.1 Purpose. The purpose of the CHBC is to provide alternative regulations to facilitate access and use by persons with disabilities to and throughout facilities designated as qualified historical buildings or properties. These regulations require enforcing agencies to accept alternatives to regular code when dealing with qualified historical buildings or properties.
Frequently asked questions
What minimum size does the CHBC require for escape or rescue windows and doors?
CHBC §8‑503 requires a minimum clear area of 3.3 square feet and a minimum width or height of 18 inches; the opening must be operable from the inside to provide a full clear opening without special tools .
How does the CHBC relate to the regular building and residential code requirements?
The CHBC provides alternative, historically sensitive provisions and permits authorities to accept reasonably equivalent alternatives where strict compliance would threaten historic character (§8‑501/§8‑502) while remaining tied to the regular code for other aspects; the regular CBC and the Residential Code establish larger baseline escape‑opening sizes (CBC §1031 and R319: generally 5.7 ft² net clear, 24 in minimum height, 20 in minimum width, and max sill height 44 in) that inform but do not automatically override CHBC alternatives .
Are burglar bars or grilles allowed over required escape openings?
Bars, grilles or similar devices may be used if they comply with releasability and operational rules (must be releasable or removable from the inside without keys, tools or excessive force, and release mechanisms must be maintained); some provisions also require smoke alarms and/or exterior release devices for fire department access — see the Residential and Fire Code provisions and Title 19 installer/labeling requirements for details .
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