CHBC · California Historical Building Code

When does secondary work (outside footprints) fall under the CHBC?

Q: What if applying the regular code would be safer but would alter historic character?

The CHBC requires a balance: do not unduly restrict permitted use under § 8-1002.4 , but safety is important. Use CHBC’s performance-based alternatives and coordinate with the enforcing agency to find an acceptable solution.

If work outside your historic building (for example, trenching, grading, paving or new utilities) affects the historic site, landscape, or other features beyond the building’s footprint, the CHBC applies to those impacts (see **§ 8-1002.2**). The CHBC requires context-sensitive, performance-based alternatives and prevents code application that would *unduly restrict* the building’s permitted use (**§ 8-1002.4**).

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Last reviewed: July 6, 2026

What the code requires — 2–4 sentences

The CHBC says that when the application of the regular code would impact the associated features of a qualified historical property beyond its footprint by work performed secondarily, those impacts are governed by the CHBC rather than only by the regular code (§ 8-1002.2). § 8-1002.4 adds that application of any code or standard must not unduly restrict the use of a qualified historical building or property. § 8-1002.2 and § 8-1002.4 are the controlling rules for secondary (outside-footprint) work.

If regular-code work done outside a historic building affects the property's historic site, landscape or other associated features, treat those impacts under the CHBC (not just the regular code).

Requirements in detail

Key defined terms (first mention bolded):

Qualified historical building — a building or property that meets the CHBC qualifications.
Associated features — site, landscape, objects and features beyond the building proper (e.g., circulation, grading, historic paving, gardens, site structures). See the chapter scope.
Work performed secondarily — the CHBC phrase indicating actions outside the building that nevertheless impact associated historic features; the CHBC uses the phrase but does not provide a separate statutory definition in § 8-1002.2.
Footprint — the area beneath and immediately occupied by the building; impacts beyond that area are “beyond their footprints” in the CHBC language.

How to decide whether the CHBC applies

Use the decision dimensions below. Each cell tells you the factor to check and the CHBC provision that governs that factor.

Decision dimension	Decision threshold / values that trigger CHBC coverage	Code Reference
Location of work	Work that impacts associated features beyond the building footprint → CHBC applies	§ 8-1002.2
Type of impact	Secondary impacts (e.g., grading, utilities, paving, drainage, site structures) that affect historic features → CHBC applies	§ 8-1002.2; scope of associated features § 8-1001.2
Purpose of regulation	If applying regular code would change how the historic site/property is used or would unduly restrict its permitted use → limit application per CHBC	§ 8-1002.4
Issues covered	All code compliance matters that affect the purpose of Chapter 8-10 (site relations, landscape, objects) → CHBC guidance used	§ 8-1002.3 and § 8-1001.2
Relationship to enforcing agency action	Enforcing agencies must use CHBC for repairs/alterations that affect associated features beyond footprints	§ 8-1002.1 and chapter intent (§ 8-1001.1)

Practical steps an applicant or plan reviewer should take

Identify whether the property is a qualified historical building/property (CHBC jurisdiction). If not qualified, CHBC does not apply.
Map the footprint and the associated features (landscape, site circulation, outbuildings, paving, grading, drainage, water features, lighting, utility placement) per the CHBC scope. § 8-1001.2 lists examples of associated features.
Ask: Will the proposed work (even if outside the building) change, damage, or require changes to those associated features? If yes, treat impacts under the CHBC per § 8-1002.2.
If applying the regular code to the secondary work would unduly restrict the property’s use, the enforcing agency must consider CHBC alternatives per § 8-1002.4.

What the CHBC does (and does not) require here

It requires that secondary impacts beyond the footprint be considered under the CHBC (performance-oriented, context-sensitive alternatives are expected). § 8-1002.2 and the chapter intent explain this.
It does not supply a prescriptive list of every permitted or prohibited secondary action (the CHBC is performance-based). If a specific technical requirement is needed, consult the applicable CHBC chapters and coordinate with the enforcing agency.

Exceptions & special cases

The CHBC will not be used to unduly restrict lawful use or permitted actions where chapter 8-3 allowances apply; § 8-1002.4 requires balancing code application so the historic property’s use is not improperly limited.
New construction or reconstruction replicas are generally not covered by CHBC in some chapters; verify qualification and chapter scope before assuming coverage. See the CHBC intent and definitions for qualified structures.
If the work is completely unrelated to the historic site features (no effect on associated features beyond ordinary disturbance) the CHBC trigger in § 8-1002.2 may not apply — but you must document that lack of impact. The CHBC does not define “secondary” in § 8-1002.2, so documenting the causal link between the outside work and the associated feature impact is essential.

Common mistakes

Assuming any work outside the wall line is automatically outside CHBC jurisdiction — wrong. The CHBC applies when that outside work impacts associated features beyond the footprint (see § 8-1002.2).
Failing to map and document associated features (historic landscape, paving, grading, drainage) before permitting — this makes it harder to show whether CHBC applies. The CHBC scope (examples) is in § 8-1001.2.
Treating § 8-1002.4 as a blanket way to avoid regular-code safety requirements — it requires avoiding undue restriction of use, not compromising life-safety. Evaluate alternatives with the enforcing agency.

Worked example

Scenario: A historic mission building sits on a ¼-acre parcel with original stone paving, historic cistern, and historic landscape beds that extend 10 feet beyond the building walls. A project proposes to extend an underground sanitary sewer by 25 feet from the street, trenching through the historic paving and filling adjacent historic planting beds.

Is the property a qualified historical building/property? If yes, CHBC is potentially applicable.
Does the trenching impact associated features beyond the footprint (stone paving, cistern, landscape beds)? Yes — the trench would physically alter those features. Result: The impacts are covered by the CHBC under § 8-1002.2.
Next steps under CHBC workflow: document the historic features, coordinate with the enforcing agency for CHBC performance-based alternatives (e.g., microtrenching, directional bore, reinstatement of historic paving patterns), and ensure solutions do not unduly restrict use per § 8-1002.4.

Related provisions

§ 8-1001.2 — Scope: examples of associated historical features (site layout, landscape elements, functional elements).
§ 8-1002.1 — CHBC applies to all sites/districts associated with qualified historical buildings.
§ 8-1002.3 — Apply this chapter to all issues affecting its purpose.
§ 8-1003 — Site relations: context-sensitive solutions when work is performed secondarily and impacts associated features.
CHBC intent and definitions (see early CHBC chapters) — for qualification and treatment concepts.

Code references

Grounded in the retrieved California Historical Building Code — click a citation to read the verbatim passage:

CHBC § 8-1002.1 High relevance — show source text

8-1002.1 The CHBC shall apply to all sites and districts and their features associated with qualified historical buildings or qualified historical districts as outlined in 8-1001.2 Scope.

8-1002.2 Where the application of regular code may impact the associated features of qualified historical properties beyond their footprints, by work performed secondarily, those impacts shall also be covered by the CHBC.

8-1002.3 This chapter shall be applied for all issues regarding code compliance or other standard or regulation as they affect the purpose of this chapter.

8-1002.4 The application of any code or building standard shall not unduly restrict the use of a qualified historical building or property that is otherwise permitted pursuant to Chapter 8-3 and the intent of the State Historical Building Code, Section 18956.

SECTION 8-1003 — SITE RELATIONS

The relationship between a building or property and its site, or the associated features of a district (including qualified historical landscape), site, objects and their features are critical components that may be one of the criteria for these buildings and properties to be qualified under the CHBC. The CHBC recognizes the importance of these relationships. This chapter shall be used to provide context sensitive solutions for treatment of qualified historical buildings, properties, district or their associated historical features, or when work to be performed secondarily impacts the associated historical features of a qualified historical building or property.

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APPENDIX A	Col2	Col3	Col4
CHAPTER 8-6—TABLE 1—PROVISION APPLICABILITY	CHAPTER 8-6—TABLE 1—PROVISION APPLICABILITY	CHAPTER 8-6—TABLE 1—PROVISION APPLICABILITY	CHAPTER 8-6—TABLE 1—PROVISION APPLICABILITY
	Title II Public Entities	Title III Private Entities	Title III Barrier Removal
SECTION 8-601 PURPOSE, INTENT, 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 quali- fied 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. 1.Provisions of this chapter do not apply to new construction or reconstruction/replicas of historical buildings. 2. 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.

CHBC § 8-1001.1 High relevance — show source text
8-1001.1 Purpose. The purpose of this chapter is to provide regulations for the preservation, rehabilitation, restoration and reconstruction of associated historical features of qualified historical buildings, properties or districts (as defined in Chapter 8-2), and for which Chapters 8-3 through 8-9 of the CHBC may not apply.

8-1001.2 Scope. This chapter applies to the associated historical features of qualified historical buildings or properties such as historical districts that are beyond the buildings themselves which include, but are not limited to, natural features and designed site and landscape plans with natural and man-made landscape elements that support their function and aesthetics. This may include, but will not be limited to:
1. Site plan layout configurations and relationships (pedestrian, equestrian and vehicular site circulation, topographical grades and drainage, and use areas).
2. Landscape elements (plant materials, site structures other than the qualified historical building, bridges and their associated structures, lighting, water features, art ornamentation, and pedestrian, equestrian and vehicular surfaces).
3. Functional elements (utility placement, erosion control and environmental mitigation measures).
SECTION 8-1002 — APPLICATION

8-1002.1 The CHBC shall apply to all sites and districts and their features associated with qualified historical buildings or qualified historical districts as outlined in 8-1001.2 Scope.

8-1002.2 Where the application of regular code may impact the associated features of qualified historical properties beyond their footprints, by work performed secondarily, those impacts shall also be covered by the CHBC.

8-1002.3 This chapter shall be applied for all issues regarding code compliance or other standard or regulation as they affect the purpose of this chapter.

8-1002.4 The application of any code or building standard shall not unduly restrict the use of a qualified historical building or property that is otherwise permitted pursuant to Chapter 8-3 and the intent of the State Historical Building Code, Section 18956.

SECTION 8-1003 — SITE RELATIONS

The relationship between a building or property and its site, or the associated features of a district (including qualified historical landscape), site, objects and their features are critical components that may be one of the criteria for these buildings and properties to be qualified under the CHBC. The CHBC recognizes the importance of these relationships. This chapter shall be used to provide context sensitive solutions for treatment of qualified historical buildings, properties, district or their associated historical features, or when work to be performed secondarily impacts the associated historical features of a qualified historical building or property.

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CHBC § 8-904.2.7 High relevance — show source text
8-904.2.7 Lighting load calculations for services and feeders may be based on actual loads as installed in lieu of the “watts per square foot” method.

8-904.2.8 Determination of existing loads may be based on maximum demand recordings in lieu of calculations, provided all of the following are met:
1. Recordings are provided by the serving agency.
2. The maximum demand data is available for a one-year period. Exception: If maximum demand data for a one-year period is not available, the maximum demand data shall be permitted to be based on the actual amperes continuously recorded over a minimum 30-day period by a recording ammeter connected to the highest loaded phase of the feeder or service. The recording should reflect the maximum demand when the building or space is occupied and include the measured or calculated load at the peak time of the year, including the larger of the heating or cooling equipment load.
3. There has been no change in occupancy or character of load during the previous 12 months.
4. The anticipated load will not change, or the existing demand load at 125 percent plus the new load does not exceed the ampacity of the feeder or rating of the service.
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8-10 QUALIFIED HISTORICAL DISTRICTS, SITES AND OPEN SPACES

SECTION 8-1001 — PURPOSE AND SCOPE

8-1001.1 Purpose. The purpose of this chapter is to provide regulations for the preservation, rehabilitation, restoration and reconstruction of associated historical features of qualified historical buildings, properties or districts (as defined in Chapter 8-2), and for which Chapters 8-3 through 8-9 of the CHBC may not apply.

8-1001.2 Scope. This chapter applies to the associated historical features of qualified historical buildings or properties such as historical districts that are beyond the buildings themselves which include, but are not limited to, natural features and designed site and landscape plans with natural and man-made landscape elements that support their function and aesthetics. This may include, but will not be limited to:
1. Site plan layout configurations and relationships (pedestrian, equestrian and vehicular site circulation, topographical grades and drainage, and use areas).
2. Landscape elements (plant materials, site structures other than the qualified historical building, bridges and their associated structures, lighting, water features, art ornamentation, and pedestrian, equestrian and vehicular surfaces).
3. Functional elements (utility placement, erosion control and environmental mitigation measures).
SECTION 8-1002 — APPLICATION

8-1002.1 The CHBC shall apply to all sites and districts and their features associated with qualified historical buildings or qualified historical districts as outlined in 8-1001.2 Scope.

8-1002.2 Where the application of regular code may impact the associated features of qualified historical properties beyond their footprints, by work performed secondarily, those impacts shall also be covered by the CHBC.

8-1002.3 This chapter shall be applied for all issues regarding code compliance or other standard or regulation as they affect the purpose of this chapter.
CHBC § 8-706.3 Medium relevance — show source text
8-706.3 Load path. A complete and continuous load path, including connections, from every part or portion of the structure to the ground shall be provided for the required forces. It shall be verified that the structure is adequately tied together to perform as a unit when subjected to earthquake forces.

8-706.4 Parapets. Parapets and exterior decoration shall be investigated for conformance with regular code requirements for anchorage and ability to resist prescribed seismic forces.

An exception to regular code requirements shall be permitted for those parapets and decorations which are judged not to be a hazard to life safety.

8-706.5 Nonstructural features. Nonstructural features of historical structure, such as exterior veneer, cornices and decorations, which might fall and create a life safety hazard in an earthquake, shall be evaluated. Their ability to resist seismic forces shall be verified, or the feature shall be strengthened with improved anchorage when appropriate.

8-706.5.1 Partitions and ceilings of corridors and stairways serving an occupant load of 30 or more shall be investigated to determine their ability to remain in place when the building is subjected to earthquake forces.

8-706.5.2 Seismic forces used to evaluate and improve nonstructural components and their anchorage, where required, shall comply with ASCE 41 or need not exceed 0.75 times the seismic forces prescribed by the requirements of the regular code.

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8-8 ARCHAIC MATERIALS AND METHODS OF CONSTRUCTION

SECTION 8-801 — PURPOSE, INTENT AND SCOPE

8-801.1 Purpose. The purpose of the CHBC is to provide regulations for the use of historical methods and materials of construction that are at variance with regular code requirements or are not otherwise codified, in buildings or structures designated as qualified historical buildings or properties. The CHBC require enforcing agencies to accept any reasonably equivalent alternatives to the regular code when dealing with qualified historical buildings or properties.

8-801.2 Intent. It is the intent of the CHBC to provide for the use of historical methods and materials of construction that are at variance with specific code requirements or are not otherwise codified.

8-801.3 Scope. Any construction type or material that is, or was, part of the historical fabric of a structure is covered by this chapter. Archaic materials and methods of construction present in a historical structure may remain or be reinstalled or be installed with new materials of the same class to match existing conditions.

SECTION 8-802 — GENERAL ENGINEERING APPROACHES

Strength values for archaic materials shall be assigned based upon similar conventional codified materials, or on tests as hereinafter indicated. The archaic materials and methods of construction shall be thoroughly investigated for their details of construction in accordance with Section 8-703. Testing shall be performed when applicable to evaluate existing conditions. The architect or structural engineer in responsible charge of the project shall assign allowable stresses or strength levels to archaic materials. Such assigned strength values shall not be greater than those provided for in the following sections without adequate testing, and shall be subject to the concurrence of the enforcing agency.

SECTION 8-803 — NONSTRUCTURAL ARCHAIC MATERIALS
CHBC § 8-3 Medium relevance — show source text
This shall include historical buildings or properties on, or determined eligible for, national, state or local historical registers or inventories, such as the National Register of Historic Places, California Register of Historical Resources, State Historical Landmarks, State Points of Historical Interest, and city or county registers, inventories or surveys of historical or architecturally significant sites, places or landmarks.

RECONSTRUCTION. The act or process of depicting, by means of new construction, the form, features and detailing of a nonsurviving site, landscape, building, property or object for the purpose of replicating its appearance at a specific period of time.

REGULAR CODE. The adopted regulations that govern the design and construction or alteration of nonhistorical buildings and properties within the jurisdiction of the enforcing agency.

REHABILITATION. The act or process of making possible a compatible use for qualified historical building or property through repair, alterations and additions while preserving those portions or features which convey its qualified historical, cultural or architectural values.

RELOCATION. The act or process of moving any qualified historical building or property or a portion of a qualified historical building or property to a new site, or a different location on the same site.

REPAIR. Renewal, reconstruction or renovation of any portion of an existing property, site or building for the purpose of its continued use.

RESTORATION. The act or process of accurately depicting the form, features and character of a qualified building or property as it appeared at a particular period of time by the means of the removal of features from other periods in its history and reconstruction of missing features from the restoration period. The limited and sensitive upgrading of mechanical, electrical and plumbing systems and other code-required work to make properties functional is appropriate within a restoration project.

STRUCTURE. That which is built or constructed, an edifice or a building of any kind, or any piece of work artificially built up or composed of parts joined together in some definite manner.

TREATMENT. An act of work to carry out preservation, restoration, stabilization, rehabilitation or reconstruction.

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8-3 USE AND OCCUPANCY

SECTION 8-301 — PURPOSE AND SCOPE

8-301.1 Purpose. The purpose of the CHBC is to provide regulations for the determination of occupancy classifications and conditions of use for qualified historical buildings or properties.

8-301.2 Scope. Every qualified historical building or property for which a permit or approval has been requested shall be classified prior to permit issuance according to its use or the character of its occupancy in accordance with the regular code and applicable provisions of this chapter.

SECTION 8-302 — GENERAL

8-302.1 Existing use. The use or character of occupancy of a qualified historical building or property, or portion thereof, shall be permitted to continue in use regardless of any period of time in which it may have remained unoccupied or in other uses, provided such building or property otherwise conforms to all applicable requirements of the CHBC.

8-302.2 Change in occupancy. The use or character of the occupancy of a qualified historical building or property may be changed from or returned to its historical use or character, provided the qualified historical building or property conforms to the requirements applicable to the new use or character of occupancy as set forth in the CHBC. Such change in occupancy shall not mandate conformance with new construction requirements as set forth in regular code.
CHBC § 4.00 Medium relevance — show source text
10
wood screw|1|24|4.00|0.90|DR|DR|2.85|DR|DR|DR| |Minimum 1x
Wood Furringd|Minimum 2x
Wood Stud|1/4" lag screw|11/2|12|4.00|2.65|1.50|0.90|4.00|1.65|0.80|DR| |Minimum 1x
Wood Furringd|Minimum 2x
Wood Stud|1/4" lag screw|11/2|16|4.00|1.95|0.95|0.50|4.00|1.10|DR|DR| |Minimum 1x
Wood Furringd|Minimum 2x
Wood Stud|1/4" lag screw|11/2|24|4.00|1.10|DR|DR|3.25|0.50|DR|DR| |For SI: 1 inch = 25.4 mm, 1 pound per square foot (psf) = 0.0479 kPa, 1 pound per square inch = 0.00689 MPa.
DR = Design Required, o.c. = on center.
a. Wood framing and furring shall be spruce-pine-fir or any wood species with a specific gravity of 0.42 or greater in accordance with ANSI/AWC NDS.
b. Nail fasteners shall comply with ASTM F1667, except nail length shall be permitted to exceed ASTM F1667 standard lengths.
c. The thickness of wood structural panels complying with the specific gravity requirements of Note a shall be permitted to be included in satisfying the minimum required
penetration into framing.
d. Where the required cladding fastener penetration into wood material exceeds3/4 inch and is not more than 11/2 inches, a minimum 2-inch nominal wood furring or an
approved design shall be used.
e. Foam sheathing shall have a minimum compressive strength of 15 psi in accordance with ASTM C578 or ASTM C1289.
f. Furring shall be spaced not greater than 24 inches on center in a vertical or horizontal orientation. In a vertical orientation, furring shall be located over wall studs and attached with
the required fastener spacing. In a horizontal orientation, the indicated 8-inch and 12-inch fastener spacing in furring shall be achieved by use of two fasteners into studs at 16 inches
and 24 inches on center, respectively.|For SI: 1 inch = 25.4 mm, 1 pound per square foot (psf) = 0.0479 kPa, 1 pound per square inch = 0.00689 MPa.
DR = Design Required, o.c. = on center.
a. Wood framing and furring shall be spruce-pine-fir or any wood species with a specific gravity of 0.42 or greater in accordance with ANSI/AWC NDS.
b. Nail fasteners shall comply with ASTM F1667, except nail length shall be permitted to exceed ASTM F1667 standard lengths.
c. The thickness of wood structural panels complying with the specific gravity requirements of Note a shall be permitted to be included in satisfying the minimum required
penetration into framing.
d. Where the required cladding fastener penetration into wood material exceeds3/4 inch and is not more than 11/2 inches, a minimum 2-inch nominal wood furring or an
approved design shall be used.
e.
CHBC § 323-9843 Medium relevance — show source text
State Librarian [SL]

library.ca.gov csllaw@library.ca.gov (916) 323-9843 Public Library Construction & Renovation

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HOW TO DETERMINE WHERE CHANGES HAVE BEEN MADE

Symbols in the margins indicate where changes have been made or language has been deleted.

This symbol indicates that a change has been made.
- This symbol indicates deletion of language.
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PART 8 CONTAINS ALTERNATIVE REGULATIONS

FOR QUALIFIED HISTORICAL BUILDINGS

The California Historical Building Code (CHBC) is unique among state regulations. The authoring of the original CHBC required state agencies promulgating regulations for building construction to work in harmony with representatives of other design and construction disciplines. The result was a totally new approach to building codes for historical structures, which maintains currently acceptable life safety standards. These regulations are also unique in that they are performance oriented rather than prescriptive. The provisions of the CHBC are to be applied by the enforcing authority of every city, county, city and county, or state agency in permitting repairs, alterations and additions necessary for the preservation, rehabilitation, relocation, related construction, change of use or continued use of a qualified historical building. The authority for use of the CHBC is vested in Sections 18950 through 18961 of the Health and Safety Code. Section 18954 states, “The building department of every city or county or other local agency that has jurisdiction over the enforcement of code within its legal authority shall apply the alternative standards and regulations adopted pursuant to Section 18959.5 in permitting repairs, alterations, and additions necessary for the preservation, restoration, rehabilitation, safety, moving, or continued use of a qualified historical building or structure. A state agency shall apply the alternative regulations adopted pursuant to Section 18959.5 in permitting repairs, alterations, and additions necessary for the preservation, restoration, rehabilitation, safety, moving, or continued use of a qualified historical building or structure.” However, be aware that in order to use the CHBC, the structure under consideration must be qualified by being designated as an historical building or structure. Section 18955 states, “For the purposes of this part, a qualified historical building or structure is any structure or property, collection of structures, and their related sites deemed of importance to the history, architecture, or culture of an area by an appropriate local or state governmental jurisdiction. This shall include historical buildings or structures on existing or future national, state or local historical registers or official inventories, such as the National Register of Historic Places, State Historical Landmarks, State Points of Historical Interest, and city or county registers or inventories of historical or architecturally significant sites, places, historic districts, or landmarks. This shall also include places, locations, or sites identified on these historical registers or official inventories and deemed of importance to the history, architecture, or culture of an area by an appropriate local or state governmental jurisdiction.” The regulations of the CHBC have the same authority as state law and are to be considered as such. Liability is the same as for prevailing law. The intent of the CHBC is to save California’s architectural heritage by recognizing the unique construction problems inherent in historical buildings and by providing a code to deal with these problems.
California Historical Building Code Medium relevance — show source text
|100 psf|1 hr
23 min|||7|1, 2|11/3| |F/C-4-RC-9|4″|4″ deep (4370 psi);1/4″ reinforcement bars
at 6″ pitch with3/4″ cover;1/4″ main rein-
forcement bars at 4″ pitch perpendicular
with1/2″ cover; 13′1″ span restrained.|150 psf|2 hrs|||7|1, 3|2| |F/C-4-RC-10|4″|4″ thick (5140 psi) deck;1/4″ reinforce-
ment bars at 71/2″ pitch with7/8″ cover;3/8″
main reinforcement bars at 33/4″ pitch
perpendicular with1/2″ cover; 13′1″ span
restrained.|140 psf|1 hr
16 min|||7|1, 5|11/4| |F/C-4-RC-11|4″|4″ thick (4000 psi) concrete deck;
3″ × 11/2″ × 4 lbs R.S.J.; 2′6″ C.R.S.; flush
with top surface; 4″ × 6″ x 13 SWG mesh
reinforcement 1″ from bottom of slab; 6′6″
span restrained.|150 psf|2 hrs|||7|1, 3|2| |F/C-4-RC-12|4″|4″ deep (2380 psi) concrete deck;
3″ × 11/2″ × 4 lbs R.S.J.; 2′6″ C.R.S.; flush
with top surface; 4″ × 6″ x 13 SWG mesh
reinforcement 1″ from bottom surface;
6′6″ span restrained.|150 psf|1 hr
3 min|||7|1, 2|1| |F/C-4-RC-13|41/2″|41/2″ thick (5200 psi) deck;1/4″ reinforce-
ment bars at 71/4″ pitch with7/8″ cover;3/8″
main reinforcement bars at 33/4″ pitch
perpendicular with1/2″ cover; 13′1″ span
restrained.|140 psf|2 hrs|||7|1, 3|2| |F/C-4-RC-14|41/2″|41/2″ deep (2525 psi) concrete deck;1/4″
reinforcement bars at 71/2″ pitch with7/8″
cover;3/8″ main reinforcement bars at
33/8″ pitch perpendicular with1/2″ cover;
13′1″ span restrained.|150 psf|42 min|||7|1, 5|2/3| |F/C-4-RC-15|41/2″|41/2″ deep (4830 psi) concrete deck;
11/2″ × No.
CHBC § 7-4 Medium relevance — show source text
pine|#2|7-4|11-0|13-11|16-6|19-6|6-4|9-6|12-1|14-4|16-10| |24|Southern pine|#3|5-8|8-4|10-6|12-9|15-1|4-11|7-3|9-1|11-0|13-1| |24|Spruce-pine-fir|SS|7-8|12-0|15-10|20-2|24-7|7-8|12-0|15-4|18-9|21-9| |24|Spruce-pine-fir|#1|7-6|11-9|14-10|18-2|21-0|6-11|10-2|12-10|15-8|18-3| |24|Spruce-pine-fir|#2|7-6|11-9|14-10|18-2|21-0|6-11|10-2|12-10|15-8|18-3| |24|Spruce-pine-fir|#3|6-1|8-10|11-3|13-8|15-11|5-3|7-8|9-9|11-10|13-9| |Check sources for availability of lumber in lengths greater than 20 feet.
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa.
a. The tabulated rafter spans assume that ceiling joists are located at the bottom of the attic space or that some other method of resisting the outward push of the rafters on the
bearing walls, such as rafter ties, is provided at that location. Where ceiling joists or rafter ties are located higher in the attic space, the rafter spans shall be multiplied by the
adjustment factors in Table R802.4.1(9).
b. Span exceeds 26 feet in length.|Check sources for availability of lumber in lengths greater than 20 feet.
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa.
a. The tabulated rafter spans assume that ceiling joists are located at the bottom of the attic space or that some other method of resisting the outward push of the rafters on the
bearing walls, such as rafter ties, is provided at that location. Where ceiling joists or rafter ties are located higher in the attic space, the rafter spans shall be multiplied by the
adjustment factors in Table R802.4.1(9).
b. Span exceeds 26 feet in length.|Check sources for availability of lumber in lengths greater than 20 feet.
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa.
a. The tabulated rafter spans assume that ceiling joists are located at the bottom of the attic space or that some other method of resisting the outward push of the rafters on the
bearing walls, such as rafter ties, is provided at that location. Where ceiling joists or rafter ties are located higher in the attic space, the rafter spans shall be multiplied by the
adjustment factors in Table R802.4.1(9).
b.
CHBC § 5-8 Medium relevance — show source text
pine|#3|5-8|8-4|10-6|12-9|15-1|4-11|7-3|9-1|11-0|13-1| |24|Spruce-pine-fir|SS|8-5|13-3|17-5|21-8|25-2|8-4|12-2|15-4|18-9|21-9| |24|Spruce-pine-fir|#1|8-0|11-9|14-10|18-2|21-0|6-11|10-2|12-10|15-8|18-3| |24|Spruce-pine-fir|#2|8-0|11-9|14-10|18-2|21-0|6-11|10-2|12-10|15-8|18-3| |24|Spruce-pine-fir|#3|6-1|8-10|11-3|13-8|15-11|5-3|7-8|9-9|11-10|13-9| |Check sources for availability of lumber in lengths greater than 20 feet.
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa.
a. The tabulated rafter spans assume that ceiling joists are located at the bottom of the attic space or that some other method of resisting the outward push of the rafters on the
bearing walls, such as rafter ties, is provided at that location. Where ceiling joists or rafter ties are located higher in the attic space, the rafter spans shall be multiplied by the
adjustment factors in Table R802.4.1(9).
b. Span exceeds 26 feet in length.|Check sources for availability of lumber in lengths greater than 20 feet.
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa.
a. The tabulated rafter spans assume that ceiling joists are located at the bottom of the attic space or that some other method of resisting the outward push of the rafters on the
bearing walls, such as rafter ties, is provided at that location. Where ceiling joists or rafter ties are located higher in the attic space, the rafter spans shall be multiplied by the
adjustment factors in Table R802.4.1(9).
b. Span exceeds 26 feet in length.|Check sources for availability of lumber in lengths greater than 20 feet.
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa.
a. The tabulated rafter spans assume that ceiling joists are located at the bottom of the attic space or that some other method of resisting the outward push of the rafters on the
bearing walls, such as rafter ties, is provided at that location. Where ceiling joists or rafter ties are located higher in the attic space, the rafter spans shall be multiplied by the
adjustment factors in Table R802.4.1(9).
b.
CHBC § 10-8 Medium relevance — show source text
000|10-8|12-6|9-8|10-0|9-0|8-2|7-7|6-4|6-2| |24|2-#4
1-#6|60,000|12-11|15-2|11-9|12-2|11-0|9-11|9-3|7-8|7-6| |24|2-#5|40,000|15-2|17-9|13-9|14-3|12-10|11-7|10-10|9-0|8-9| |24|2-#5|60,000|18-4|21-6|16-7|17-3|15-6|14-0|13-1|10-4|10-0| |24|2-#6|40,000|18-0|21-1|16-4|16-11|14-10|12-9|11-8|9-2|8-11| |24|2-#6|60,000|21-7|25-4|19-2|20-4|17-2|14-9|13-4|10-4|10-0| |24|Center distance_A_k, l|Center distance_A_k, l|4-6|6-2|3-8|4-0|3-3|2-8|2-3|1-7|1-6| |For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square inch = 6.895 kPa, 1 pound per square foot = 0.0479 kPa, Grade 40 = 280 MPa, Grade 60 = 420 MPa.
a. See Table R608.3 for tolerances permitted from nominal thickness.
b. Table values are based on concrete with a minimum specified compressive strength of 2,500 psi. See Note j.
c. Table values are based on uniform loading. See Section R608.8.2 for lintels supporting concentrated loads.
d. Deflection criterion is_L_/240, where_L_ is the clear span of the lintel in inches, or1/2 inch, whichever is less.
e. Linear interpolation is permitted between ground snow loads and between lintel depths.
f. DR indicates design required.
g. Lintel depth,D, is permitted to include the available height of wall located directly above the lintel, provided that the increased lintel depth spans the entire length of the
lintel.
h. Stirrups shall be fabricated from reinforcing bars with the same yield strength as that used for the main longitudinal reinforcement.
i. Allowable clear span without stirrups applicable to all lintels of the same depth,D. Top and bottom reinforcement for lintels without stirrups shall be not less than the least
amount of reinforcement required for a lintel of the same depth and loading condition with stirrups. All other spans require stirrups spaced at not more than_d_/2.
j. Where concrete with a minimum specified compressive strength of 3,000 psi is used, clear spans for lintels without stirrups shall be permitted to be multiplied by 1.05.
CHBC § 1.05. Medium relevance — show source text
All other spans require stirrups spaced at not more than 12 inches.
m.Where concrete with a minimum specified compressive strength of 3,000 psi is used, clear spans for lintels without stirrups shall be permitted to be multiplied by 1.05. If the
increased span exceeds the allowable clear span for a lintel of the same depth and loading condition with stirrups, the top and bottom reinforcement shall be equal to or
greater than that required for a lintel of the same depth and loading condition that has an allowable clear span that is equal to or greater than that of the lintel without stir-
rups that has been increased.
n. Center distance,A, is the center portion of the span where stirrups are not required. This is applicable to all longitudinal bar sizes and steel yield strengths.
o. Where concrete with a minimum specified compressive strength of 3,000 psi is used, center distance,A, shall be permitted to be multiplied by 1.10.
p. The maximum clear opening width between two solid wall segments shall be 18 feet. See Section R608.7.2.1. Lintel spans in the table greater than 18 feet are shown for inter-
polation and information only.|For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square inch = 6.895 kPa, 1 pound per square foot = 0.0479 kPa, Grade 40 = 280 MPa, Grade 60 = 420 MPa.
a. Where lintels are formed with screen-grid forms, form material shall be removed if necessary to create top and bottom flanges of the lintel that are not less than 5 inches in
width and not less than 2.5 inches in depth (in the vertical direction). See Figure R608.8(4). Flat-form lintels shall be permitted in lieu of screen-grid lintels. See Tables
R608.8(2) through R608.8(5).
b. See Table R608.3 for tolerances permitted from nominal thickness and minimum dimensions and spacings of cores.
c. Table values are based on concrete with a minimum specified compressive strength of 2,500 psi. See Notes m and o. Table values are based on uniform loading. See Section
R608.7.2.1 for lintels supporting concentrated loads.
d. Deflection criterion is_L_/240, where_L_ is the clear span of the lintel in inches, or1/2 inch, whichever is less.
e. Linear interpolation is permitted between ground snow loads.
f. DR indicates design required. STL indicates stirrups required throughout lintel.
g. Lintel depth,D, is permitted to include the available height of wall located directly above the lintel, provided that the increased lintel depth spans the entire length of the
lintel.
h. Stirrups shall be fabricated from reinforcing bars with the same yield strength as that used for the main longitudinal reinforcement.
i. Stirrups are not required for lintels less than 24 inches in depth fabricated from screen-grid forms. Top and bottom reinforcement shall consist of a No. 4 bar having a yield
strength of 40,000 psi or 60,000 psi.
j.

Frequently asked questions

When exactly does § 8-1002.2 kick in?

When a proposed application of the regular code would have an effect on historic associated features beyond the building footprint through work done outside the building (i.e., secondary work). In that circumstance the CHBC governs the impacts.

Does minor landscaping (e.g., planting a tree) trigger the CHBC?

If the planting materially affects the historic landscape or other associated features identified in the CHBC scope, then it may trigger CHBC review; otherwise minor, non-impacting actions typically will not. The CHBC lists examples of associated features in § 8-1001.2.

What if applying the regular code would be safer but would alter historic character?

The CHBC requires a balance: do not unduly restrict permitted use under § 8-1002.4, but safety is important. Use CHBC’s performance-based alternatives and coordinate with the enforcing agency to find an acceptable solution.

Who decides whether the CHBC applies to secondary work?

The enforcing agency (building department or state agency) applies the CHBC when the criteria in § 8-1002.2 are met; applicants should document impacts and propose context-sensitive alternatives.

If the CHBC applies, do I ignore the regular code?

No — the CHBC provides alternative, performance-based regulations for qualified historical buildings/properties where appropriate. It does not remove life-safety responsibilities; instead it allows context-sensitive compliance paths.

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Related in the CHBC

How are relocated qualified historical buildings sited and what rules apply?

What rules govern repairs, additions, reconstruction and in-kind work on sites and landscapes?

Application, relocation and siting rules

California Historical Building Code