Skip to content

Chapter 8 — COMPLIANCE FORMS, WORKSHEETS AND REFERENCE MATERIAL

Section A5.105 — DECONSTRUCTION AND REUSE OF EXISTING STRUCTURES

2025 California Green Building Standards Code (Title 24, Part 11) · 2025 edition · updated 2026-07-25 · California

A5.105.1 Scope. Projects with the area limits specified shall comply with Section A5.105.2 to achieve Tier 1 or Tier 2 compliance.

  1. Alteration(s) to existing building(s) where the combined altered floor area is 50,000 square feet or greater shall comply with either Section A5.105.2, Section A5.409.2, or Section A5.409.3.
  2. Addition(s) to existing building(s) where the total floor area combined with the existing building(s) is 50,000 square feet or greater shall comply with either Section A5.105.2, Section A5.409.2, or Section A5.409.3. Exception: Combined addition(s) to existing building(s) of two times the area or more of the existing building(s) is not eligible to meet compliance with Section A5.105.2.
  3. Alteration(s) to existing building(s) where the aggregate floor area is less than 50,000 square feet shall comply with either Section 5.105.2, Section 5.409.2 or Section 5.409.3 for Tier 1 compliance, and either Section A5.105.2.1, Section A5.409.2.1, or A5.409.3 Tier 1 requirements for Tier 2 compliance.
  4. Addition(s) to an existing building where the total floor area combined with the existing building(s) is less than 50,000 square feet shall comply with either Section 5.105.2, Section 5.409.2 or Section 5.409.3 for Tier 1 compliance, and either Section A5.105.2.1, Section A5.409.2.1, or A5.409.3 Tier 1 requirements for Tier 2 compliance. Exception: Combined addition(s) to existing building(s) of two times the area or more of the existing building(s) is not eligible to meet compliance with Section 5.105.2 or Section A5.105.2.

A5.105.2 Reuse of existing building. Projects that include the reuse of an existing building shall meet the minimum requirements of Section A5.105.2.

A5.105.2.1 Tier 1: An alteration or addition to an existing building shall maintain at least 75 percent combined of the existing building’s primary structural elements (foundations; columns, beams, walls, and floors; and lateral elements) and existing building enclosure (roof framing, wall framing and exterior finishes). Window assemblies, insulation, portions of buildings deemed structurally unsound or hazardous, and hazardous materials that are remediated as part of the project shall not be included in the calculation.

A5.105.2.2 Tier 2: An alteration or addition to an existing building shall maintain at least 75 percent combined of the existing building’s primary structural elements (foundations; columns, beams, walls, and floors; and lateral elements) and existing building enclosure (roof framing, wall framing and exterior finishes). In addition, an alteration to an existing building shall maintain 30 percent of existing interior nonstructural elements (interior walls, doors, floor coverings, ceiling systems). Window assemblies, insulation, portions of buildings deemed structurally unsound or hazardous, and hazardous materials that are remediated as part of the project shall not be included in the calculation.

APPENDIX A5-4 2025 CALIFORNIA GREEN BUILDING STANDARDS CODE

on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

APPENDIX A5 — NONRESIDENTIAL VOLUNTARY MEASURES

A5.105.2.3 Verification of compliance. Documentation shall be provided in the construction documents to demonstrate compliance with Section A5.105.2.

Note: Sample Worksheet WS-6 in Chapter 8 may be used to assist in documenting compliance with this section.

A5.105.3 Deconstruction (Reserved).

Get a plain-English answer with a citation back to this text.

Ask AI about this code
▸ Contents — 2025 California Green Building Standards Code (Title 24, Part 11)
2025 California Green Building Standards Code (Title 24, Part 11)
  1. Chapter 1 — ADMINISTRATION
  2. Chapter 2 — DEFINITIONS
  3. Chapter 3 — GREEN BUILDING
  4. Chapter 4 — RESIDENTIAL MANDATORY MEASURES
  5. Chapter 4 — RESIDENTIAL MANDATORY MEASURES
  6. Chapter 4 — RESIDENTIAL MANDATORY MEASURES
  7. Chapter 4 — RESIDENTIAL MANDATORY MEASURES
  8. Chapter 4 — RESIDENTIAL MANDATORY MEASURES
  9. Chapter 5 — NONRESIDENTIAL MANDATORY MEASURES
  10. Chapter 5 — NONRESIDENTIAL MANDATORY MEASURES
  11. Chapter 5 — NONRESIDENTIAL MANDATORY MEASURES
  12. Chapter 5 — NONRESIDENTIAL MANDATORY MEASURES
  13. Chapter 5 — NONRESIDENTIAL MANDATORY MEASURES
  14. Chapter 6 — REFERENCED ORGANIZATIONS AND STANDARDS
  15. Chapter 7 — INSTALLER AND SPECIAL INSPECTOR QUALIFICATIONS
  16. ▸ Chapter 8 — COMPLIANCE FORMS, WORKSHEETS AND REFERENCE MATERIAL
    Overview
    1. Section A4.101 — GENERAL
    2. Section A4.102 — DEFINITIONS
    3. Section A4.103 — SITE SELECTION
    4. Section A4.104 — SITE PRESERVATION
    5. Section A4.105 — DECONSTRUCTION AND REUSE OF EXISTING MATERIALS
    6. Section A4.106 — SITE DEVELOPMENT
    7. Section A4.107
    8. Section A4.108 — INNOVATIVE CONCEPTS AND LOCAL ENVIRONMENTAL C…
    9. Section A4.201 — GENERAL
    10. Section A4.202 — DEFINITIONS
    11. Section A4.203 — PERFORMANCE APPROACH FOR NEWLY CONSTRUCTED BU…
    12. Section A4.204 — REQUIREMENTS FOR ALTERATIONS TO EXISTING BUIL…
    13. Section A4.301 — GENERAL
    14. Section A4.302 — DEFINITIONS
    15. Section A4.303 — INDOOR WATER USE
    16. Section A4.304 — OUTDOOR WATER USE
    17. Section A4.305 — WATER REUSE SYSTEMS
    18. Section A4.306 — INNOVATIVE CONCEPTS AND LOCAL ENVIRONMENTAL C…
    19. Section A4.401 — GENERAL
    20. Section A4.402 — DEFINITIONS
    21. Section A4.403 — FOUNDATION SYSTEMS
    22. Section A4.404 — EFFICIENT FRAMING TECHNIQUES
    23. Section A4.405 — MATERIAL SOURCES
    24. Section A4.406 — ENHANCED DURABILITY AND REDUCED MAINTENANCE
    25. Section A4.407 — WATER RESISTANCE AND MOISTURE MANAGEMENT
    26. Section A4.408 — CONSTRUCTION WASTE REDUCTION, DISPOSAL AND RE…
    27. Section A4.409 — LIFE CYCLE ASSESSMENT
    28. Section A4.410 — BUILDING MAINTENANCE AND OPERATION
    29. Section A4.411 — INNOVATIVE CONCEPTS AND LOCAL ENVIRONMENTAL C…
    30. Section A4.501 — GENERAL
    31. Section A4.502 — DEFINITIONS
    32. Section A4.503 — FIREPLACES
    33. Section A4.504 — POLLUTANT CONTROL
    34. Section A4.505 — INTERIOR MOISTURE CONTROL
    35. Section A4.506 — INDOOR AIR QUALITY AND EXHAUST
    36. Section A4.507 — ENVIRONMENTAL COMFORT
    37. Section A4.508 — OUTDOOR AIR QUALITY
    38. Section A4.509 — INNOVATIVE CONCEPTS AND LOCAL ENVIRONMENTAL C…
    39. Section A4.601 — GENERAL
    40. Section A4.602 — RESIDENTIAL OCCUPANCIES APPLICATION CHECKLIST
    41. Section A4.602 — RESIDENTIAL OCCUPANCIES APPLICATION CHECKLIST…
    42. Section A4.602 — RESIDENTIAL OCCUPANCIES APPLICATION CHECKLIST…
    43. Section A4.602 — RESIDENTIAL OCCUPANCIES APPLICATION CHECKLIST…
    44. Section A4.602 — RESIDENTIAL OCCUPANCIES APPLICATION CHECKLIST…
    45. Section A4.602 — RESIDENTIAL OCCUPANCIES APPLICATION CHECKLIST…
    46. Section A4.602 — RESIDENTIAL OCCUPANCIES APPLICATION CHECKLIST…
    47. Section A5.101 — GENERAL
    48. Section A5.102 — DEFINITIONS
    49. Section A5.103 — SITE SELECTION
    50. Section A5.104 — SITE PRESERVATION
    51. Section A5.105 — DECONSTRUCTION AND REUSE OF EXISTING STRUCTURES
    52. Section A5.106 — SITE DEVELOPMENT
    53. Section A5.107 — BIRD-FRIENDLY BUILDING DESIGN
    54. Section A5.201 — GENERAL
    55. Section A5.202 — DEFINITIONS
    56. Section A5.203 — PERFORMANCE APPROACH
    57. Section A5.204 — MANDATORY REQUIREMENTS FOR ALTERATIONS TO EXI…
    58. Section A5.211 — RESERVED
    59. Section A5.212 — ELEVATORS, ESCALATORS AND OTHER EQUIPMENT
    60. Section A5.213 — ENERGY EFFICIENT FRAMING
    61. Section A5.301 — GENERAL
    62. Section A5.302 — DEFINITIONS
    63. Section A5.303 — INDOOR WATER USE
    64. Section A5.304 — OUTDOOR WATER USE
    65. Section A5.305 — WATER REUSE
    66. Section A5.401 — GENERAL
    67. Section A5.402 — DEFINITIONS
    68. Section A5.403 — FOUNDATION SYSTEMS
    69. Section A5.404 — EFFICIENT FRAMING TECHNIQUES
    70. Section A5.405 — MATERIAL SOURCES
    71. Section A5.406 — ENHANCED DURABILITY AND REDUCED MAINTENANCE
    72. Section A5.408 — CONSTRUCTION WASTE REDUCTION, DISPOSAL AND RE…
    73. Section A5.409 — LIFE CYCLE ASSESSMENT
    74. Section A5.501 — GENERAL
    75. Section A5.502 — DEFINITIONS
    76. Section A5.504 — POLLUTANT CONTROL
    77. Section A5.507 — ENVIRONMENTAL COMFORT
    78. Section A5.508 — OUTDOOR AIR QUALITY
    79. Section A6.106 — SITE DEVELOPMENT
    80. Section A6.202 — DEFINITIONS
    81. Section A6.203 — PERFORMANCE APPROACH
    82. Section A6.204 — PRESCRIPTIVE APPROACH
    83. Section A6.205 — [OSHPD 1 & 4]—BUILDING ENVELOPE
    84. Section A6.207 — [OSHPD 1, 2 & 4]—HVAC DESIGN, EQUIPMENT AND I…
    85. Section A6.210 — [OSHPD 1, 2 & 4]—APPLIANCES
    86. Section A6.401 — GENERAL
    87. Section A6.407 — [OSHPD 1, 2 & 4]—WATER RESISTANCE AND MOISTUR…
    88. Section A6.408 — CONSTRUCTION WASTE REDUCTION, DISPOSAL AND RE…
    89. Section A6.410 — BUILDING MAINTENANCE AND OPERATION
    90. Section A6.504 — POLLUTANT CONTROL
    91. Section A6.505 — [OSHPD 1, 2 & 4]—INDOOR MOISTURE CONTROL

GoCodebook provides public access, search, citation, multilingual explanation, and practical interpretation of legally adopted building regulations. It is not a substitute for the official ICC or California code publications.