Chapter 7.94
GREEN BUILDING CODE
Sections:
7.94.030 Adoption of the Green Building Code.
7.94.050 Section 202, Chapter 2 Definitions—Amended.
7.94.060 Section 4.106.4 Electric vehicle (EV) charging for new construction—Deleted and replaced.
7.94.070 Sections 4.106.5, 4.106.5.1, and 4.106.5.2 All-Electric Buildings—Added.
7.94.080 Section 4.107.1, Division 4.1, Chapter 4, Future access for solar systems—Added.
7.94.085 Section 4.420, Division 4.4, Chapter 4, Low Carbon Concrete—Added.
7.94.090 Sections 5.106.5.3 and 5.106.5.3.1 Electric vehicle (EV) charging—Deleted and replaced.
7.94.100 Section 5.106.13, 5.106.13.1 and 5.106.13.2 All electric buildings—Added.
7.94.110 Section 5.107.1, Division 5.1, Chapter 5, Future access for solar systems—Added.
7.94.120 Section 5.420, Division 5.4, Chapter 5, Low Carbon Concrete—Added.
7.94.010 Title.
The green building standards codes adopted by Section 7.94.030 and the provisions of this chapter shall constitute the Dublin Green Building Code and may be referred to as such. (Ord. 13-22 § 13 (Exh. L))
7.94.020 Purpose.
A. To improve public health, safety, and general welfare by enhancing the design and construction of buildings through the use of building concepts having a reduced negative impact or positive environmental impact and encouraging sustainable construction practices in the following categories:
1. Planning and design;
2. Energy efficiency;
3. Water efficiency and conservation;
4. Material conservation and resource efficiency;
5. Environmental quality.
B. The purpose of this code is not to create or otherwise establish or designate any particular class or groups of persons who will or should be especially protected or benefited by the terms of this code. (Ord. 13-22 § 13 (Exh. L))
7.94.030 Adoption of the Green Building Code.
A. The 2022 California Green Building Standards Code, Part 11, Title 24 of the California Code of Regulations, a portion of the California Building Standards Code, as defined in the California Health and Safety Code Section 18901 et seq. (hereinafter referred to as the “state code”), and any rules and regulations promulgated pursuant thereto, as referenced in and adopted pursuant to California Health and Safety Code Sections 17922 and 18935, are hereby adopted and incorporated by reference herein.
Copies of the adopted codes have been and are now filed in the Office of the Building Official, 100 Civic Plaza, Dublin, California, for use and examination by the public. Said codes are adopted by reference pursuant to Section 50022.4 et seq. of the Government Code of the state of California, and the codes are hereby adopted and incorporated as fully as if set out at length herein, and from the date on which the ordinance codified in this chapter shall take effect, the provisions thereof shall be controlling within the limits of the city of Dublin.
B. Notwithstanding the provisions of subsection A of this section, the state code is amended as set forth in Sections 7.94.050 through 7.94.080. (Ord. 13-22 § 13 (Exh. L))
7.94.040 Scope.
A. The provisions of this code shall apply to the planning, design, operation, construction, use and occupancy of every newly constructed building or structure, unless otherwise indicated in this code, within the city.
B. It is not the intent that this code substitute or be identified as meeting the certification requirements of any green building program. (Ord. 13-22 § 13 (Exh. L))
7.94.050 Section 202, Chapter 2 Definitions—Amended.
The following definitions are hereby added to Section 202 of the state code to read as follows:
ALL-ELECTRIC BUILDING. A building that contains no combustion equipment or plumbing for combustion equipment within the building or building property lines, and instead uses electric appliances for service.
ASPHALTIC CONCRETE. Commonly called asphalt, bituminous asphalt concrete, and bituminous mixture, consists of any composite material composed of mineral aggregate adhered with a binder and commonly used to surface roads and parking lots.
CALTRANS AUTHORIZED MATERIALS LIST. Cementitious materials for use in concrete as updated from time to time. This list includes blended cement, Portland cement, fly ash, pozzolan, metakaolin pozzolan, silica fume, and slag materials.
CARBON CURE CONCRETE. A technology that introduces recycled CO₂ into fresh concrete to reduce its carbon footprint without compromising performance. Once injected, the CO₂ undergoes a mineralization process and becomes permanently embedded.
COMMERCIAL FOOD HEAT-PROCESSING EQUIPMENT. Equipment used in a food establishment for heat-processing food or utensils and that produces grease vapors, steam, fumes, smoke, or odors that are required to be removed through a local exhaust ventilation system, as defined in the California Mechanical Code.
COMBUSTION EQUIPMENT. Any equipment or appliance used for space heating, water heating, cooking, clothes drying and/or lighting that uses fuel gas.
CONCRETE. Any approved combination of mineral aggregates bound together into a hardened conglomerate in accordance with the requirements of this code. Concrete as defined in this chapter does not include asphaltic concrete.
CO₂. Carbon dioxide.
CO₂ INJECTION. The process of injecting CO₂ into the cement mixture rather than water for purposes of curing the product.
ELECTRIC HEATING APPLIANCE. A device that produces heat energy to create a warm environment by the application of electric power to resistance elements, refrigerant compressors, or dissimilar material junctions, as defined in the California Mechanical Code.
ENVIRONMENTAL PRODUCT DECLARATION. Present quantified environmental information on the life cycle of a product based on the results of a comprehensive Life Cycle Assessment (LCA) to enable comparisons between products fulfilling the same function. Environmental Product Declarations must conform to International Organization for Standardization 14025 accreditation and European Standard EN 15804, or International Organization for Standardization 21930 accreditation, and have at least a “cradle to grave” scope (which covers product life cycle from resource extraction to the factory).
FUEL GAS. A gas that is natural, manufactured, liquefied petroleum, or a mixture of these.
GREENHOUSE GAS (GHG). Any gas that has the property of absorbing infrared radiation (net heat energy) emitted from Earth’s surface and reradiating it back to Earth’s surface, thus contributing to the greenhouse effect. GHG gases include carbon dioxide, methane, nitrous oxides, and water vapor.
PLAIN CONCRETE. Concrete that contains no steel reinforcement in the form of rods, bars, or mesh or containing not more than two-tenths of one percent of reinforcing.
READY-MIX CONCRETE. Concrete that is batched for delivery from a central plant instead of being mixed on the job site. Each batch of ready-mixed concrete is tailor-made according to the specifics of the contractor and is delivered to the contractor in a plastic condition, usually in the cylindrical trucks often known as cement mixers.
REINFORCED CONCRETE. Concrete in which reinforcing steel in the form of rods, bars, or mesh—is inserted into the concrete to absorb the tensile, shear, and sometimes compressive stresses in a concrete structure.
SECONDARY CEMENTITIOUS MATERIALS (SCMs). Materials that include, but are not limited to, ground granulated blast furnace slag (ggbs), fly ash, metakaolin pozzolan, pozzolan, silica fume, and Belterra clay.
UPFRONT EMBODIED CARBON (EMBODIED CARBON). The emissions, including greenhouse gases, released before the built asset is used. The release of emissions occurs in material extraction, transportation, manufacturing, and installing building materials on site. Upfront embodied carbon also includes operational and end-of-life emissions associated with materials.
(Ord. 9-24 § 8; Ord. 13-22 § 13 (Exh. L))
7.94.060 Section 4.106.4 Electric vehicle (EV) charging for new construction—Deleted and replaced.
Section 4.106.4 is deleted and replaced with Section A4.106.8 to read:
A4.106.8 Electric vehicle (EV) charging for new construction is adopted as mandatory at the Tier 2 level.
(Ord. 13-22 § 13 (Exh. L))
7.94.070 Sections 4.106.5, 4.106.5.1, and 4.106.5.2 All-Electric Buildings—Added.
Sections 4.106.5, 4.106.5.1, and 4.106.5.2 are added to read:
4.106.5 All-electric buildings. New construction buildings and qualifying alteration projects shall comply with Section 4.106.5.1 or 4.106.5.2 so that they do not use combustion equipment or are ready to accommodate installation of electric heating appliances.
4.106.5.1. New construction and qualifying alteration projects. All newly constructed buildings shall be all-electric buildings. Qualifying alteration projects shall be limited to additions or alterations that remove 50 percent or more of the existing exterior walls of a dwelling and additions that increase the square footage of the structure by more than 50 percent.
The final determination whether a project meets the definition of a qualifying alteration project shall be made by the Building Official.
Exception:
If the applicant establishes that there is not an all-electric prescriptive compliance pathway for the building under the California Building Energy Efficiency Standards, and that the building is not able to achieve the performance compliance standard applicable to the building under the Energy Efficiency Standards using commercially available technology and an approved calculation method, then the Building Official may grant a modification. The applicant shall comply with the following and Section 4.106.5.2.
Inactive Fuel Gas Infrastructure may be extended to spaces that are anticipated to qualify for the exceptions contained in this chapter. The inactive Fuel Gas Infrastructure shall not be activated, have a meter installed, or otherwise used unless the exemptions specified in this chapter have been confirmed as part of the issuance of a building permit. If the Fuel Gas Infrastructure is no longer serving one of the exceptions contained in this chapter, it shall either be capped, otherwise terminated, or removed by the entity previously entitled to the exemption, in a manner pursuant to all applicable Codes.
The Building Official shall have the authority to approve alternative materials and methods of construction as per the Dublin Municipal Code, Chapter 7.28.
4.106.5.2 Requirements for combustion equipment.
Where combustion equipment is allowed under subsection 4.106.5.1, the construction drawings shall indicate electrical infrastructure and physical space accommodating the future installation of an electrical heating appliance in the following ways, as certified by a registered design professional or licensed electrical contractor:
1. Branch circuit wiring, electrically isolated and designed to serve all electrical heating appliances in accordance with manufacturer requirements and the California Electrical Code, including the appropriate voltage, phase, minimum amperage, and an electrical receptacle or junction box within five feet of the appliance that is accessible with no obstructions. Appropriately sized conduit may be installed in lieu of conductors; and
2. Labeling of both ends of the unused conductors or conduit shall be with “For Future Electrical Appliance”; and
3. Reserved circuit breakers in the electrical panel for each branch circuit, appropriately labeled (i.e. “Reserved for Future Electric Range”), and positioned on the opposite end of the panel supply conductor connection; and
4. Connected subpanels, panelboards, switchboards, busbars, and transformers shall be sized to serve the future electrical heating appliances. The electrical capacity requirements shall be adjusted for demand factors in accordance with the California Electric Code; and
5. Physical space for future electrical heating appliances, including equipment footprint, and if needed a pathway reserved for routing of ductwork to heat pump evaporator(s), shall be depicted on the construction drawings. The footprint necessary for future electrical heating appliances may overlap with non-structural partitions and with the location of currently designed combustion equipment.
(Ord. 13-22 § 13 (Exh. L))
7.94.080 Section 4.107.1, Division 4.1, Chapter 4, Future access for solar systems—Added.
A new Section 4.107.1 is added to read:
4.107.1 Future Access for Solar Systems. A minimum one-inch (25.4 mm) electrical conduit shall be provided from the electrical service equipment to the solar zone as defined by the California Energy Code, Title 24, Part 6, Section 110.10. Where a solar zone is not required by the California Energy Code, the conduit location shall be subject to approval of the Building Official.
Exception: Where solar is installed as part of the original construction and prior to first occupancy.
(Ord. 13-22 § 13 (Exh. L))
7.94.085 Section 4.420, Division 4.4, Chapter 4, Low Carbon Concrete—Added.
A new Section 4.420 is added to read:
4.420 Low Carbon Concrete Requirements.
4.420.1 Purpose. The purpose of this section is to provide standards and requirements for the composition of concrete, as defined herein, that maintains adequate strength and durability for the intended application and at the same time reduces greenhouse gas emissions associated with concrete composition.
4.420.1.2 Applicability. The requirements of this section shall only be applicable to projects that require a building permit.
4.420.3 Compliance. Compliance with the requirements of this section shall be demonstrated through any of the compliance options in Sections 4.420.3.2 through 4.420.3.5.
|
|
Cement limits for use with any compliance method 4.420.3.2 through 4.420.3.5 |
Embodied carbon limits for use with any compliance method 4.420.3.2 through 4.420.3.5 |
|---|---|---|
|
Minimum specified compressive strength f’c, psi |
Maximum ordinary Portland cement content, lbs/yd3 (1) |
Maximum embodied carbon kg CO2e/m3, per Environmental Product Declaration |
|
up to 2500 |
362 |
260 |
|
2501-3000 |
410 |
289 |
|
3001-4000 |
456 |
313 |
|
4001-5000 |
503 |
338 |
|
5001-6000 |
531 |
356 |
|
6001-7000 |
594 |
394 |
|
Greater than 7000 |
657 |
433 |
|
up to 3000 light weight |
512 |
578 |
|
Up to 4000 light weight |
571 |
626 |
|
4001-5000 light weight |
629 |
675 |
|
Notes (1) Portland cement of any type per ASTM C150. |
||
4.420.3.1 Allowable Increases
(1) Approved Cements. The maximum cement content may be increased proportionately above the tabulated value when using an approved cement, or blended cement, demonstrated by approved Environmental Product Declaration to have a plant-specific Environmental Product Declaration lower than 1040 kg CO2e/metric ton. The increase in allowable cement content is:
1040/plant-specific Environmental Product Declaration %.
(2) Cement and Embodied Carbon Limit Allowances. Cement or Embodied Carbon limits shown in Table 4.420.3 can be increased by 30% for concretes demonstrated to the Building Official as requiring high early strength. Such concretes may include but are not limited to, precast or prestressed concrete; beams and slabs above grade; and shotcrete.
4.420.3.2 Cement Limit Method – Mix
Cement content of a concrete mix using this method shall not exceed the value shown in Table 4.420.3. Use of this method is limited to concrete with specified compressive strength not exceeding 5,000 psi.
4.420.3.3. Cement Limit Method – Project
Total cement content shall be based on total cement usage of all concrete mix designs within the same project. Total cement content for a project shall not exceed the value calculated according to Equation 4.420.3.3.
Equation 4.420.3.3:
Σ(Cemn)(vn) ≤ Σ(Cemlim)(vn)
Where,
n = the total number of concrete mixtures for the project
Cemn = the cement content for mixture n, kg/m3 or lb/yd3
Cemlim = the maximum cement content for mixture n per Table 4.420.3, kg/m3 or lb/yd3
vn = the volume of mixture n concrete to be placed, yd3 or m3
Calculations may use yd3 or m3 but must keep the same units throughout.
4.420.3.4 Embodied Carbon Method – Mix
Mix embodied carbon of a concrete mix, based on an approved Environmental Product Declaration, shall not exceed the value given in Table 4.420.3.
4.420.3.5 Embodied Carbon Method – Project
Total embodied carbon of all concrete mix designs within the same project (EC proj) shall not exceed the project limit (EC allowed) determined using Table 4.420.3 and Equation 4.420.3.5.
Equation 4.420.3.5:
Σ(ECn)(vn) ≤ Σ(EClim)(vn)
Where,
n = the total number of concrete mixtures for the project
ECn = the embodied carbon content for mixture n, per mixture Environmental Product Declaration, kgCO2e/m3
EClim = the maximum embodied carbon content for mixture n per Table 4.420.3, kgCO2e/m3
vn = the volume of mixture n concrete to be placed, yd3 or m3
4.420.3.6 Verification and Enforcement
Prior to the approval of the building permit application involving the placement of concrete, the permit applicant shall submit a completed Low-Carbon Concrete Compliance Form to the Building and Safety Division. If the permit applicant has not secured a concrete supplier at the time the permit application is submitted, the applicant may complete the Low-Carbon Concrete Compliance Form to calculate the maximum allowable cement and embodied carbon and shall certify by signature that they will meet maximum allowable limits at the time of construction.
As a condition of such building permits, and prior to approving construction inspections and prior to placement of concrete, the permit applicant shall submit batch certificates and/or Environmental Product Declarations with an updated Low-Carbon Concrete Compliance Form to the Building and Safety Division. The batch certificates and/or Environmental Product Declarations, and the updated Low-Carbon Concrete Compliance Form shall be reviewed for compliance by the Building and Safety Division prior to performing further inspections or pouring concrete.
When deviations from compliance with this section occur, the Building Official or their designee, is authorized to require the permit applicant to provide evidence of equivalent carbon reductions from the portions of remaining construction of the project to demonstrate alternative compliance with the intent of this chapter and payment of associated administrative fees. If the permit applicant is unable to provide evidence of equivalent carbon reductions, the Building & Safety Division reserves the right to penalize the permit applicant for the excess embodied carbon used in the project. Excess embodied carbon shall be determined by the amount of embodied carbon content in the project greater than EClim per Equation 4.420.3.5, in metric tons. The maximum penalty shall be determined as follows:
Pm = (ECx)($190) + A
Where,
Pm = the maximum penalty ($)
ECx = the total excess embodied carbon content in the project, in metric tons determined from Equation 4.420.3.5.
$190 = penalty per metric ton of excess embodied carbon ($/metric ton)
A = Building and Safety Administrative Fee ($), refer to the City’s Master Fee Schedule.
For projects involving placement of concrete by, or on behalf of, the City of Dublin the City Project Manager for the project, or their designee, shall maintain accurate records of the total volume (in cubic yards) of all concrete placed, as well as the total compliant volume (in cubic yards) of all concrete placed.
4.420.3.7 Exemptions
(a) Projects exempt from permits. Projects that do not require a building permit per Chapter 7.28, shall not be subject to the requirements in Section 4.420.
(b) Projects that do not involve the placement of ready-mix concrete.
(c) Asphaltic concrete is not considered as concrete for the purposes of Section 4.420.
(d) Due to lack of commercial availability of low-carbon concrete options, shotcrete, gunite, and stucco are exempt from embodied carbon requirements.
(e) Small projects as approved by the Building Official.
(f) Hardship or infeasibility exemption. If an applicant for a project subject to Section 4.420 believes that circumstances exist that make it a hardship or infeasible to meet the requirements of Section 4.420, the applicant may request an exemption as set forth below. In applying for an exemption, the burden is on the applicant to show hardship or infeasibility. The applicant shall identify in writing the specific requirements of the standards for compliance that the project is unable to achieve and the circumstances that make it a hardship or infeasible for the project to comply with this chapter. Circumstances that constitute hardship or infeasibility may include, but are not limited to the following:
(1) There is a lack of commercially available material necessary to comply with Section 4.420;
(2) The cost of achieving compliance is disproportionate to the overall cost of the project;
(3) Compliance with the requirements would impair the historic integrity of buildings listed on a local, state or federal list or register of historic structures as regulated by the California Historic Building Code (Title 24, Part 8).
(g) Granting of an exemption. If the Building Official determines that it is a hardship or infeasible for the applicant to fully meet the requirements of Section 4.420 and that granting the requested exemption will not cause the building to fail to comply with the California Green Building Standards Code, the Building Official shall determine the maximum feasible threshold of compliance reasonably achievable for the project. In making this determination, the Building Official shall consider whether alternate, practical means of achieving the objectives of Section 4.420 can be satisfied. If an exemption is granted, the applicant shall be required to comply with Section 4.420 in all other respects and shall be required to achieve the threshold of compliance determined to be achievable by the Building Official.
(h) Denial of exception. If the Building Official determines that it is reasonably possible for the applicant to fully meet the requirements of Section 4.420, the request shall be denied, and the applicant shall be notified of the decision in writing within 60 days after receipt of the request for exemption. The project and compliance documentation shall be modified to comply with the standards for compliance.
(Ord. 9-24 § 9)
7.94.090 Sections 5.106.5.3 and 5.106.5.3.1 Electric vehicle (EV) charging—Deleted and replaced.
Sections 5.106.5.3 and 5.106.5.3.1 are deleted and replaced with Section A5.106.5.3 to read:
Section A5.106.5.3 Electric vehicle (EV) charging for new construction is adopted as mandatory at the Tier 2 level.
(Ord. 13-22 § 13 (Exh. L))
7.94.100 Section 5.106.13, 5.106.13.1 and 5.106.13.2 All electric buildings—Added.
Section 5.106.13, 5.106.13.1 and 5.106.13.2 are added to read:
5.106.13 All-electric buildings. New construction buildings and qualifying alteration projects shall comply with Section 5.106.13.1 or 5.106.13.2 so that they do not use combustion equipment or are ready to facilitate future electrification.
5.106.13.1. New construction and qualifying alteration projects. All newly constructed buildings shall be all-electric buildings. Qualifying alteration projects shall be limited to additions or alterations that remove 50 percent or more of the existing exterior walls of a structure and additions that increase the square footage of the structure by more than 50 percent.
Tenant improvements shall not be considered new construction. The final determination whether a project meets the definition of qualifying alteration project shall be made by the Building Official.
Exceptions:
1. Nonresidential buildings containing kitchens located in a place of public accommodation, as defined in the California Building Code Chapter 2, may apply to the Building Official for a modification to install commercial food heat-processing equipment served by fuel gas. The Building Official may grant the modification, provided the following findings are made:
a) The applicant has a business-related need to cook with combustion equipment; and
b) The applicant has installed energy efficient equipment based on Energy Star or California Energy Wise qualifications, as available.
c) The applicant will comply with Section 5.106.13.2.
2. If the applicant establishes that there is not an all-electric prescriptive compliance pathway for the building under the California Building Energy Efficiency Standards, and that the building is not able to achieve the performance compliance standard applicable to the building under the Energy Efficiency Standards using commercially available technology and an approved calculation method, then the Building Official may grant a modification. The applicant shall comply with following and Section 5.106.13.2:
Inactive Fuel Gas Infrastructure may be extended to spaces that are anticipated to qualify for the exceptions contained in this chapter. The inactive Fuel Gas Infrastructure shall not be activated, have a meter installed, or otherwise be used unless the exemptions specified in this chapter have been confirmed as part of the issuance of a building permit. If the Fuel Gas Infrastructure is no longer serving one of the exceptions contained in this chapter, it shall either be capped, otherwise terminated, or removed by the entity previously entitled to the exemption, in a manner pursuant to all applicable Codes.
The Building Official shall have the authority to approve alternative materials and methods of construction as per the Dublin Municipal Code, Chapter 7.28.
5.106.13.2. Requirements for combustion equipment.
Where combustion equipment is allowed under Subsection 5.106.13.1, the construction drawings shall indicate electrical infrastructure and physical space accommodating the future installation of an electrical heating appliance in the following ways, as certified by a registered design professional or licensed electrical contractor:
1. Branch circuit wiring, electrically isolated and designed to serve all electrical heating appliances in accordance with manufacturer requirements and the California Electrical Code, including the appropriate voltage, phase, minimum amperage, and an electrical receptacle or junction box within five feet of the appliance that is accessible with no obstructions. Appropriately sized conduit may be installed in lieu of conductors; and
2. Labeling of both ends of the unused conductors or conduit shall be with “For Future Electrical Appliance”; and
3. Reserved circuit breakers in the electrical panel for each branch circuit, appropriately labeled (i.e. “Reserved for Future Electric Range”), and positioned on the opposite end of the panel supply conductor connection; and
4. Connected subpanels, panelboards, switchboards, busbars, and transformers shall be sized to serve the future electrical heating appliances. The electrical capacity requirements shall be adjusted for demand factors in accordance with the California Electric Code; and
5. Physical space for future electrical heating appliances, including equipment footprint, and if needed a pathway reserved for routing of ductwork to heat pump evaporator(s), shall be depicted on the construction drawings. The footprint necessary for future electrical heating appliances may overlap with non-structural partitions and with the location of currently designed combustion equipment.
(Ord. 13-22 § 13 (Exh. L))
7.94.110 Section 5.107.1, Division 5.1, Chapter 5, Future access for solar systems—Added.
A new Section 5.107.1 is added to read:
5.107.1 Future Access for Solar Systems. Install conduit from the solar zone as defined by the California Energy Code, Title 24, Part 6, Section 110.10 to a location within the building identified as suitable for future installation of a charge controller (regulator) and inverter.
Exception: Where solar is installed as part of the original construction and prior to first occupancy.
(Ord. 13-22 § 13 (Exh. L))
7.94.120 Section 5.420, Division 5.4, Chapter 5, Low Carbon Concrete—Added.
A new Section 5.420 is added to read:
5.420 Low Carbon Concrete Requirements
5.420.1 Purpose. The purpose of this section is to provide standards and requirements for the composition of concrete, as defined herein, that maintains adequate strength and durability for the intended application and at the same time reduces greenhouse gas emissions associated with concrete composition.
5.420.1.2 Applicability. The requirements of this section shall only be applicable to projects that require a building permit.
5.420.3 Compliance. Compliance with the requirements of this section shall be demonstrated through any of the compliance options in Sections 5.420.3.2 through 5.420.3.5.
|
|
Cement limits for use with any compliance method 5.420.3.2 through 5.420.3.5 |
Embodied Carbon limits for use with any compliance method 5.420.3.2 through 5.420.3.5 |
|---|---|---|
|
Minimum specified compressive strength f’c, psi |
Maximum ordinary Portland cement content, lbs/yd3 (1) |
Maximum embodied carbon kg CO2e/m3, per Environmental Product Declaration |
|
up to 2500 |
362 |
260 |
|
2501-3000 |
410 |
289 |
|
3001-4000 |
456 |
313 |
|
4001-5000 |
503 |
338 |
|
5001-6000 |
531 |
356 |
|
6001-7000 |
594 |
394 |
|
Greater than 7000 |
657 |
433 |
|
up to 3000 light weight |
512 |
578 |
|
Up to 4000 light weight |
571 |
626 |
|
4001-5000 light weight |
629 |
675 |
|
Notes (1) Portland cement of any type per ASTM C150. |
||
5.420.3.1 Allowable Increases
(1) Approved Cements. The maximum cement content may be increased proportionately above the tabulated value when using an approved cement, or blended cement, demonstrated by approved Environmental Product Declaration to have a plant-specific Environmental Product Declaration lower than 1040 kg CO2e/metric ton. The increase in allowable cement content is:
1040/plant-specific Environmental Product Declaration %.
(2) Cement and Embodied Carbon Limit Allowances. Cement or Embodied Carbon limits shown in Table 5.420.3 can be increased by 30% for concretes demonstrated to the Building Official as requiring high early strength. Such concretes may include but are not limited to, precast or prestressed concrete; beams and slabs above grade; and shotcrete.
5.420.3.2 Cement Limit Method – Mix
Cement content of a concrete mix using this method shall not exceed the value shown in Table 5.420.3. Use of this method is limited to concrete with specified compressive strength not exceeding 5,000 psi.
5.420.3.3. Cement Limit Method – Project
Total cement content shall be based on total cement usage of all concrete mix designs within the same project. Total cement content for a project shall not exceed the value calculated according to Equation 5.420.3.3.
Equation 5.420.3.3:
Σ(Cemn)(vn) ≤ Σ(Cemlim)(vn)
Where,
n = the total number of concrete mixtures for the project
Cemn = the cement content for mixture n, kg/m3 or lb/yd3
Cemlim = the maximum cement content for mixture n per Table 5.420.3, kg/m3 or lb/yd3
vn = the volume of mixture n concrete to be placed, yd3 or m3
Calculations may use yd3 or m3 but must keep the same units throughout.
5.420.3.4 Embodied Carbon Method – Mix
Mix embodied carbon of a concrete mix, based on an approved Environmental Product Declaration, shall not exceed the value given in Table 5.420.3.
5.420.3.5 Embodied Carbon Method – Project
Total embodied carbon of all concrete mix designs within the same project (EC proj) shall not exceed the project limit (EC allowed) determined using Table 5.420.3 and Equation 5.420.3.5.
Equation 5.420.3.5:
Σ(ECn)(vn) ≤ Σ(EClim)(vn)
Where,
n = the total number of concrete mixtures for the project
ECn = the embodied carbon content for mixture n, per mixture Environmental Product Declaration, kgCO2e/m3
EClim = the maximum embodied carbon content for mixture n per Table 4.420.3, kgCO2e/m3
vn = the volume of mixture n concrete to be placed, yd3 or m3
5.420.3.6 Verification and Enforcement
Prior to the approval of the building permit application involving the placement of concrete, the permit applicant shall submit a completed Low-Carbon Concrete Compliance Form to the Building and Safety Division. If the permit applicant has not secured a concrete supplier at the time the permit application is submitted, the applicant may complete the Low-Carbon Concrete Compliance Form to calculate the maximum allowable cement and embodied carbon and shall certify by signature that they will meet maximum allowable limits at the time of construction.
As a condition of such building permits, and prior to approving construction inspections and prior to placement of concrete, the permit applicant shall submit batch certificates and/or Environmental Product Declarations with an updated Low-Carbon Concrete Compliance Form to the Building and Safety Division. The batch certificates and/or Environmental Product Declarations, and the updated Low-Carbon Concrete Compliance Form shall be reviewed for compliance by the Building and Safety Division prior to performing further inspections or pouring concrete.
When deviations from compliance with this section occur, the Building Official or their designee is authorized to require the permit applicant to provide evidence of equivalent carbon reductions from the portions of remaining construction of the project to demonstrate alternative compliance with the intent of this chapter and payment of associated administrative fees. If the permit applicant is unable to provide evidence of equivalent carbon reductions, the Building and Safety Division reserves the right to penalize the permit applicant for the excess embodied carbon used in the project. Excess embodied carbon shall be determined by the amount of embodied carbon content in the project greater than EClim per Equation 4.420.3.5, in metric tons. The maximum penalty shall be determined as follows:
Pm = (ECx)($190) + A
Where,
Pm = the maximum penalty ($)
ECx = the total excess embodied carbon content in the project, in metric tons determined from Equation 4.420.3.5.
$190 = penalty per metric ton of excess embodied carbon ($/metric ton)
A = Building and Safety Administrative Fee ($), refer to the City’s Master Fee Schedule.
For projects involving placement of concrete by, or on behalf of, the City of Dublin the City Project Manager for the project, or their designee, shall maintain accurate records of the total volume (in cubic yards) of all concrete placed, as well as the total compliant volume (in cubic yards) of all concrete placed.
5.420.3.7 Exemptions
(a) Projects exempt from permits. Projects that do not require a building permit per Chapter 7.28, shall not be subject to the requirements in section 5.420.
(b) Projects that do not involve the placement of ready-mix concrete.
(c) Asphaltic concrete is not considered as concrete for the purposes of section 5.420.
(d) Due to lack of commercial availability of low-carbon concrete options, shotcrete, gunite, and stucco are exempt from embodied carbon requirements.
(e) Small projects as approved by the Building Official.
(f) Hardship or infeasibility exemption. If an applicant for a project subject to Section 5.420 believes that circumstances exist that make it a hardship or infeasible to meet the requirements of Section 5.420, the applicant may request an exemption as set forth below. In applying for an exemption, the burden is on the applicant to show hardship or infeasibility. The applicant shall identify in writing the specific requirements of the standards for compliance that the project is unable to achieve and the circumstances that make it a hardship or infeasible for the project to comply with this chapter. Circumstances that constitute hardship or infeasibility may include, but are not limited to the following:
(1) There is a lack of commercially available material necessary to comply with Section 5.420;
(2) The cost of achieving compliance is disproportionate to the overall cost of the project;
(3) Compliance with the requirements would impair the historic integrity of buildings listed on a local, state, or federal list or register of historic structures as regulated by the California Historic Building Code (Title 24, Part 8).
(g) Granting of an exemption. If the Building Official determines that it is a hardship or infeasible for the applicant to fully meet the requirements of Section 5.420 and that granting the requested exemption will not cause the building to fail to comply with the California Green Building Standards Code, the Building Official shall determine the maximum feasible threshold of compliance reasonably achievable for the project. In making this determination, the Building Official shall consider whether alternate, practical means of achieving the objectives of Section 5.420 can be satisfied. If an exemption is granted, the applicant shall be required to comply with Section 5.420 in all other respects and shall be required to achieve the threshold of compliance determined to be achievable by the Building Official.
(h) Denial of exception. If the Building Official determines that it is reasonably possible for the applicant to fully meet the requirements of Section 5.420, the request shall be denied, and the applicant shall be notified of the decision in writing within 60 days after receipt of the request for exemption. The project and compliance documentation shall be modified to comply with the standards for compliance.
(Ord. 9-24 § 10)