HomeMy WebLinkAbout5.6 Ordinance Adding a Low Carbon Concrete Requirement to the City’s Green Building Code in Coordination with the City’s Climate Action Planr
DUBLIN
CALIFORNIA
STAFF REPORT
CITY COUNCIL
Agenda Item 5.6
DATE: September 17, 2024
TO: Honorable Mayor and City Councilmembers
FROM: Linda Smith, City Manager
SU B.ECT : Ordinance Adding a Low Carbon Concrete Requirement to the City's Green
Building Code in Coordination with the City's Climate Action Plan
Prepared by: Nelson Pureco, Plan Check Engineer, and Shannan Young,
Environmental & Sustainability Manager
EXECUTIVE SUMMARY:
The City Council will consider waiving the second reading and adopting the Ordinance amending
the Dublin Municipal Code Chapter 7.94 (Green Building Code) to Amend Section 7.94.050
(Definitions) and to Add Section 7.94.085 (Low Carbon Concrete) and Section 7.94.120 (Low
Carbon Concrete). The City Council waived the first reading and introduced the ordinance at the
meeting on September 3, 2024.
STAFF RECOMMENDATION:
Waive the second reading and adopt the Ordinance Approving Amendments to the Dublin
Municipal Code Chapter 7.94 (Green Building Code) to Amend Section 7.94.050 (Definitions) and
to Add Section 7.94.085 (Low Carbon Concrete) and Section 7.94.120 (Low Carbon Concrete).
FINANCIAL IMPACT:
The cost associated with implementing the Ordinance is estimated to be approximately $85,000 to
$140,000 per year, reflecting staff time to educate applicants on the Ordinance and additional plan
check and inspection time commitments. The City will recover the costs via fees adopted in the
Master Fee Schedule.
Page 1 of 2
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DESCRIPTION:
The City of Dublin adopted the Climate Action Plan 2030 and Beyond (CAP 2030) on September
15, 2020 (Resolution 100-20). CAP 2030 includes five strategies with 22 measures intended to
reduce greenhouse gas emissions by 40 percent below 1990 levels by 2030 and to put the City on
the path to reach carbon neutrality by 2045.
Included under Strategy 4 is Measure MM-2, Reduce the Embodied Greenhouse Gas Emissions
(GHG) Associated with Building Materials. The embodied GHG emissions of a building are carbon
dioxide or other GHGs generated by making and transporting building materials to a site,
including mining, refining, and shipping. According to the Rocky Mountain Institute, 11 percent of
global GHG emissions are generated during the lifecycle of building materials and concrete
production is responsible for approximately 8 percent of global carbon emissions. The GHG
emissions associated with concrete can be reduced by minimizing cement use to the extent
possible or by using cement alternatives called supplementary cementitious materials (SCMs).
SCMs include but are not limited to fly ash, slag, and glass pozzolans.
On September 3, 2024, the City Council held a public hearing and introduced an Ordinance
amending the Dublin Municipal Code Chapter 7.94 (Green Building Code) to require the use of low
carbon concrete. The Ordinance would amend Section 7.94.050 (Definitions) and add Section
7.94.085 (Low Carbon Concrete) and Section 7.94.120 (Low Carbon Concrete) (Ordinance). These
requirements would be applicable to all projects that require a building permit and that use ready -
mix concrete, and this requirement would go into effect on January 1, 2025.
The City Council will consider waiving the second reading and adopting the Ordinance
(Attachment 1) approving amendments to the DMC Green Building Code. Attachment 2 provides a
complete description of the proposed Ordinance.
STRATEGIC PLAN INITIATIVE:
None.
NOTICING REQUIREMENTS/PUBLIC OUTREACH:
The City Council Agenda was posted.
ATTACHMENTS:
1) Ordinance Approving Amendments to the Dublin Municipal Code Chapter 7.94 (Green Building
Code) to Amend Section 7.94.050 (Definitions) and to Add Section 7.94.085 (Low Carbon
Concrete) and 7.94.120 (Low Carbon Concrete)
2) September 3, 2024 Staff Report (without attachments)
Page 2 of 2
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Attachment I
ORDINANCE NO. xx — 24
AN ORDINANCE OF THE CITY COUNCIL
OF THE CITY OF DUBLIN
APPROVING AMENDMENTS TO THE DUBLIN MUNICIPAL CODE CHAPTER 7.94 (GREEN
BUILDING CODE) TO AMEND SECTION 7.94.050 (DEFINITIONS) AND TO ADD SECTION
7.94.085 (LOW CARBON CONCRETE) AND SECTION 7.94.120 (LOW CARBON
CONCRETE)
The Dublin City Council does ordain as follows:
SECTION 1. RECITALS.
A. Health and Safety Code Section 18938 makes provisions published in the California Building
Standards Code pursuant to Health and Safety Code Section 17922 applicable to all
occupancies throughout the State and effective one hundred and eighty days after publication
by the California Building Standards Commission (the "Commission"), or at a later date
established by the Commission.
B. California Health and Safety Code Sections 17958, 17958.5, 17958.7 and 18941.5 establish
the authority for a city to adopt and make local amendments and modifications to the building
standards in the California Building Standards Code to establish more restrictive building
standards than those contained in the California Building Standards Code.
C. California Health and Safety Code Sections 17958, 17958.5, 17958.7 and 18941.5 permit a
city to make such local amendments and modifications as the city determines are reasonably
necessary because of local climatic, geological, or topographical conditions.
D. California Health and Safety Code Sections 17958, 17958.5, 17958.7 and 18941.5 require a
city, before making any amendments and modifications to the California Building Standards
Code, make an express finding that such amendments and modifications are reasonably
necessary because of local climatic, geological, or topographical conditions.
E. Under Health and Safety Code Section 17958.7, changes pursuant to Health and Safety Code
Section 17958.5 may not become effective until the required findings, and the changes, have
been filed with the California Building Standards Commission; and
F. Government Code Section 50022.2 permits enactment of City Ordinances that adopt codes
or statutes, including codes of the State of California, by reference.
G. A Staff Report was submitted to the Dublin City Council recommending approval of the
proposed amendments to Dublin Municipal Code Chapter 7.94 (Green Building Code).
H. The City Council held a public hearing on the proposed amendments to Dublin Municipal Code
Chapter 7.94 (Green Building Code) on September 3, 2024, at which time all interested
persons had an opportunity to be heard.
I. Proper notice of said hearing was given in all respects as required by law.
Ord. No. XX-24, Item X.X, Adopted XX/XX/24 Page 1 of 13
3
J. The City Council did hear and consider all said reports, recommendations and testimony herein
above set forth and used its independent judgement to evaluate the amendments.
Section 2. EFFECT OF CODE ON PAST ACTIONS AND OBLIGATIONS.
The adoption of the Dublin Building Code, 2022, does not affect any civil lawsuit instituted or filed
or prosecutions for ordinance violations committed on or prior to the effective date of said Code,
does not waive any fee or penalty due and unpaid prior to the effective date of said Code, and
does not affect the validity of any bond or cash deposit posted, filed or deposited pursuant to the
requirements of any ordinance.
Section 3. REFERENCES TO PRIOR CODE.
Unless superseded and expressly repealed, references in City forms, documents and regulations
to the chapters and sections of the former Dublin Building Code, 2019, shall be construed to apply
to the corresponding provisions contained within the Dublin Building Code, 2022.
Section 4. No penalty clauses are adopted by reference pursuant to this Ordinance. While
Chapter 7.94 of the Dublin Municipal Code remain in force, a reasonable supply of the
incorporated codes shall be available in the office of the City Clerk for public purchase.
Section 5. SEVERABILITY.
The provisions of this Ordinance are severable and if any provision, clause, sentence, word or
part thereof is held illegal, invalid, unconstitutional, or inapplicable to any person or circumstances,
such illegality, invalidity, unconstitutionality, or inapplicability shall not affect or impair any of the
remaining provisions, clauses, sentences, sections, words or parts thereof of the ordinance or
their applicability to other persons or circumstances.
Section 6. POSTING.
This Ordinance shall take effect on January 1, 2025. The City Clerk of the City of Dublin shall
cause this Ordinance to be posted in at least three (3) public places in the City of Dublin in
accordance with Government Code Section 36933.
Section 7. CEQA FINDING.
The City Council hereby finds that the adoption of this Ordinance is exempt from the California
Environmental Quality Act ("CEQA") pursuant to California Code of Regulations Title 14, sections
15002 and 15378 as this Ordinance is not a "project" within the meaning of the State CEQA
Guidelines. Specifically, this Ordinance will not result in a direct or reasonably foreseeable
indirect physical change in the environment because it does not authorize the construction of any
new large structures or other physical changes resulting in impacts to the environment.
Section 8. AMENDMENT 7.94.050 OF THE DUBLIN MUNICIPAL CODE.
Section 7.94.050 of the Dublin Municipal Code is hereby amended to read as follows:
7.94.050 Section 202, Chapter 2, Definitions — Amended.
Ord. No. XX-24, Item X.X, Adopted XX/XX/24 Page 2 of 13
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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.
Ord. No. XX-24, Item X.X, Adopted XX/XX/24 Page 3 of 13
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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 gasses 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 (SCM'S). 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 gasses, 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.
Section 9. ADDITION OF 7.94.085 TO THE DUBLIN MUNICIPAL CODE.
Section 7.94.085 is hereby added to the Dublin Municipal Code to read as follows:
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.
Ord. No. XX-24, Item X.X, Adopted XX/XX/24 Page 4 of 13
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Table 4.420.3: Cement and Embodied Carbon Limit Pathways
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, Ibs/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 Tight
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
Ord. No. XX-24, Item X.X, Adopted XX/XX/24 Page 5 of 13
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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:
Z(Cemn)(vn) < Z(Cemiim)(vn)
Where,
n = the total number of concrete mixtures for the project
Cemn = the cement content for mixture n, kg/m3 or lb/yd3
Cemiim = 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:
Z(ECn )(vn) <_ Z(ECiim )(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
ECiim = 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
Ord. No. XX-24, Item X.X, Adopted XX/XX/24 Page 6 of 13
8
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 & 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 & 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 & 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
ECiim 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
Ord. No. XX-24, Item X.X, Adopted XX/XX/24 Page 7 of 13
9
(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.
Section 10. ADDITION OF 7.94.120 TO THE DUBLIN MUNICIPAL CODE.
Section 7.94.120 is hereby added to the Dublin Municipal Code to read as follows:
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
Ord. No. XX-24, Item X.X, Adopted XX/XX/24 Page 8 of 13
10
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.
Table 5.420.3: Cement and Embodied Carbon Limit Pathways
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, Ibs/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 Tight
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 %.
Ord. No. XX-24, Item X.X, Adopted XX/XX/24 Page 9 of 13
11
(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:
Z(Cemn)(vn) < Z(Cemiim)(vn)
Where,
n = the total number of concrete mixtures for the project
Cemn = the cement content for mixture n, kg/m3 or lb/yd3
Cemiim = 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:
> (ECn )(vn) <_ I(ECiim )(vn )
Where,
n = the total number of concrete mixtures for the project
Ord. No. XX-24, Item X.X, Adopted XX/XX/24 Page 10 of 13
12
ECn = the embodied carbon content for mixture n, per mixture Environmental
Product Declaration, kgCO2e/m3
ECiim = 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 & 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 & 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 & 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
ECiim 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.
Ord. No. XX-24, Item X.X, Adopted XX/XX/24 Page 11 of 13
13
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.
{Signatures on the following page}
Ord. No. XX-24, Item X.X, Adopted XX/XX/24 Page 12 of 13
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PASSED AND ADOPTED BY the City Council of the City of Dublin on this 17th day of
September 2024, by the following votes:
AYES:
NOES:
ABSENT:
ABSTAIN:
Mayor
ATTEST:
City Clerk
Ord. No. XX-24, Item X.X, Adopted XX/XX/24 Page 13 of 13
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Attachment 2
II
DUBLIN
CALIFORNIA
STAFF REPORT
CITY COUNCIL
Agenda Item 6.1
DATE: September 3, 2024
TO: Honorable Mayor and City Councilmembers
FROM: Linda Smith, City Manager
SU B.ECT : Adding a Low Carbon Concrete Requirement to the City's Green Building
Code in Coordination with the City's Climate Action Plan
Prepared by: Nelson Pureco, Plan Check Engineer, and Shannan Young,
Environmental & Sustainability Manager
EXECUTIVE SUMMARY:
The City Council will consider introducing an ordinance amending the City's Green Building Code
to add a requirement for the use of low carbon concrete and adopting a related resolution. The
low carbon concrete requirements are in alignment with the City of Dublin Climate Action Plan
2030 and Beyond, Measure MM-2, Reduce the Embodied Greenhouse Gas Emissions Associated
with Building Materials.
STAFF RECOMMENDATION:
Take the following actions: 1) adopt the Resolution Approving Findings Regarding the Need for
Local Amendments to Provisions in the California Green Building Standards Code as Adopted by
the City; and 2) INTRODUCE the Ordinance Approving Amendments to the Dublin Municipal Code
Chapter 7.94 (Green Building Code) to Amend Section 7.94.050 (Definitions) and to Add Section
7.94.085 (Low Carbon Concrete) and Section 7.94.120 (Low Carbon Concrete).
FINANCIAL IMPACT:
The cost associated with implementing the Ordinance is estimated to be approximately $85,000 to
$140,000 per year for additional plan check and inspection time commitments. The costs may
decrease over time as applicants become familiar with the requirements. These increased costs
are accounted for in the City's Master Fee Schedule adopted in June 2024.
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DESCRIPTION:
Background
The City of Dublin adopted the Climate Action Plan 2030 and Beyond (CAP 2030) on September
15, 2020 (Resolution 100-20). CAP 2030 includes five strategies with 22 measures intended to
reduce greenhouse gas emissions by 40 percent below 1990 levels by 2030 and to put the City on
the path to reach carbon neutrality by 2045. The five strategies in CAP 2030 are:
Strategy 1 - Renewable and Carbon Free Electricity
Strategy 2 - Building Efficiency and Electrification
Strategy 3 - Sustainable Mobility and Land Use
Strategy 4 - Materials and Waste Management
Strategy 5 - Municipal Leadership
Included under Strategy 4 is Measure MM-2, Reduce the Embodied Greenhouse Gas Emissions
(GHG) Associated with Building Materials. The embodied GHG emissions of a building are carbon
dioxide or other GHGs generated by making and transporting building materials to a site,
including mining, refining, and shipping. According to the Rocky Mountain Institute', 11 percent of
global GHG emissions are generated during the lifecycle of building materials and concrete
production is responsible for approximately 8 percent of global carbon emissions. Although CAP
2030 did not quantify the embodied GHG emissions from the consumption of building materials,
the inclusion of Measure MM-2 acknowledges the importance of addressing embodied emission to
achieve the 2045 carbon neutrality goal.
Concrete is composed of an aggregate blend and cement. The GHG emissions associated with
concrete can be reduced by minimizing cement use to the extent possible or by using cement
alternatives called supplementary cementitious materials (SCMs). These include but are not
limited to fly ash, slag, and glass pozzolans. Based on conversations with local ready -mix suppliers,
Staff understands these cement alternatives to be locally available and have cost parity with
cement. These low carbon concrete mixes are not new. The State of California Department of
Transportation incorporated SCMs into the 2010 document "Guidelines for the Design &
Inspection of Concrete" and noted that SCMs are cost effective and provide benefits to the
strength, workability, permeability, and durability of concrete.
Based on Staff's research and in alignment with the goals of CAP 2030, Staff proposes to amend
the City's Green Building Code to add a requirement for the use of low carbon concrete.
Analysis
The proposed Ordinance would add Sections 7.94.085 and 7.94.120 to Chapter 7.94, Green
Building Code, of the Dublin Municipal Code (DMC).
The requirements are based on the low carbon concrete code adopted in 2019 by Marin County,
who partnered with several entities and conducted robust stakeholder engagement to develop a
1 The Rocky Mountain Institute is an independent, non -partisan, non-profit organization of experts across disciplines
working to accelerate the clean energy transition and improve lives.
Page 2 of 4
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regionally replicable building code amendment.
Requirements would be applicable to all projects that require a building permit and that use
ready -mix concrete. Projects that use bagged concrete, shotcrete, gunite, stucco, and asphaltic
concrete (asphalt) would be exempt. Projects would demonstrate compliance with the low carbon
concrete code by either using the cement limit equation or through the embodied carbon pathway.
When using the embodied carbon method, the carbon in the concrete mix shall not exceed the
values, as demonstrated via an Environmental Product Declaration (EPD) for the concrete mix. An
EPD is a document that provides third -party verification of life -cycle analysis of products and
goods.
If an applicant is unable to meet the limits, the applicant has the option to use an alternative
compliance pathway to demonstrate reduced equivalent carbon emissions reductions from the
remaining portions of the project. If the applicant is unable to provide sufficient evidence to
demonstrate equivalent carbon emissions reductions, the Ordinance allows for the assessment of
penalties based on the social cost of carbon as established by the United States Environmental
Protection Agency. The Ordinance includes the calculation for assessing penalties. The current
social cost of carbon is set at $190 per metric ton of carbon dioxide.
The initial implementation of the proposed Ordinance would be an education and outreach effort
led by the Public Works Department in conjunction with the Community Development
Department. To ensure a successful launch of the low carbon concrete code, Staff recommends
adoption with an effective date of January 1, 2025.
The proposed modifications as described in Section 7.94.085 and 7.94.120 are necessary to limit
carbon emissions associated with concrete construction, while ensuring adequate strength and
durability for the intended use. Low carbon concrete is available locally and can be incorporated
into projects occurring in the City. The reduction of greenhouse gas emissions from the use of low
carbon concrete helps mitigate climate change and its negative effects such as extreme heat,
droughts, intense storms, and flooding that may occur in the City, making these amendments
reasonably necessary for local climatic reasons.
In calendar year 2023, 2,903 building permits were issued. Of those permits, 11.6 percent (338
permits) would have been subject to this ordinance while 17.2 percent (499 permits) would
require further review to determine if the project met an exemption. Therefore, at least 71.2
percent of permits issued met an exception and would not require a review for compliance.
Based on the time it takes to review applications and enforce requirements during the plan check
and inspection process, Staff estimates that the new requirements will add 45 minutes to the
review time for smaller buildings, such as a single-family detached dwelling, to as much as four
hours for a large commercial project. Review and inspection times will likely decrease over time
as applicants, owners, contractors, and developers become more familiar with the standards.
The effect on residential projects depends on the scope of the project. See examples listed below:
• No Effect:
o Work that is exempt from a Building permit
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o Water heater replacement permits
o Heating and air conditioning replacement permits
o Electrical permits
• Possible Minor Effect:
o Repair work
o New swimming pool permits without a concrete deck around the pool
o Retaining walls
• Moderate Effect:
o New swimming pools with a concrete deck
o Small additions
o Accessory structures
o New landscaping permits with concrete pathways
• Full Effect:
o New buildings
o Accessory Dwellings Units
o Additions
Lastly, in order to amend our local Building Code, the City has to make certain legal findings that
support the amendments to the State Code. Attached to this item is a resolution that makes those
findings.
STRATEGIC PLAN INITIATIVE:
None.
NOTICING REQUIREMENTS/PUBLIC OUTREACH:
Two community meetings were held on April 10, 2024 to inform stakeholders of the potential
Ordinance and requirements. A combined 20 people attended, including both contractors and
developers. A few questions were addressed regarding the documentation and the timeframe of
the process.
In accordance with State law, a public notice was published in the East Bay Times and posted at
several locations throughout the City. The City Council Agenda was posted.
ATTACHMENTS:
1) Resolution Approving Findings Regarding the Need for Local Amendments to Provisions in the
California Green Building Standards Code as Adopted by the City
2) Exhibit A to the Resolution - California Green Building Standards Code Findings
3) Ordinance Approving Amendments to the Dublin Municipal Code Chapter 7.94 (Green Building
Code) to Amend Section 7.94.050 (Definitions) and to Add Section 7.94.085 (Low Carbon
Concrete) and Section 7.94.120 (Low Carbon Concrete)
4) Underline Version of the Proposed Amendments to Chapter 7.94 of the Dublin Municipal Code
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