Embodied carbon/buildings

AN ACT Relating to reducing embodied carbon emissions of 1
buildings and building materials; adding new sections to chapter 2
19.27 RCW; and adding a new section to chapter 43.330 RCW.3
BE IT ENACTED BY THE LEGISLATURE OF THE STATE OF WASHINGTON:4
NEW SECTION. Sec. 1. A new section is added to chapter 19.27 5
RCW to read as follows: 6
(1) The state building code council shall adopt and amend rules 7
as necessary to accomplish the embodied carbon emissions reductions 8
required in section 8 of this act. In developing these standards, the 9
state building code council shall consult with the appropriate state 10
agencies, including the department of enterprise services, the 11
department of commerce, the department of ecology, the University of 12
Washington, an existing technical work group with relevant expertise, 13
and other interested parties. 14
(2) Except for school district construction, this act shall apply 15
to all new construction, additions, and renovations 100,000 square 16
feet or larger of any building covered by the international building 17
code. 18
(3) The state building code council may introduce further 19
criteria as building data is collected over time. 20
H-2736.1
HOUSE BILL 2273
State of Washington 69th Legislature 2026 Regular Session
By Representatives Duerr, Doglio, Berry, Reed, Parshley, Zahn,
Street, and Pollet
Prefiled 01/06/26. Read first time 01/12/26. Referred to Committee
on Local Government.
p. 1 HB 2273
(4) Projects covered under subsection (2) of this section may 1
choose one of the following three paths to comply with the embodied 2
carbon emissions reduction requirements: 3
(a) Maintaining an existing portion of a building structure and 4
envelope pursuant to section 2 of this act; 5
(b) Demonstrating a reduction in A1 to A3 life-cycle stage 6
emissions in covered products pursuant to section 3 of this act; and7
(c) Demonstrating embodied carbon emissions reduction using a 8
whole building life-cycle assessment pursuant to section 4 of this 9
act. 10
NEW SECTION. Sec. 2. A new section is added to chapter 19.27 11
RCW to read as follows: 12
(1) Building projects that maintain at least 45 percent of an 13
existing structure and envelope and do not add more than 50 percent 14
to the total area comply with the embodied carbon emissions 15
reductions requirements established in section 8 of this act.16
(2) The state building code council shall adopt rules to 17
determine how 45 percent reuse of an existing structure and envelope 18
will be calculated, such as by cost, mass, area, or volume. Hazardous 19
materials or assemblies that are not compliant with energy code 20
requirements are excluded from these calculations.21
NEW SECTION. Sec. 3. A new section is added to chapter 19.27 22
RCW to read as follows: 23
(1)(a) As an alternative to the requirements in section 2 or 4 of 24
this act, all building projects must demonstrate, and require in the 25
construction documents, that the life-cycle stage A1 through A3 26
embodied carbon emissions of the covered products used, measured in 27
terms of global warming potential for at least 90 percent of covered 28
products and summed up at the project level, meets the goals 29
established in section 8 of this act when compared to the project's 30
summed industry average global warming potential. To achieve this 31
reduction, building projects must use project-specific as-built 32
material quantities and product and facility-specific environmental 33
product declarations to demonstrate compliance. 34
(b) The state building code council shall adopt rules to define 35
covered products; determine how the 90 percent of covered products 36
shall be calculated, such as by cost, mass, or volume; and establish 37
how industry average will be determined . To make this determination, 38
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the state building code council will review and consider aligning 1
with established industry standards. 2
(c) A building project's design professional of record shall 3
update material quantities and embodied carbon emissions calculations 4
based on product and facility-specific environmental product 5
declarations from procured products and attest that they are accurate 6
and comply with the construction documents requirements to the best 7
of the design professional's knowledge, before substantial 8
completion. These calculations shall be verified as accurate within 9
the industry standard of care with a letter stamped by a design 10
professional of record. 11
(2) The state building code council shall create or designate a 12
template reporting form for consistent reporting on materials, 13
including guidance on calculating compliance with reduction targets.14
(3) The state building code council may include additional 15
covered materials. 16
NEW SECTION. Sec. 4. A new section is added to chapter 19.27 17
RCW to read as follows: 18
(1) As an alternative to the requirements in section 2 or 3 of 19
this act, building projects may demonstrate the embodied carbon 20
emissions reductions using a whole building life-cycle assessment as 21
compared against a functionally equivalent reference building. The 22
reference building shall be of the same size, geographic location, 23
function, and thermal performance as the proposed building, and shall 24
be functionally equivalent per ASTM E291-22. The materials and 25
material quantities in the proposed building and the reference 26
building may vary, provided that the buildings are functionally 27
equivalent. 28
(2) Whole building life-cycle assessments and any modeling 29
software used must comply with international standards. Tools used 30
for life-cycle assessment calculations must have the capability to 31
complete full cradle to grave analysis as defined by the 32
international organization for standardization standard 14044.33
(3) The state building code council shall adopt rules to require 34
compliance with a quantification standard for building life-cycle 35
greenhouse gas emissions. Alternatively, the state building code 36
council may adopt rules to specify required building element scope, 37
life-cycle stages, reference study periods, impact categories, 38
allowable data sources, biogenic carbon modeling and reporting 39
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guidance, material reuse and salvage reporting guidance, and at which 1
design stages the assessment should occur. The scope shall include, 2
at minimum, the covered products as defined by the building code 3
council. For buildings with a functional design life of less than 50 4
years, the project design and whole building life-cycle assessment 5
shall consider circular economy and building for disassembly 6
considerations for the primary building frame. 7
(4) The design professional of record responsible for the 8
embodied carbon calculations and reporting shall be specified in the 9
architect of record construction documents. The state building code 10
council shall provide a worksheet to be completed by project teams 11
for consistent reporting. The design professional of record shall 12
stamp an attestation that the designed building complies with this 13
section. The attestation shall be submitted along with the permit and 14
documents showing compliance. In addition, the design professional of 15
record shall supply as-built material quantities and environmental 16
product declaration for products installed on the project before 17
substantial completion. 18
NEW SECTION. Sec. 5. A new section is added to chapter 43.330 19
RCW to read as follows: 20
(1) All embodied carbon emissions reductions data must be entered 21
by the design professional of record on a standard form and public 22
database created and maintained by the department of commerce. At 23
minimum, the database must include basic information about the 24
project, project area, which compliance pathway was selected, 25
approximate location, primary structural system, primary building 26
use, and how the project met the standards for the selected pathway.27
(2) The department shall develop a public-facing website with 28
educational resources to support implementation. The website must:29
(a) Detail the embodied carbon emissions reductions requirements 30
in the state building code; 31
(b) Outline reporting requirements and guidelines;32
(c) Provide instructions for the use of the database;33
(d) Provide guidance for whole building life-cycle assessments;34
(e) Provide checklists, templates, training, and other tools as 35
needed to support implementation; and 36
(f) Provide a list of software that may be used to support 37
compliance with section 4 of this act. 38
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(2) The department shall conduct random audits on three percent 1
of projects annually. 2
NEW SECTION. Sec. 6. A new section is added to chapter 19.27 3
RCW to read as follows: 4
The definitions in this section apply throughout this chapter 5
unless the context clearly requires otherwise. 6
(1) "Design professional of record" means an architect or 7
engineer licensed pursuant to Title 18 RCW. 8
(2) "Embodied carbon emissions" means the amount of greenhouse 9
gas emissions associated with the extraction, manufacturing, 10
transport, installation, maintenance, and disposal of construction 11
products throughout the product's life. 12
(3) "Global warming potential" means the potential climate change 13
impact of a product or process as measured by a life-cycle 14
assessment. "Global warming potential" is the metric for tracking 15
embodied carbon emissions and is reported in units of carbon dioxide 16
equivalent. 17
(4) "Product and facility-specific environmental product 18
declarations" means a type III environmental product declaration, as 19
defined by the international organization for standardization 20
standard 14025, representing a single product from a single 21
manufacturing facility. 22
(5) "Whole building life-cycle assessment" means a cradle to 23
grave assessment covering life-cycle stages A-C as defined by the 24
international organization for standardization standard 21931-1, 25
excluding modules B6 and B7, or similarly robust whole building life-26
cycle assessment methods or whole life carbon assessment standards 27
that evaluate the environmental impacts of a building including, at a 28
minimum, global warming potential. 29
NEW SECTION. Sec. 7. A new section is added to chapter 19.27 30
RCW to read as follows: 31
The state building code council shall convene an existing 32
technical work group with relevant expertise established in RCW 33
19.27.033 for the purpose of recommending modifications and 34
limitations to the international building code adopted by Washington 35
regarding embodied carbon emissions reductions standards for 36
residential and nonresidential buildings. 37
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NEW SECTION. Sec. 8. A new section is added to chapter 19.27 1
RCW to read as follows: 2
(1) Except as provided in subsection (2) of this section, 3
construction permitted under the 2030 state building code must 4
achieve a 30 percent reduction in embodied carbon emissions from a 5
project-wide static baseline using the carbon leadership forum 2023 6
material baselines or comparable industry average data sources 7
determined by the state building code council, or achieve a 30 8
percent reduction in embodied carbon emissions compared to the 9
reference building as described in section 4 of this act.10
(2) The state building code council shall require product and 11
facility-specific environmental product declarations or whole 12
building life-cycle assessment results and project reporting for 13
covered products in the 2024 code cycle. If, before the 2027 code is 14
implemented, a product or facility-specific environmental product 15
declaration is not available, the applicable industry-regional 16
environmental product declaration must be required.17
(3) The state building code council shall adopt state building 18
codes in the 2027 and 2030 code cycles that incrementally move 19
towards achieving the 30 percent reduction in annual embodied carbon 20
emissions as specified in subsection (1) of this section. The state 21
building code council shall report its progress by December 31, 2028, 22
and every three years thereafter. The department of commerce shall 23
report major findings from the database of projects and audits 24
required in section 5 of this act conducted on the same timeline. 25
Audit findings will not result in penalties. 26
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