Cambridge Apts (Low Income)
Multifamily Housing in Seattle, WA · 903 UNION ST · 98101
At a glance
Cambridge Apts (Low Income) is a 90,920-square-foot multifamily housing building at 903 UNION ST in Seattle, Washington, built in 1922. In its 2025 Seattle benchmarking disclosure it reported an ENERGY STAR score of 85 out of 100 (grade A), a site energy-use intensity of 61.4 kBtu/ft² and 209 tCO₂e of greenhouse-gas emissions. That score is higher than 38% of the 1,652 scored multifamily housing buildings in Seattle.
Seattle Energy Benchmarking Ordinance (SMC 22.920) · reporting year 2025
Benchmarking record
| Field | Value |
|---|---|
| ENERGY STAR score | 85 (band A) |
| Site EUI | 61.4 kBtu/ft² |
| Source EUI | 98.2 kBtu/ft² |
| GHG emissions | 209 tCO₂e |
| GHG intensity | 2.3 kgCO₂e/ft² |
| Electricity | 514,707 kWh |
| Natural gas | 38,237 therms |
| Gross floor area | 90,920 sq ft |
| Source record | seattle:21112:2025 |
The disclosure history
Year over year
| Year | Score | Δ | Site EUI | GHG emissions |
|---|---|---|---|---|
| 2025latest | 85 | -2 | 61.4 kBtu/ft² | 209 tCO₂e |
| 2024 | 87 | +5 | 58.4 kBtu/ft² | 196 tCO₂e |
| 2023 | 82 | +4 | 63.3 kBtu/ft² | 216 tCO₂e |
| 2022 | 78 | -3 | 69.3 kBtu/ft² | 244 tCO₂e |
| 2021 | 81 | -6 | 65.7 kBtu/ft² | 228 tCO₂e |
| 2020 | 87 | -1 | 56.1 kBtu/ft² | 213 tCO₂e |
| 2019 | 88 | -11 | 55.2 kBtu/ft² | 208 tCO₂e |
| 2018 | 99 | ±0 | 41.7 kBtu/ft² | 165 tCO₂e |
| 2017 | 99 | +4 | 47.7 kBtu/ft² | 212 tCO₂e |
| 2016 | 95 | +15 | 49.3 kBtu/ft² | 194 tCO₂e |
| 2015 | 80 | 64.7 kBtu/ft² | 266 tCO₂e |
Compliance context
Seattle Energy Benchmarking Ordinance (SMC 22.920)
Seattle's Building Emissions Performance Standard (adopted 2023) applies to buildings over 20,000 sq ft: benchmarking verification is due 2027–2030 and initial emissions targets 2031–2035, reaching net zero by 2041–2050, with fines for non-compliance.
Ownership
No owning organisation shown. Names of private individuals in the disclosure are not published here.
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Location
- Address
- 903 UNION ST
- City
- Seattle
- State
- Washington
- ZIP
- 98101
- Coordinates
- 47.61150, -122.32984
Within ~1 km
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See also: most efficient in Seattle · biggest emitters
How does Cambridge Apts (Low Income) compare with other multifamily housing buildings in Seattle?
The latest disclosures cover 1,971 multifamily housing buildings in Seattle, out of 3,871 buildings citywide. Cambridge Apts (Low Income)'s ENERGY STAR score of 85 compares with an average of 83 across the 1,652 that report a score; it scores higher than 38% of them and lower than 61%. Its site EUI of 61.4 kBtu/ft² is about 76% above the average of 34.9 kBtu/ft² — it uses more energy per square foot than the typical building in that group. Its emissions intensity of 2.3 kgCO₂e/ft² is about 229% above the group average of 0.7 kgCO₂e/ft².
At 90,920 sq ft, it is roughly in line with the average floor area of 86,468 sq ft for those buildings. It was built in 1922, 61 years earlier than the group's average year built (1983). Across all 24 jurisdictions BuildingCensus covers, the 59,945 multifamily housing buildings average an ENERGY STAR score of 70 and a site EUI of 59.0 kBtu/ft².
How has Cambridge Apts (Low Income)'s energy performance changed over time?
BuildingCensus holds 11 Seattle disclosures for Cambridge Apts (Low Income), covering report years 2015–2025. Its ENERGY STAR score went from 80 in 2015 to 85 in 2025 (+5 points); its best year on file was 2017, at 99. Site EUI moved from 64.7 kBtu/ft² (2015) to 61.4 kBtu/ft² (2025), a 5% decrease. Reported emissions went from 266 tCO₂e to 209 tCO₂e over the same span (down 22%).
What does an ENERGY STAR score of 85 mean?
ENERGY STAR scores run from 1 to 100 and are computed by the EPA's Portfolio Manager as a percentile against similar buildings nationwide, adjusted for climate, size and use: a score of 85 means the building performs better than about 85% of its national peers. BuildingCensus bands the score into report-card grades; 85 falls in band A — high performer (85–100). Scores of 75 or higher meet the threshold for ENERGY STAR certification; certification itself is a separate, verified application that the disclosure does not record. In Seattle, 69% of scored buildings are at 75 or above.
Site energy-use intensity (EUI) is the energy a building uses on site in a year divided by its floor area, in thousand Btu per square foot — lower is more efficient. Cambridge Apts (Low Income)'s 61.4 kBtu/ft² across 90,920 sq ft works out to about 5.6 billion Btu (1,636 MWh-equivalent) in 2025. Its source EUI of 98.2 kBtu/ft² also counts the energy lost generating and delivering that power, which is why it is higher. The disclosure also reports 514,707 kWh of electricity and 38,237 therms of natural gas for the year.
Which law requires Cambridge Apts (Low Income) to report its energy use?
Cambridge Apts (Low Income) reports under the Seattle Energy Benchmarking Ordinance (SMC 22.920), the legal basis of Seattle's Building Energy Benchmarking program, which publishes each covered building's annual benchmarking results. The record shown here is the report-year 2025 disclosure (source record seattle:21112:2025). Seattle's Building Emissions Performance Standard (adopted 2023) applies to buildings over 20,000 sq ft: benchmarking verification is due 2027–2030 and initial emissions targets 2031–2035, reaching net zero by 2041–2050, with fines for non-compliance.
More multifamily housing buildings in Seattle
- Sonata At Columbia Station· 90,759 sq ft · score 96 (A)
- Lakewest Condos - Flats· 90,372 sq ft · score 93 (A)
- Gainsborough Condominium· 90,000 sq ft · score 79 (B)
- Union Gospel Mission Assn / Hope Place· 89,821 sq ft · score 61 (C)
- Daystar Retirement Village· 89,549 sq ft · score 57 (C)
- Northline Apts· 89,068 sq ft · score 51 (D)
- Multifamily Housing buildings in Seattle· 1,971 benchmarked
- All Seattle benchmarked buildings· Seattle Energy Benchmarking Ordinance (SMC 22.920)
- Most efficient large buildings in Seattle
- Least efficient large buildings in Seattle
- Biggest emitters in Seattle
Frequently asked questions
What is Cambridge Apts (Low Income)'s energy grade?
Cambridge Apts (Low Income) scores 85 out of 100 on ENERGY STAR — band A, high performer (85–100) — in its 2025 Seattle disclosure. Scores are national percentiles against similar buildings; 75+ qualifies for ENERGY STAR certification.
How much energy does Cambridge Apts (Low Income) use?
Its 2025 site energy-use intensity was 61.4 kBtu/ft² (98.2 kBtu/ft² source) across 90,920 sq ft, including 514,707 kWh of electricity and 38,237 therms of natural gas.
What are Cambridge Apts (Low Income)'s carbon emissions?
Cambridge Apts (Low Income) reported 209 tCO₂e of greenhouse-gas emissions (2.3 kgCO₂e/ft²) for 2025.
Where is Cambridge Apts (Low Income)?
Cambridge Apts (Low Income) is at 903 UNION ST, in Seattle, Washington 98101. Its coordinates are 47.61150, -122.32984 (latitude, longitude), as published in the Building Energy Benchmarking file.
How big is Cambridge Apts (Low Income) and when was it built?
Cambridge Apts (Low Income) has 90,920 sq ft of gross floor area, as reported in its 2025 disclosure. The disclosure lists 1922 as its year built. It is classed as multifamily housing.
Is Cambridge Apts (Low Income) covered by the Seattle Energy Benchmarking Ordinance (SMC 22.920)?
Yes — it appears in the 2025 Building Energy Benchmarking disclosure, which lists the buildings reporting under the Seattle Energy Benchmarking Ordinance (SMC 22.920).
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About this data
Source: Building Energy Benchmarking (Seattle Energy Benchmarking Ordinance (SMC 22.920)), as published October 2, 2026. See the methodology for how records are matched, cleaned and scored.
Cite as: BuildingCensus, “Cambridge Apts (Low Income), Seattle, Washington — 2025 benchmarking disclosure”, https://buildingcensus.com/buildings/seattle/cambridge-apts-low-income-7029b73d (data as of October 2, 2026).