Lake Union House The Condominium
Multifamily Housing in Seattle, WA · 949 N 35TH ST · 98103
At a glance
Lake Union House The Condominium is a 23,101-square-foot multifamily housing building at 949 N 35TH ST in Seattle, Washington, built in 1978. In its 2025 Seattle benchmarking disclosure it reported an ENERGY STAR score of 82 out of 100 (grade B), a site energy-use intensity of 26.5 kBtu/ft² and 4 tCO₂e of greenhouse-gas emissions. That score is higher than 32% 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 | 82 (band B) |
| Site EUI | 26.5 kBtu/ft² |
| Source EUI | 74.2 kBtu/ft² |
| GHG emissions | 4 tCO₂e |
| GHG intensity | 0.1 kgCO₂e/ft² |
| Electricity | 179,502 kWh |
| Gross floor area | 23,101 sq ft |
| Source record | seattle:26479:2025 |
The disclosure history
Year over year
| Year | Score | Δ | Site EUI | GHG emissions |
|---|---|---|---|---|
| 2025latest | 82 | -1 | 26.5 kBtu/ft² | 4 tCO₂e |
| 2024 | 83 | +2 | 26.2 kBtu/ft² | 4 tCO₂e |
| 2023 | 81 | ±0 | 27.0 kBtu/ft² | 4 tCO₂e |
| 2022 | 81 | +3 | 27.8 kBtu/ft² | 4 tCO₂e |
| 2021 | 78 | +8 | 28.3 kBtu/ft² | 4 tCO₂e |
| 2020 | 70 | -12 | 29.0 kBtu/ft² | 4 tCO₂e |
| 2019 | 82 | +3 | 26.5 kBtu/ft² | 4 tCO₂e |
| 2018 | 79 | +4 | 26.8 kBtu/ft² | 4 tCO₂e |
| 2017 | 75 | +10 | 28.2 kBtu/ft² | 4 tCO₂e |
| 2016 | 65 | -5 | 28.0 kBtu/ft² | 4 tCO₂e |
| 2015 | 70 | 26.5 kBtu/ft² | 4 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.
Own or manage this building? Claim it to correct the record and get compliance alerts.
Location
- Address
- 949 N 35TH ST
- City
- Seattle
- State
- Washington
- ZIP
- 98103
- Coordinates
- 47.64955, -122.34545
Within ~1 km
Nearby benchmarked buildings
- Broadstone Vinscore 83
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- Bowman Stonewayscore 99
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- Parkview & Waterside Campusscore —
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- Tableau (North Edge)score 88
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- Adobe Building-801-N 34 St.score 74
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Office · 243,334 sq ft
See also: most efficient in Seattle · biggest emitters
How does Lake Union House The Condominium 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. Lake Union House The Condominium's ENERGY STAR score of 82 compares with an average of 83 across the 1,652 that report a score; it scores higher than 32% of them and lower than 66%. Its site EUI of 26.5 kBtu/ft² is about 24% below the average of 34.9 kBtu/ft² — it uses less energy per square foot than the typical building in that group. Its emissions intensity of 0.1 kgCO₂e/ft² is about 79% below the group average of 0.7 kgCO₂e/ft².
At 23,101 sq ft, it is about 73% below the average floor area of 86,468 sq ft for those buildings. It was built in 1978, 5 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 Lake Union House The Condominium's energy performance changed over time?
BuildingCensus holds 11 Seattle disclosures for Lake Union House The Condominium, covering report years 2015–2025. Its ENERGY STAR score went from 70 in 2015 to 82 in 2025 (+12 points); its best year on file was 2024, at 83. Site EUI moved from 26.5 kBtu/ft² (2015) to 26.5 kBtu/ft² (2025), an 0% increase. Reported emissions went from 4 tCO₂e to 4 tCO₂e over the same span (up 2%).
What does an ENERGY STAR score of 82 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 82 means the building performs better than about 82% of its national peers. BuildingCensus bands the score into report-card grades; 82 falls in band B — above median (70–84). 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. Lake Union House The Condominium's 26.5 kBtu/ft² across 23,101 sq ft works out to about 0.6 billion Btu (179 MWh-equivalent) in 2025. Its source EUI of 74.2 kBtu/ft² also counts the energy lost generating and delivering that power, which is why it is higher. The disclosure also reports 179,502 kWh of electricity for the year.
Which law requires Lake Union House The Condominium to report its energy use?
Lake Union House The Condominium 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:26479:2025). 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
- Dumar Apartments· 23,100 sq ft · score 95 (A)
- Allen Place Condominium· 23,098 sq ft · score 99 (A)
- Vega Apartments· 23,090 sq ft · score 92 (A)
- Queen Anne Flats· 23,060 sq ft · score 91 (A)
- Queen's Court Condo· 23,052 sq ft
- Queen Anne Exchange· 23,040 sq ft
- 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 Lake Union House The Condominium's energy grade?
Lake Union House The Condominium scores 82 out of 100 on ENERGY STAR — band B, above median (70–84) — in its 2025 Seattle disclosure. Scores are national percentiles against similar buildings; 75+ qualifies for ENERGY STAR certification.
How much energy does Lake Union House The Condominium use?
Its 2025 site energy-use intensity was 26.5 kBtu/ft² (74.2 kBtu/ft² source) across 23,101 sq ft, including 179,502 kWh of electricity.
What are Lake Union House The Condominium's carbon emissions?
Lake Union House The Condominium reported 4 tCO₂e of greenhouse-gas emissions (0.1 kgCO₂e/ft²) for 2025.
Where is Lake Union House The Condominium?
Lake Union House The Condominium is at 949 N 35TH ST, in Seattle, Washington 98103. Its coordinates are 47.64955, -122.34545 (latitude, longitude), as published in the Building Energy Benchmarking file.
How big is Lake Union House The Condominium and when was it built?
Lake Union House The Condominium has 23,101 sq ft of gross floor area, as reported in its 2025 disclosure. The disclosure lists 1978 as its year built. It is classed as multifamily housing.
Is Lake Union House The Condominium 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, “Lake Union House The Condominium, Seattle, Washington — 2025 benchmarking disclosure”, https://buildingcensus.com/buildings/seattle/lake-union-house-the-condominium-6852dbd7 (data as of October 2, 2026).