Astro Apartments
Multifamily Housing in Seattle, WA · 315 1ST AVE N · 98109
At a glance
Astro Apartments is a 260,051-square-foot multifamily housing building at 315 1ST AVE N in Seattle, Washington, built in 2015. In its 2025 Seattle benchmarking disclosure it reported an ENERGY STAR score of 95 out of 100 (grade A), a site energy-use intensity of 43.5 kBtu/ft² and 150 tCO₂e of greenhouse-gas emissions. That score is higher than 61% 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 | 95 (band A) |
| Site EUI | 43.5 kBtu/ft² |
| Source EUI | 90.5 kBtu/ft² |
| GHG emissions | 150 tCO₂e |
| GHG intensity | 1.0 kgCO₂e/ft² |
| Electricity | 1,095,175 kWh |
| Natural gas | 26,060 therms |
| Gross floor area | 260,051 sq ft |
| Source record | seattle:50075:2025 |
The disclosure history
Year over year
| Year | Score | Δ | Site EUI | GHG emissions |
|---|---|---|---|---|
| 2025latest | 95 | -1 | 43.5 kBtu/ft² | 150 tCO₂e |
| 2024 | 96 | +1 | 41.9 kBtu/ft² | 151 tCO₂e |
| 2023 | 95 | +1 | 43.7 kBtu/ft² | 160 tCO₂e |
| 2022 | 94 | ±0 | 46.6 kBtu/ft² | 178 tCO₂e |
| 2021 | 94 | ±0 | 45.4 kBtu/ft² | 168 tCO₂e |
| 2020 | 94 | -3 | 45.1 kBtu/ft² | 169 tCO₂e |
| 2019 | 97 | -1 | 43.3 kBtu/ft² | 170 tCO₂e |
| 2018 | 98 | 38.9 kBtu/ft² | 141 tCO₂e | |
| 2017 | — | 39.2 kBtu/ft² | 143 tCO₂e | |
| 2016 | 98 | 36.5 kBtu/ft² | 120 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
- 315 1ST AVE N
- City
- Seattle
- State
- Washington
- ZIP
- 98109
- Coordinates
- 47.62157, -122.35569
Within ~1 km
Nearby benchmarked buildings
- Climate Pledge Arenascore —
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- Olympus Aptsscore 97
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Mixed Use Property · 524,610 sq ft
- Avalon Belltown Towersscore 72
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- Third And Broad Bldgscore 94
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- Armory - Seattle Centerscore —
Other · 396,085 sq ft
See also: most efficient in Seattle · biggest emitters
How does Astro Apartments 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. Astro Apartments's ENERGY STAR score of 95 compares with an average of 83 across the 1,652 that report a score; it scores higher than 61% of them and lower than 35%. Its site EUI of 43.5 kBtu/ft² is about 25% 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 1.0 kgCO₂e/ft² is about 47% above the group average of 0.7 kgCO₂e/ft².
At 260,051 sq ft, it is about 201% above the average floor area of 86,468 sq ft for those buildings. It was built in 2015, 32 years later 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 Astro Apartments's energy performance changed over time?
BuildingCensus holds 10 Seattle disclosures for Astro Apartments, covering report years 2016–2025. Its ENERGY STAR score went from 98 in 2016 to 95 in 2025 (-3 points); its best year on file was 2016, at 98. Site EUI moved from 36.5 kBtu/ft² (2016) to 43.5 kBtu/ft² (2025), an 19% increase. Reported emissions went from 120 tCO₂e to 150 tCO₂e over the same span (up 25%).
What does an ENERGY STAR score of 95 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 95 means the building performs better than about 95% of its national peers. BuildingCensus bands the score into report-card grades; 95 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. Astro Apartments's 43.5 kBtu/ft² across 260,051 sq ft works out to about 11.3 billion Btu (3,315 MWh-equivalent) in 2025. Its source EUI of 90.5 kBtu/ft² also counts the energy lost generating and delivering that power, which is why it is higher. The disclosure also reports 1,095,175 kWh of electricity and 26,060 therms of natural gas for the year.
Which law requires Astro Apartments to report its energy use?
Astro Apartments 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:50075:2025). 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
- Leilani On Greenwood Apts (North/South/West Combined)· 259,493 sq ft · score 100 (A)
- Augusta Apartments· 257,903 sq ft · score 100 (A)
- The Rise at Madison - Condominiums· 256,993 sq ft · score 93 (A)
- 624 Yale Apartments· 255,649 sq ft · score 92 (A)
- Radius Apts· 253,015 sq ft · score 99 (A)
- Iron Flats - North & West Buildings· 249,530 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 Astro Apartments's energy grade?
Astro Apartments scores 95 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 Astro Apartments use?
Its 2025 site energy-use intensity was 43.5 kBtu/ft² (90.5 kBtu/ft² source) across 260,051 sq ft, including 1,095,175 kWh of electricity and 26,060 therms of natural gas.
What are Astro Apartments's carbon emissions?
Astro Apartments reported 150 tCO₂e of greenhouse-gas emissions (1.0 kgCO₂e/ft²) for 2025.
Where is Astro Apartments?
Astro Apartments is at 315 1ST AVE N, in Seattle, Washington 98109. Its coordinates are 47.62157, -122.35569 (latitude, longitude), as published in the Building Energy Benchmarking file.
How big is Astro Apartments and when was it built?
Astro Apartments has 260,051 sq ft of gross floor area, as reported in its 2025 disclosure. The disclosure lists 2015 as its year built. It is classed as multifamily housing.
Is Astro Apartments 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, “Astro Apartments, Seattle, Washington — 2025 benchmarking disclosure”, https://buildingcensus.com/buildings/seattle/astro-apartments-c4253a42 (data as of October 2, 2026).