BuildingCensus
B

Beacon Tower Apts

Multifamily Housing in Seattle, WA · 1311 S MASSACHUSETTS ST · 98144

At a glance

Beacon Tower Apts is a 73,898-square-foot multifamily housing building at 1311 S MASSACHUSETTS ST in Seattle, Washington, built in 1971. In its 2025 Seattle benchmarking disclosure it reported an ENERGY STAR score of 77 out of 100 (grade B), a site energy-use intensity of 41.6 kBtu/ft² and 67 tCO₂e of greenhouse-gas emissions. That score is higher than 25% of the 1,652 scored multifamily housing buildings in Seattle.

ENERGY STAR score
77
band B · 2025
Site EUI
41.6
kBtu/ft²
GHG emissions
67
tCO₂e
GHG intensity
0.8
kgCO₂e/ft²
Floor area
73,898
sq ft
Year built
1971
vintage
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85–10070–8455–691–54
This entry + 6 nearby

Seattle Energy Benchmarking Ordinance (SMC 22.920) · reporting year 2025

Benchmarking record

FieldValue
ENERGY STAR score77 (band B)
Site EUI41.6 kBtu/ft²
Source EUI94.4 kBtu/ft²
GHG emissions67 tCO₂e
GHG intensity0.8 kgCO₂e/ft²
Electricity679,334 kWh
Natural gas10,069 therms
Gross floor area73,898 sq ft
Source recordseattle:25046:2025

The disclosure history

Year over year

YearScoreΔSite EUIGHG emissions
2025latest77+341.6 kBtu/ft²67 tCO₂e
202474-142.1 kBtu/ft²66 tCO₂e
202375+642.9 kBtu/ft²68 tCO₂e
202269-146.5 kBtu/ft²76 tCO₂e
202170+845.9 kBtu/ft²77 tCO₂e
202062-747.4 kBtu/ft²81 tCO₂e
201969-945.3 kBtu/ft²78 tCO₂e
201878-442.1 kBtu/ft²74 tCO₂e
201782+741.5 kBtu/ft²70 tCO₂e
201675+4340.3 kBtu/ft²69 tCO₂e
20153243.6 kBtu/ft²68 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.

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Ownership

No owning organisation shown. Names of private individuals in the disclosure are not published here.

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Location

Address
1311 S MASSACHUSETTS ST
State
Washington
ZIP
98144
Coordinates
47.58820, -122.31551

Within ~1 km

Nearby benchmarked buildings

See also: most efficient in Seattle · biggest emitters

How does Beacon Tower Apts 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. Beacon Tower Apts's ENERGY STAR score of 77 compares with an average of 83 across the 1,652 that report a score; it scores higher than 25% of them and lower than 74%. Its site EUI of 41.6 kBtu/ft² is about 19% 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 0.8 kgCO₂e/ft² is about 19% above the group average of 0.7 kgCO₂e/ft².

At 73,898 sq ft, it is about 15% below the average floor area of 86,468 sq ft for those buildings. It was built in 1971, 12 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 Beacon Tower Apts's energy performance changed over time?

BuildingCensus holds 11 Seattle disclosures for Beacon Tower Apts, covering report years 2015–2025. Its ENERGY STAR score went from 32 in 2015 to 77 in 2025 (+45 points); its best year on file was 2017, at 82. Site EUI moved from 43.6 kBtu/ft² (2015) to 41.6 kBtu/ft² (2025), a 5% decrease. Reported emissions went from 68 tCO₂e to 67 tCO₂e over the same span (down 2%).

What does an ENERGY STAR score of 77 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 77 means the building performs better than about 77% of its national peers. BuildingCensus bands the score into report-card grades; 77 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. Beacon Tower Apts's 41.6 kBtu/ft² across 73,898 sq ft works out to about 3.1 billion Btu (901 MWh-equivalent) in 2025. Its source EUI of 94.4 kBtu/ft² also counts the energy lost generating and delivering that power, which is why it is higher. The disclosure also reports 679,334 kWh of electricity and 10,069 therms of natural gas for the year.

Which law requires Beacon Tower Apts to report its energy use?

Beacon Tower Apts 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:25046:2025). 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

Frequently asked questions

What is Beacon Tower Apts's energy grade?

Beacon Tower Apts scores 77 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 Beacon Tower Apts use?

Its 2025 site energy-use intensity was 41.6 kBtu/ft² (94.4 kBtu/ft² source) across 73,898 sq ft, including 679,334 kWh of electricity and 10,069 therms of natural gas.

What are Beacon Tower Apts's carbon emissions?

Beacon Tower Apts reported 67 tCO₂e of greenhouse-gas emissions (0.8 kgCO₂e/ft²) for 2025.

Where is Beacon Tower Apts?

Beacon Tower Apts is at 1311 S MASSACHUSETTS ST, in Seattle, Washington 98144. Its coordinates are 47.58820, -122.31551 (latitude, longitude), as published in the Building Energy Benchmarking file.

How big is Beacon Tower Apts and when was it built?

Beacon Tower Apts has 73,898 sq ft of gross floor area, as reported in its 2025 disclosure. The disclosure lists 1971 as its year built. It is classed as multifamily housing.

Is Beacon Tower Apts 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, “Beacon Tower Apts, Seattle, Washington — 2025 benchmarking disclosure”, https://buildingcensus.com/buildings/seattle/beacon-tower-apts-f1a24c1f (data as of October 2, 2026).