Marlborough House Condominium
Multifamily Housing in Seattle, WA · 1220 BOREN AVE · 98101
At a glance
Marlborough House Condominium is a 95,280-square-foot multifamily housing building at 1220 BOREN AVE in Seattle, Washington, built in 1927. In its 2025 Seattle benchmarking disclosure it reported an ENERGY STAR score of 100 out of 100 (grade A) and a site energy-use intensity of 12.5 kBtu/ft². That score is higher than 88% 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 | 100 (band A) |
| Site EUI | 12.5 kBtu/ft² |
| Source EUI | 34.9 kBtu/ft² |
| GHG emissions | — |
| GHG intensity | — |
| Electricity | 348,055 kWh |
| Gross floor area | 95,280 sq ft |
| Source record | seattle:25412:2025 |
The disclosure history
Year over year
| Year | Score | Δ | Site EUI | GHG emissions |
|---|---|---|---|---|
| 2025latest | 100 | ±0 | 12.5 kBtu/ft² | — |
| 2024 | 100 | +10 | 13.8 kBtu/ft² | 8 tCO₂e |
| 2023 | 90 | +2 | 23.9 kBtu/ft² | 8 tCO₂e |
| 2022 | 88 | +7 | 25.3 kBtu/ft² | 8 tCO₂e |
| 2021 | 81 | 27.1 kBtu/ft² | 9 tCO₂e | |
| 2020 | — | 56.6 kBtu/ft² | 261 tCO₂e | |
| 2019 | — | 68.3 kBtu/ft² | 347 tCO₂e | |
| 2018 | — | 63.4 kBtu/ft² | 317 tCO₂e | |
| 2017 | — | 66.0 kBtu/ft² | 333 tCO₂e | |
| 2016 | — | 60.4 kBtu/ft² | 293 tCO₂e | |
| 2015 | 49 | 57.1 kBtu/ft² | 274 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
- 1220 BOREN AVE
- City
- Seattle
- State
- Washington
- ZIP
- 98101
- Coordinates
- 47.61137, -122.32669
Within ~1 km
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See also: most efficient in Seattle · biggest emitters
How does Marlborough House 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. Marlborough House Condominium's ENERGY STAR score of 100 compares with an average of 83 across the 1,652 that report a score; it scores higher than 88% of them. Its site EUI of 12.5 kBtu/ft² is about 64% below the average of 34.9 kBtu/ft² — it uses less energy per square foot than the typical building in that group.
At 95,280 sq ft, it is about 10% above the average floor area of 86,468 sq ft for those buildings. It was built in 1927, 56 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 Marlborough House Condominium's energy performance changed over time?
BuildingCensus holds 11 Seattle disclosures for Marlborough House Condominium, covering report years 2015–2025. Its ENERGY STAR score went from 49 in 2015 to 100 in 2025 (+51 points); its best year on file was 2024, at 100. Site EUI moved from 57.1 kBtu/ft² (2015) to 12.5 kBtu/ft² (2025), a 78% decrease. Reported emissions went from 274 tCO₂e to 8 tCO₂e over the same span (down 97%).
What does an ENERGY STAR score of 100 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: 100 is the top of the scale. BuildingCensus bands the score into report-card grades; 100 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. Marlborough House Condominium's 12.5 kBtu/ft² across 95,280 sq ft works out to about 1.2 billion Btu (349 MWh-equivalent) in 2025. Its source EUI of 34.9 kBtu/ft² also counts the energy lost generating and delivering that power, which is why it is higher. The disclosure also reports 348,055 kWh of electricity for the year.
Which law requires Marlborough House Condominium to report its energy use?
Marlborough House 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:25412:2025). 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
- Aperture On Fifth· 94,909 sq ft · score 96 (A)
- Greenlake Plaza Apts· 94,410 sq ft · score 43 (D)
- Royal Manor Condominium· 94,000 sq ft · EUI 48.4 kBtu/ft²
- Savoy Lake City· 93,857 sq ft · score 97 (A)
- Malloy Apts· 93,502 sq ft · score 99 (A)
- Colonial Grand Pacific Condos· 93,433 sq ft · score 97 (A)
- 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 Marlborough House Condominium's energy grade?
Marlborough House Condominium scores 100 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 Marlborough House Condominium use?
Its 2025 site energy-use intensity was 12.5 kBtu/ft² (34.9 kBtu/ft² source) across 95,280 sq ft, including 348,055 kWh of electricity.
What are Marlborough House Condominium's carbon emissions?
No greenhouse-gas emissions figure was reported for 2025.
Where is Marlborough House Condominium?
Marlborough House Condominium is at 1220 BOREN AVE, in Seattle, Washington 98101. Its coordinates are 47.61137, -122.32669 (latitude, longitude), as published in the Building Energy Benchmarking file.
How big is Marlborough House Condominium and when was it built?
Marlborough House Condominium has 95,280 sq ft of gross floor area, as reported in its 2025 disclosure. The disclosure lists 1927 as its year built. It is classed as multifamily housing.
Is Marlborough House 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, “Marlborough House Condominium, Seattle, Washington — 2025 benchmarking disclosure”, https://buildingcensus.com/buildings/seattle/marlborough-house-condominium-7f8a6fea (data as of October 2, 2026).