Cosmos Club
Hotel in Washington, DC, DC · 2121 Massachusetts Ave., NW · 20008
At a glance
Cosmos Club is a 75,520-square-foot hotel at 2121 Massachusetts Ave., NW in Washington, DC, built in 1910. In its 2024 Washington, DC benchmarking disclosure it reported an ENERGY STAR score of 58 out of 100 (grade C), a site energy-use intensity of 141.5 kBtu/ft² and 741 tCO₂e of greenhouse-gas emissions. That score is higher than 46% of the 251 scored hotel buildings in Washington, DC.
Clean and Affordable Energy Act / BEPS · reporting year 2024
Benchmarking record
| Field | Value |
|---|---|
| ENERGY STAR score | 58 (band C) |
| Site EUI | 141.5 kBtu/ft² |
| Source EUI | 264.8 kBtu/ft² |
| GHG emissions | 741 tCO₂e |
| GHG intensity | 9.8 kgCO₂e/ft² |
| Electricity | 1,470,596 kWh |
| Natural gas | 56,681 therms |
| Water use | 3,951 kgal |
| Gross floor area | 75,520 sq ft |
| Source record | dc:PM4559564:2024 |
The disclosure history
Year over year
| Year | Score | Δ | Site EUI | GHG emissions |
|---|---|---|---|---|
| 2024latest | 58 | -7 | 141.5 kBtu/ft² | 741 tCO₂e |
| 2023 | 65 | -3 | 132.9 kBtu/ft² | 692 tCO₂e |
| 2022 | 68 | +24 | 134.3 kBtu/ft² | 692 tCO₂e |
| 2021 | 44 | +7 | 115.5 kBtu/ft² | 683 tCO₂e |
| 2020 | 37 | -22 | 114.4 kBtu/ft² | 691 tCO₂e |
| 2019 | 59 | +3 | 135.0 kBtu/ft² | 778 tCO₂e |
| 2018 | 56 | 142.5 kBtu/ft² | 810 tCO₂e | |
| 2017 | — | 79.7 kBtu/ft² | 766 tCO₂e | |
| 2016 | — | 88.4 kBtu/ft² | 891 tCO₂e | |
| 2015 | — | 123.4 kBtu/ft² | 1,210 tCO₂e | |
| 2014 | — | 120.6 kBtu/ft² | 1,180 tCO₂e |
Compliance context
Clean and Affordable Energy Act / BEPS
DC's Building Energy Performance Standards (BEPS) require buildings below the performance standard to improve over compliance cycles (the first ends December 31, 2026; later cycles run five years), with penalties for buildings that fail to meet their pathway.
Ownership
COSMOS CLUB
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Location
- Address
- 2121 Massachusetts Ave., NW
- City
- Washington, DC
- State
- District of Columbia
- ZIP
- 20008
- Coordinates
- 38.91144, -77.04769
Within ~1 km
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See also: most efficient in Washington, DC · biggest emitters
How does Cosmos Club compare with other hotel buildings in Washington, DC?
The latest disclosures cover 257 hotel buildings in Washington, DC, out of 6,870 buildings citywide. Cosmos Club's ENERGY STAR score of 58 compares with an average of 58 across the 251 that report a score; it scores higher than 46% of them and lower than 52%. Its site EUI of 141.5 kBtu/ft² is about 62% above the average of 87.6 kBtu/ft² — it uses more energy per square foot than the typical building in that group. Its emissions intensity of 9.8 kgCO₂e/ft² is about 42% above the group average of 6.9 kgCO₂e/ft².
At 75,520 sq ft, it is about 67% below the average floor area of 227,860 sq ft for those buildings. It was built in 1910, 64 years earlier than the group's average year built (1974). Across all 24 jurisdictions BuildingCensus covers, the 3,812 hotel buildings average an ENERGY STAR score of 65 and a site EUI of 77.8 kBtu/ft².
How has Cosmos Club's energy performance changed over time?
BuildingCensus holds 11 Washington, DC disclosures for Cosmos Club, covering report years 2014–2024. Its ENERGY STAR score went from 56 in 2018 to 58 in 2024 (+2 points); its best year on file was 2022, at 68. Site EUI moved from 120.6 kBtu/ft² (2014) to 141.5 kBtu/ft² (2024), an 17% increase. Reported emissions went from 1,180 tCO₂e to 741 tCO₂e over the same span (down 37%).
What does an ENERGY STAR score of 58 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 58 means the building performs better than about 58% of its national peers. BuildingCensus bands the score into report-card grades; 58 falls in band C — below median (55–69). It sits 17 points below 75, the threshold for ENERGY STAR certification. In Washington, DC, 47% 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. Cosmos Club's 141.5 kBtu/ft² across 75,520 sq ft works out to about 10.7 billion Btu (3,132 MWh-equivalent) in 2024. Its source EUI of 264.8 kBtu/ft² also counts the energy lost generating and delivering that power, which is why it is higher. The disclosure also reports 1,470,596 kWh of electricity, 56,681 therms of natural gas and 3,951 thousand gallons of water for the year.
Which law requires Cosmos Club to report its energy use?
Cosmos Club reports under the Clean and Affordable Energy Act / BEPS, the legal basis of Washington, DC's Building Energy Benchmarking program, which publishes each covered building's annual benchmarking results. The record shown here is the report-year 2024 disclosure (source record dc:PM4559564:2024). DC's Building Energy Performance Standards (BEPS) require buildings below the performance standard to improve over compliance cycles (the first ends December 31, 2026; later cycles run five years), with penalties for buildings that fail to meet their pathway.
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Frequently asked questions
What is Cosmos Club's energy grade?
Cosmos Club scores 58 out of 100 on ENERGY STAR — band C, below median (55–69) — in its 2024 Washington, DC disclosure. Scores are national percentiles against similar buildings; 75+ qualifies for ENERGY STAR certification.
How much energy does Cosmos Club use?
Its 2024 site energy-use intensity was 141.5 kBtu/ft² (264.8 kBtu/ft² source) across 75,520 sq ft, including 1,470,596 kWh of electricity and 56,681 therms of natural gas.
What are Cosmos Club's carbon emissions?
Cosmos Club reported 741 tCO₂e of greenhouse-gas emissions (9.8 kgCO₂e/ft²) for 2024.
Where is Cosmos Club?
Cosmos Club is at 2121 Massachusetts Ave., NW, in Washington, DC 20008. Its coordinates are 38.91144, -77.04769 (latitude, longitude), as published in the Building Energy Benchmarking file.
How big is Cosmos Club and when was it built?
Cosmos Club has 75,520 sq ft of gross floor area, as reported in its 2024 disclosure. The disclosure lists 1910 as its year built. It is classed as hotel.
Is Cosmos Club covered by the Clean and Affordable Energy Act / BEPS?
Yes — it appears in the 2024 Building Energy Benchmarking disclosure, which lists the buildings reporting under the Clean and Affordable Energy Act / BEPS.
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About this data
Source: Building Energy Benchmarking (Clean and Affordable Energy Act / BEPS), as published July 9, 2026. See the methodology for how records are matched, cleaned and scored.
Cite as: BuildingCensus, “Cosmos Club, Washington, DC — 2024 benchmarking disclosure”, https://buildingcensus.com/buildings/washington-dc/cosmos-club-300fb6c1 (data as of July 9, 2026).