Dew Seven: 45-51 West 21 St
Office in New York City, NY · 45-51 W 21 St · 10010
At a glance
Dew Seven: 45-51 West 21 St is a 74,900-square-foot office building at 45-51 W 21 St in New York City, New York, built in 1915. In its 2024 New York City benchmarking disclosure it reported an ENERGY STAR score of 85 out of 100 (grade A), a site energy-use intensity of 50.8 kBtu/ft² and 323 tCO₂e of greenhouse-gas emissions. That score is higher than 63% of the 2,519 scored office buildings in New York City.
Local Law 84 (LL84) · reporting year 2024
Benchmarking record
| Field | Value |
|---|---|
| ENERGY STAR score | 85 (band A) |
| Site EUI | 50.8 kBtu/ft² |
| Source EUI | 98.7 kBtu/ft² |
| GHG emissions | 323 tCO₂e |
| GHG intensity | 4.3 kgCO₂e/ft² |
| Electricity | 569,920 kWh |
| Natural gas | 18,585 therms |
| Water use | 896 kgal |
| Gross floor area | 74,900 sq ft |
| Source record | nyc:3917686:2024 |
The disclosure history
Year over year
| Year | Score | Δ | Site EUI | GHG emissions |
|---|---|---|---|---|
| 2024latest | 85 | -2 | 50.8 kBtu/ft² | 323 tCO₂e |
| 2023 | 87 | ±0 | 45.8 kBtu/ft² | 288 tCO₂e |
| 2022 | 87 | 48.7 kBtu/ft² | 250 tCO₂e |
Compliance context
Local Law 84 (LL84)
Under Local Law 97, buildings over 25,000 sq ft face carbon caps with fines of $268 per metric ton of CO₂e over the limit, phasing in from 2024.
Ownership
No owning organisation shown. Names of private individuals in the disclosure are not published here.
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Location
- Address
- 45-51 W 21 St
- City
- New York City
- State
- New York
- ZIP
- 10010
- Coordinates
- 40.74090, -73.99200
Within ~1 km
Nearby benchmarked buildings
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- One Madison Avenuescore —
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See also: most efficient in New York City · biggest emitters
How does Dew Seven: 45-51 West 21 St compare with other office buildings in New York City?
The latest disclosures cover 3,384 office buildings in New York City, out of 48,310 buildings citywide. Dew Seven: 45-51 West 21 St's ENERGY STAR score of 85 compares with an average of 72 across the 2,519 that report a score; it scores higher than 63% of them and lower than 35%. Its site EUI of 50.8 kBtu/ft² is about 21% below the average of 64.5 kBtu/ft² — it uses less energy per square foot than the typical building in that group. Its emissions intensity of 4.3 kgCO₂e/ft² is about 26% below the group average of 5.8 kgCO₂e/ft².
At 74,900 sq ft, it is about 64% below the average floor area of 205,440 sq ft for those buildings. It was built in 1915, 25 years earlier than the group's average year built (1940). Across all 24 jurisdictions BuildingCensus covers, the 15,264 office buildings average an ENERGY STAR score of 73 and a site EUI of 59.3 kBtu/ft².
How has Dew Seven: 45-51 West 21 St's energy performance changed over time?
BuildingCensus holds 3 New York City disclosures for Dew Seven: 45-51 West 21 St, covering report years 2022–2024. Its ENERGY STAR score went from 87 in 2022 to 85 in 2024 (-2 points); its best year on file was 2022, at 87. Site EUI moved from 48.7 kBtu/ft² (2022) to 50.8 kBtu/ft² (2024), an 4% increase. Reported emissions went from 250 tCO₂e to 323 tCO₂e over the same span (up 29%).
What does an ENERGY STAR score of 85 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 85 means the building performs better than about 85% of its national peers. BuildingCensus bands the score into report-card grades; 85 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 New York City, 43% 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. Dew Seven: 45-51 West 21 St's 50.8 kBtu/ft² across 74,900 sq ft works out to about 3.8 billion Btu (1,115 MWh-equivalent) in 2024. Its source EUI of 98.7 kBtu/ft² also counts the energy lost generating and delivering that power, which is why it is higher. The disclosure also reports 569,920 kWh of electricity, 18,585 therms of natural gas and 896 thousand gallons of water for the year.
Which law requires Dew Seven: 45-51 West 21 St to report its energy use?
Dew Seven: 45-51 West 21 St reports under Local Law 84 (LL84), the legal basis of New York City's Energy and Water Data Disclosure program, which publishes each covered building's annual benchmarking results. The record shown here is the report-year 2024 disclosure (source record nyc:3917686:2024). Under Local Law 97, buildings over 25,000 sq ft face carbon caps with fines of $268 per metric ton of CO₂e over the limit, phasing in from 2024.
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- Office buildings in New York City· 3,384 benchmarked
- All New York City benchmarked buildings· Local Law 84 (LL84)
- Most efficient large buildings in New York City
- Least efficient large buildings in New York City
- Biggest emitters in New York City
Frequently asked questions
What is Dew Seven: 45-51 West 21 St's energy grade?
Dew Seven: 45-51 West 21 St scores 85 out of 100 on ENERGY STAR — band A, high performer (85–100) — in its 2024 New York City disclosure. Scores are national percentiles against similar buildings; 75+ qualifies for ENERGY STAR certification.
How much energy does Dew Seven: 45-51 West 21 St use?
Its 2024 site energy-use intensity was 50.8 kBtu/ft² (98.7 kBtu/ft² source) across 74,900 sq ft, including 569,920 kWh of electricity and 18,585 therms of natural gas.
What are Dew Seven: 45-51 West 21 St's carbon emissions?
Dew Seven: 45-51 West 21 St reported 323 tCO₂e of greenhouse-gas emissions (4.3 kgCO₂e/ft²) for 2024.
Where is Dew Seven: 45-51 West 21 St?
Dew Seven: 45-51 West 21 St is at 45-51 W 21 St, in New York City, New York 10010. Its coordinates are 40.74090, -73.99200 (latitude, longitude), as published in the Energy and Water Data Disclosure file.
How big is Dew Seven: 45-51 West 21 St and when was it built?
Dew Seven: 45-51 West 21 St has 74,900 sq ft of gross floor area, as reported in its 2024 disclosure. The disclosure lists 1915 as its year built. It is classed as office.
Is Dew Seven: 45-51 West 21 St covered by Local Law 84 (LL84)?
Yes — it appears in the 2024 Energy and Water Data Disclosure disclosure, which lists the buildings reporting under Local Law 84 (LL84).
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About this data
Source: Energy and Water Data Disclosure (Local Law 84 (LL84)), as published October 2, 2026. See the methodology for how records are matched, cleaned and scored.
Cite as: BuildingCensus, “Dew Seven: 45-51 West 21 St, New York City, New York — 2024 benchmarking disclosure”, https://buildingcensus.com/buildings/new-york-city/dew-seven-45-51-west-21-st-70e92f4d (data as of October 2, 2026).