27 Union Sq
Office in New York City, NY · 27 Union Square · 10003
At a glance
27 Union Sq is a 52,850-square-foot office building at 27 Union Square in New York City, New York, built in 1950. In its 2024 New York City benchmarking disclosure it reported an ENERGY STAR score of 65 out of 100 (grade C), a site energy-use intensity of 85.9 kBtu/ft² and 459 tCO₂e of greenhouse-gas emissions. That score is higher than 29% 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 | 65 (band C) |
| Site EUI | 85.9 kBtu/ft² |
| Source EUI | 196.2 kBtu/ft² |
| GHG emissions | 459 tCO₂e |
| GHG intensity | 8.7 kgCO₂e/ft² |
| Electricity | 943,981 kWh |
| Natural gas | 4,497 therms |
| Water use | 2,318 kgal |
| Gross floor area | 52,850 sq ft |
| Source record | nyc:9051738:2024 |
The disclosure history
Year over year
| Year | Score | Δ | Site EUI | GHG emissions |
|---|---|---|---|---|
| 2024latest | 65 | -3 | 85.9 kBtu/ft² | 459 tCO₂e |
| 2023 | 68 | -11 | 84.7 kBtu/ft² | 429 tCO₂e |
| 2022 | 79 | 73.6 kBtu/ft² | 311 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
- 27 Union Square
- City
- New York City
- State
- New York
- ZIP
- 10003
- Coordinates
- 40.73636, -73.99089
Within ~1 km
Nearby benchmarked buildings
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See also: most efficient in New York City · biggest emitters
How does 27 Union Sq 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. 27 Union Sq's ENERGY STAR score of 65 compares with an average of 72 across the 2,519 that report a score; it scores higher than 29% of them and lower than 70%. Its site EUI of 85.9 kBtu/ft² is about 33% above the average of 64.5 kBtu/ft² — it uses more energy per square foot than the typical building in that group. Its emissions intensity of 8.7 kgCO₂e/ft² is about 50% above the group average of 5.8 kgCO₂e/ft².
At 52,850 sq ft, it is about 74% below the average floor area of 205,440 sq ft for those buildings. It was built in 1950, 10 years later 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 27 Union Sq's energy performance changed over time?
BuildingCensus holds 3 New York City disclosures for 27 Union Sq, covering report years 2022–2024. Its ENERGY STAR score went from 79 in 2022 to 65 in 2024 (-14 points); its best year on file was 2022, at 79. Site EUI moved from 73.6 kBtu/ft² (2022) to 85.9 kBtu/ft² (2024), an 17% increase. Reported emissions went from 311 tCO₂e to 459 tCO₂e over the same span (up 48%).
What does an ENERGY STAR score of 65 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 65 means the building performs better than about 65% of its national peers. BuildingCensus bands the score into report-card grades; 65 falls in band C — below median (55–69). It sits 10 points below 75, the threshold for ENERGY STAR certification. 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. 27 Union Sq's 85.9 kBtu/ft² across 52,850 sq ft works out to about 4.5 billion Btu (1,330 MWh-equivalent) in 2024. Its source EUI of 196.2 kBtu/ft² also counts the energy lost generating and delivering that power, which is why it is higher. The disclosure also reports 943,981 kWh of electricity, 4,497 therms of natural gas and 2,318 thousand gallons of water for the year.
Which law requires 27 Union Sq to report its energy use?
27 Union Sq 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:9051738:2024). 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.
More office buildings in New York City
- 36-36 Main Street· 52,796 sq ft · score 51 (D)
- ACHS Management: 89-30 Sutphin· 52,761 sq ft · EUI 95.0 kBtu/ft²
- New York Midtown Corp : 222 W 37 ST· 52,751 sq ft · EUI 45.5 kBtu/ft²
- 147 Prince Street· 52,700 sq ft · score 77 (B)
- 132 WEST 14 STREET:· 52,700 sq ft · score 83 (B)
- 545 Broadway· 52,648 sq ft · score 92 (A)
- 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 27 Union Sq's energy grade?
27 Union Sq scores 65 out of 100 on ENERGY STAR — band C, below median (55–69) — in its 2024 New York City disclosure. Scores are national percentiles against similar buildings; 75+ qualifies for ENERGY STAR certification.
How much energy does 27 Union Sq use?
Its 2024 site energy-use intensity was 85.9 kBtu/ft² (196.2 kBtu/ft² source) across 52,850 sq ft, including 943,981 kWh of electricity and 4,497 therms of natural gas.
What are 27 Union Sq's carbon emissions?
27 Union Sq reported 459 tCO₂e of greenhouse-gas emissions (8.7 kgCO₂e/ft²) for 2024.
Where is 27 Union Sq?
27 Union Sq is at 27 Union Square, in New York City, New York 10003. Its coordinates are 40.73636, -73.99089 (latitude, longitude), as published in the Energy and Water Data Disclosure file.
How big is 27 Union Sq and when was it built?
27 Union Sq has 52,850 sq ft of gross floor area, as reported in its 2024 disclosure. The disclosure lists 1950 as its year built. It is classed as office.
Is 27 Union Sq 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, “27 Union Sq, New York City, New York — 2024 benchmarking disclosure”, https://buildingcensus.com/buildings/new-york-city/27-union-sq-f2403e24 (data as of October 2, 2026).