Altair 20
Multifamily Housing in New York City, NY · 15 W. 20Th Street · 10011
At a glance
Altair 20 is a 41,025-square-foot multifamily housing building at 15 W. 20Th Street in New York City, New York, built in 1906. In its 2024 New York City benchmarking disclosure it reported a site energy-use intensity of 79.6 kBtu/ft² and 272 tCO₂e of greenhouse-gas emissions.
Local Law 84 (LL84) · reporting year 2024
Benchmarking record
| Field | Value |
|---|---|
| ENERGY STAR score | — |
| Site EUI | 79.6 kBtu/ft² |
| Source EUI | 151.3 kBtu/ft² |
| GHG emissions | 272 tCO₂e |
| GHG intensity | 6.6 kgCO₂e/ft² |
| Electricity | 465,870 kWh |
| Natural gas | 16,745 therms |
| Water use | 1,047 kgal |
| Gross floor area | 41,025 sq ft |
| Source record | nyc:6303546:2024 |
The disclosure history
Year over year
| Year | Score | Δ | Site EUI | GHG emissions |
|---|---|---|---|---|
| 2024latest | — | 79.6 kBtu/ft² | 272 tCO₂e | |
| 2023 | — | 74.0 kBtu/ft² | 244 tCO₂e | |
| 2022 | — | 76.2 kBtu/ft² | 213 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
- 15 W. 20Th Street
- City
- New York City
- State
- New York
- ZIP
- 10011
- Coordinates
- 40.74002, -73.99174
Within ~1 km
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See also: most efficient in New York City · biggest emitters
How does Altair 20 compare with other multifamily housing buildings in New York City?
The latest disclosures cover 33,022 multifamily housing buildings in New York City, out of 48,310 buildings citywide. Its site EUI of 79.6 kBtu/ft² is roughly in line with the average of 74.9 kBtu/ft². Its emissions intensity of 6.6 kgCO₂e/ft² is about 27% above the group average of 5.2 kgCO₂e/ft².
At 41,025 sq ft, it is about 59% below the average floor area of 100,951 sq ft for those buildings. It was built in 1906, 46 years earlier than the group's average year built (1952). 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 Altair 20's energy performance changed over time?
BuildingCensus holds 3 New York City disclosures for Altair 20, covering report years 2022–2024. Site EUI moved from 76.2 kBtu/ft² (2022) to 79.6 kBtu/ft² (2024), an 4% increase. Reported emissions went from 213 tCO₂e to 272 tCO₂e over the same span (up 28%).
What does a site EUI of 79.6 kBtu/ft² mean?
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. Altair 20's 79.6 kBtu/ft² across 41,025 sq ft works out to about 3.3 billion Btu (957 MWh-equivalent) in 2024. Its source EUI of 151.3 kBtu/ft² also counts the energy lost generating and delivering that power, which is why it is higher. The disclosure also reports 465,870 kWh of electricity, 16,745 therms of natural gas and 1,047 thousand gallons of water for the year.
Which law requires Altair 20 to report its energy use?
Altair 20 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:6303546:2024). 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 multifamily housing buildings in New York City
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- Goldmont Realty - 625 West 156th Street· 41,016 sq ft · score 50 (D)
- EAST 56TH MANAGEMENT LLC· 41,016 sq ft · score 49 (D)
- 1025 Leggett Ave· 41,010 sq ft · score 60 (C)
- Green Light Energy Conservation : 2075 MORRIS AVENUE· 41,005 sq ft · score 70 (B)
- Chestnut - 2081 Morris Avenue· 41,005 sq ft · score 41 (D)
- Multifamily Housing buildings in New York City· 33,022 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 Altair 20's energy grade?
Altair 20 did not report an ENERGY STAR score in its 2024 disclosure, but its site energy-use intensity was 79.6 kBtu/ft².
How much energy does Altair 20 use?
Its 2024 site energy-use intensity was 79.6 kBtu/ft² (151.3 kBtu/ft² source) across 41,025 sq ft, including 465,870 kWh of electricity and 16,745 therms of natural gas.
What are Altair 20's carbon emissions?
Altair 20 reported 272 tCO₂e of greenhouse-gas emissions (6.6 kgCO₂e/ft²) for 2024.
Where is Altair 20?
Altair 20 is at 15 W. 20Th Street, in New York City, New York 10011. Its coordinates are 40.74002, -73.99174 (latitude, longitude), as published in the Energy and Water Data Disclosure file.
How big is Altair 20 and when was it built?
Altair 20 has 41,025 sq ft of gross floor area, as reported in its 2024 disclosure. The disclosure lists 1906 as its year built. It is classed as multifamily housing.
Is Altair 20 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, “Altair 20, New York City, New York — 2024 benchmarking disclosure”, https://buildingcensus.com/buildings/new-york-city/altair-20-31c807ce (data as of October 2, 2026).