600 - 435 West 23rd Street
Multifamily Housing in New York City, NY · 435 West 23rd Street · 10011
At a glance
600 - 435 West 23rd Street is a 975,170-square-foot multifamily housing building in New York City, New York, built in 1934. In its 2024 New York City benchmarking disclosure it reported an ENERGY STAR score of 88 out of 100 (grade A), a site energy-use intensity of 62.4 kBtu/ft² and 3,997 tCO₂e of greenhouse-gas emissions. That score is higher than 74% of the 22,829 scored multifamily housing buildings in New York City.
Local Law 84 (LL84) · reporting year 2024
Benchmarking record
| Field | Value |
|---|---|
| ENERGY STAR score | 88 (band A) |
| Site EUI | 62.4 kBtu/ft² |
| Source EUI | 87.7 kBtu/ft² |
| GHG emissions | 3,997 tCO₂e |
| GHG intensity | 4.1 kgCO₂e/ft² |
| Electricity | 3,610,623 kWh |
| Natural gas | 485,545 therms |
| Gross floor area | 975,170 sq ft |
| Source record | nyc:33987261:2024 |
The disclosure history
Year over year
| Year | Score | Δ | Site EUI | GHG emissions |
|---|---|---|---|---|
| 2024latest | 88 | +5 | 62.4 kBtu/ft² | 3,997 tCO₂e |
| 2023 | 83 | 69.5 kBtu/ft² | 4,158 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
- 435 West 23rd Street
- City
- New York City
- State
- New York
- ZIP
- 10011
- Coordinates
- 40.74697, -74.00244
Within ~1 km
Nearby benchmarked buildings
- Hudson Yards Cogen Campusscore —
Other · 7,739,076 sq ft
- Manhattan Westscore —
Other · 4,153,954 sq ft
- 20-30 Hudson Yardsscore —
Office · 3,810,623 sq ft
- Penn Southscore 95
Multifamily Housing · 3,391,963 sq ft
- 50 Hudson Yardsscore 76
Office · 2,944,455 sq ft
- The Spiral - 66 Hudson Boulevardscore 82
Office · 2,830,000 sq ft
See also: most efficient in New York City · biggest emitters
How does 600 - 435 West 23rd Street 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. 600 - 435 West 23rd Street's ENERGY STAR score of 88 compares with an average of 63 across the 22,829 that report a score; it scores higher than 74% of them and lower than 25%. Its site EUI of 62.4 kBtu/ft² is about 17% below the average of 74.9 kBtu/ft² — it uses less energy per square foot than the typical building in that group. Its emissions intensity of 4.1 kgCO₂e/ft² is about 21% below the group average of 5.2 kgCO₂e/ft².
At 975,170 sq ft, it is about 866% above the average floor area of 100,951 sq ft for those buildings. It was built in 1934, 18 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 600 - 435 West 23rd Street's energy performance changed over time?
BuildingCensus holds 2 New York City disclosures for 600 - 435 West 23rd Street, covering report years 2023–2024. Its ENERGY STAR score went from 83 in 2023 to 88 in 2024 (+5 points). Site EUI moved from 69.5 kBtu/ft² (2023) to 62.4 kBtu/ft² (2024), a 10% decrease. Reported emissions went from 4,158 tCO₂e to 3,997 tCO₂e over the same span (down 4%).
What does an ENERGY STAR score of 88 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 88 means the building performs better than about 88% of its national peers. BuildingCensus bands the score into report-card grades; 88 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. 600 - 435 West 23rd Street's 62.4 kBtu/ft² across 975,170 sq ft works out to about 60.9 billion Btu (17,834 MWh-equivalent) in 2024. Its source EUI of 87.7 kBtu/ft² also counts the energy lost generating and delivering that power, which is why it is higher. The disclosure also reports 3,610,623 kWh of electricity and 485,545 therms of natural gas for the year.
Which law requires 600 - 435 West 23rd Street to report its energy use?
600 - 435 West 23rd Street 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:33987261:2024). 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
- KINGSBOROUGH/KINGSBOROUGH EXTENSION· 975,000 sq ft · EUI 1.4 kBtu/ft²
- KINGSBOROUGH/KINGSBOROUGH EXTENSION CAMPUS· 975,000 sq ft · score 11 (D)
- 101 Lincoln Ave· 973,381 sq ft · score 95 (A)
- AKAM - Campus - Park City Estates· 970,397 sq ft · score 61 (C)
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- 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 600 - 435 West 23rd Street's energy grade?
600 - 435 West 23rd Street scores 88 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 600 - 435 West 23rd Street use?
Its 2024 site energy-use intensity was 62.4 kBtu/ft² (87.7 kBtu/ft² source) across 975,170 sq ft, including 3,610,623 kWh of electricity and 485,545 therms of natural gas.
What are 600 - 435 West 23rd Street's carbon emissions?
600 - 435 West 23rd Street reported 3,997 tCO₂e of greenhouse-gas emissions (4.1 kgCO₂e/ft²) for 2024.
Where is 600 - 435 West 23rd Street?
600 - 435 West 23rd Street is in New York City, New York 10011. Its coordinates are 40.74697, -74.00244 (latitude, longitude), as published in the Energy and Water Data Disclosure file.
How big is 600 - 435 West 23rd Street and when was it built?
600 - 435 West 23rd Street has 975,170 sq ft of gross floor area, as reported in its 2024 disclosure. The disclosure lists 1934 as its year built. It is classed as multifamily housing.
Is 600 - 435 West 23rd Street 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, “600 - 435 West 23rd Street, New York City, New York — 2024 benchmarking disclosure”, https://buildingcensus.com/buildings/new-york-city/600-435-west-23rd-street-6478c8a7 (data as of October 2, 2026).