Duke Mansion
College/University in New York City, NY · 1 East 78 Street · 10075
At a glance
Duke Mansion is a 60,184-square-foot college/university building at 1 East 78 Street in New York City, New York, built in 1909. In its 2024 New York City benchmarking disclosure it reported a site energy-use intensity of 42.8 kBtu/ft² and 193 tCO₂e of greenhouse-gas emissions.
Local Law 84 (LL84) · reporting year 2024
Benchmarking record
| Field | Value |
|---|---|
| ENERGY STAR score | — |
| Site EUI | 42.8 kBtu/ft² |
| Source EUI | 71.2 kBtu/ft² |
| GHG emissions | 193 tCO₂e |
| GHG intensity | 3.2 kgCO₂e/ft² |
| Electricity | 264,818 kWh |
| Natural gas | 16,733 therms |
| Water use | 398 kgal |
| Gross floor area | 60,184 sq ft |
| Source record | nyc:5871172:2024 |
The disclosure history
Year over year
| Year | Score | Δ | Site EUI | GHG emissions |
|---|---|---|---|---|
| 2024latest | — | 42.8 kBtu/ft² | 193 tCO₂e | |
| 2023 | — | 41.6 kBtu/ft² | 180 tCO₂e | |
| 2022 | — | 49.9 kBtu/ft² | 191 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
- 1 East 78 Street
- City
- New York City
- State
- New York
- ZIP
- 10075
- Coordinates
- 40.77622, -73.96398
Within ~1 km
Nearby benchmarked buildings
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- Imperial Housescore 73
Multifamily Housing · 900,511 sq ft
- Imperial Housescore 69
Multifamily Housing · 884,999 sq ft
- Benchmarking Group - 209score —
College/University · 854,879 sq ft
- NH Lenox Hill Hospital Campusscore 64
Hospital (General Medical & Surgical) · 850,896 sq ft
See also: most efficient in New York City · biggest emitters
How does Duke Mansion compare with other college/university buildings in New York City?
The latest disclosures cover 553 college/university buildings in New York City, out of 48,310 buildings citywide. Its site EUI of 42.8 kBtu/ft² is about half of the average of 94.5 kBtu/ft² — it uses less energy per square foot than the typical building in that group. Its emissions intensity of 3.2 kgCO₂e/ft² is about half of the group average of 6.0 kgCO₂e/ft².
At 60,184 sq ft, it is about 70% below the average floor area of 202,329 sq ft for those buildings. It was built in 1909, 38 years earlier than the group's average year built (1947). Across all 24 jurisdictions BuildingCensus covers, the 2,113 college/university buildings average an ENERGY STAR score of 68 and a site EUI of 98.7 kBtu/ft².
How has Duke Mansion's energy performance changed over time?
BuildingCensus holds 3 New York City disclosures for Duke Mansion, covering report years 2022–2024. Site EUI moved from 49.9 kBtu/ft² (2022) to 42.8 kBtu/ft² (2024), a 14% decrease. Reported emissions went from 191 tCO₂e to 193 tCO₂e over the same span (up 1%).
What does a site EUI of 42.8 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. Duke Mansion's 42.8 kBtu/ft² across 60,184 sq ft works out to about 2.6 billion Btu (755 MWh-equivalent) in 2024. Its source EUI of 71.2 kBtu/ft² also counts the energy lost generating and delivering that power, which is why it is higher. The disclosure also reports 264,818 kWh of electricity, 16,733 therms of natural gas and 398 thousand gallons of water for the year.
Which law requires Duke Mansion to report its energy use?
Duke Mansion 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:5871172:2024). 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 college/university buildings in New York City
- Waverly Building· 60,107 sq ft · EUI 113.5 kBtu/ft²
- Mathematics· 60,033 sq ft
- Lewisohn· 59,997 sq ft
- St. Joseph's College· 59,800 sq ft · EUI 25.7 kBtu/ft²
- 515 West 185th Street· 59,675 sq ft · EUI 111.1 kBtu/ft²
- 66 5th Ave· 59,487 sq ft · EUI 34.4 kBtu/ft²
- College/University buildings in New York City· 553 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 Duke Mansion's energy grade?
Duke Mansion did not report an ENERGY STAR score in its 2024 disclosure, but its site energy-use intensity was 42.8 kBtu/ft².
How much energy does Duke Mansion use?
Its 2024 site energy-use intensity was 42.8 kBtu/ft² (71.2 kBtu/ft² source) across 60,184 sq ft, including 264,818 kWh of electricity and 16,733 therms of natural gas.
What are Duke Mansion's carbon emissions?
Duke Mansion reported 193 tCO₂e of greenhouse-gas emissions (3.2 kgCO₂e/ft²) for 2024.
Where is Duke Mansion?
Duke Mansion is at 1 East 78 Street, in New York City, New York 10075. Its coordinates are 40.77622, -73.96398 (latitude, longitude), as published in the Energy and Water Data Disclosure file.
How big is Duke Mansion and when was it built?
Duke Mansion has 60,184 sq ft of gross floor area, as reported in its 2024 disclosure. The disclosure lists 1909 as its year built. It is classed as college/university.
Is Duke Mansion 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, “Duke Mansion, New York City, New York — 2024 benchmarking disclosure”, https://buildingcensus.com/buildings/new-york-city/duke-mansion-44991e15 (data as of October 2, 2026).