18 Mason Street
College/University in Cambridge, MA
At a glance
18 Mason Street is a 21,864-square-foot college/university building in Cambridge, Massachusetts, built in 1898. In its 2024 Cambridge benchmarking disclosure it reported a site energy-use intensity of 31.6 kBtu/ft² and 50 tCO₂e of greenhouse-gas emissions.
BEUDO · reporting year 2024
Benchmarking record
| Field | Value |
|---|---|
| ENERGY STAR score | — |
| Site EUI | 31.6 kBtu/ft² |
| Source EUI | 88.6 kBtu/ft² |
| GHG emissions | 50 tCO₂e |
| GHG intensity | — |
| Electricity | 202,701 kWh |
| Water use | 479 kgal |
| Gross floor area | 21,864 sq ft |
| Source record | cambridge:B1231:2024 |
The disclosure history
Year over year
| Year | Score | Δ | Site EUI | GHG emissions |
|---|---|---|---|---|
| 2024latest | — | 31.6 kBtu/ft² | 50 tCO₂e | |
| 2023 | — | 32.8 kBtu/ft² | 52 tCO₂e | |
| 2022 | — | 32.4 kBtu/ft² | 51 tCO₂e | |
| 2021 | — | 26.0 kBtu/ft² | 41 tCO₂e | |
| 2020 | — | 28.1 kBtu/ft² | 44 tCO₂e | |
| 2019 | — | 32.9 kBtu/ft² | 47 tCO₂e | |
| 2018 | — | 28.1 kBtu/ft² | 43 tCO₂e | |
| 2017 | — | 35.7 kBtu/ft² | 58 tCO₂e | |
| 2016 | — | 37.4 kBtu/ft² | 62 tCO₂e | |
| 2015 | — | 39.5 kBtu/ft² | 67 tCO₂e |
Compliance context
BEUDO
Cambridge's 2023 BEUDO amendments require non-residential buildings of 100,000+ sq ft to reach net-zero emissions by 2035 (reductions starting 2026) and those of 25,000–100,000 sq ft by 2050 (starting 2030).
Ownership
PRESIDENT & FELLOWS OF HARVARD COLLEGE
Own or manage this building? Claim it to correct the record and get compliance alerts.
Location
- Address
- 18 Mason Street
- City
- Cambridge
- State
- Massachusetts
- Coordinates
- 42.37620, -71.12280
Within ~1 km
Nearby benchmarked buildings
- 52 Oxford Stscore —
College/University · 551,387 sq ft
- 1 Bennet Streetscore 67
Hotel · 498,000 sq ft
- 1 Oxford Stscore —
College/University · 355,836 sq ft
- 75 Mount Auburn Streetscore 79
Office · 345,571 sq ft
- 1545 Massachusetts Avenuescore —
College/University · 281,097 sq ft
- 1586 Massachusetts Avenuescore —
College/University · 262,602 sq ft
See also: most efficient in Cambridge · biggest emitters
How does 18 Mason Street compare with other college/university buildings in Cambridge?
The latest disclosures cover 203 college/university buildings in Cambridge, out of 902 buildings citywide. Its site EUI of 31.6 kBtu/ft² is about 80% below the average of 154.3 kBtu/ft² — it uses less energy per square foot than the typical building in that group.
At 21,864 sq ft, it is about 77% below the average floor area of 96,964 sq ft for those buildings. It was built in 1898, 51 years earlier than the group's average year built (1949). 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 18 Mason Street's energy performance changed over time?
BuildingCensus holds 10 Cambridge disclosures for 18 Mason Street, covering report years 2015–2024. Site EUI moved from 39.5 kBtu/ft² (2015) to 31.6 kBtu/ft² (2024), a 20% decrease. Reported emissions went from 67 tCO₂e to 50 tCO₂e over the same span (down 26%).
What does a site EUI of 31.6 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. 18 Mason Street's 31.6 kBtu/ft² across 21,864 sq ft works out to about 0.7 billion Btu (202 MWh-equivalent) in 2024. Its source EUI of 88.6 kBtu/ft² also counts the energy lost generating and delivering that power, which is why it is higher. The disclosure also reports 202,701 kWh of electricity and 479 thousand gallons of water for the year.
Which law requires 18 Mason Street to report its energy use?
18 Mason Street reports under BEUDO, the legal basis of Cambridge's Building Energy Use Disclosure Ordinance (BEUDO), which publishes each covered building's annual benchmarking results. The record shown here is the report-year 2024 disclosure (source record cambridge:B1231:2024). Cambridge's 2023 BEUDO amendments require non-residential buildings of 100,000+ sq ft to reach net-zero emissions by 2035 (reductions starting 2026) and those of 25,000–100,000 sq ft by 2050 (starting 2030).
More college/university buildings in Cambridge
- 391 Harvard St· 20,923 sq ft · EUI 59.0 kBtu/ft²
- 19 Oxford Street· 20,360 sq ft · EUI 525.8 kBtu/ft²
- Main Yard· 20,316 sq ft · EUI 94.2 kBtu/ft²
- 111 MEMORIAL DR· 18,643 sq ft · EUI 95.0 kBtu/ft²
- 77 MASSACHUSETTS AVE· 18,502 sq ft
- 166-170 ALBANY ST· 16,137 sq ft · EUI 41.3 kBtu/ft²
- College/University buildings in Cambridge· 203 benchmarked
- All Cambridge benchmarked buildings· BEUDO
- Most efficient large buildings in Cambridge
- Least efficient large buildings in Cambridge
- Biggest emitters in Cambridge
Frequently asked questions
What is 18 Mason Street's energy grade?
18 Mason Street did not report an ENERGY STAR score in its 2024 disclosure, but its site energy-use intensity was 31.6 kBtu/ft².
How much energy does 18 Mason Street use?
Its 2024 site energy-use intensity was 31.6 kBtu/ft² (88.6 kBtu/ft² source) across 21,864 sq ft, including 202,701 kWh of electricity.
What are 18 Mason Street's carbon emissions?
18 Mason Street reported 50 tCO₂e of greenhouse-gas emissions for 2024.
Where is 18 Mason Street?
18 Mason Street is in Cambridge, Massachusetts. Its coordinates are 42.37620, -71.12280 (latitude, longitude), as published in the Building Energy Use Disclosure Ordinance (BEUDO) file.
How big is 18 Mason Street and when was it built?
18 Mason Street has 21,864 sq ft of gross floor area, as reported in its 2024 disclosure. The disclosure lists 1898 as its year built. It is classed as college/university.
Is 18 Mason Street covered by BEUDO?
Yes — it appears in the 2024 Building Energy Use Disclosure Ordinance (BEUDO) disclosure, which lists the buildings reporting under BEUDO.
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About this data
Source: Building Energy Use Disclosure Ordinance (BEUDO) (BEUDO), as published October 2, 2026. See the methodology for how records are matched, cleaned and scored.
Cite as: BuildingCensus, “18 Mason Street, Cambridge, Massachusetts — 2024 benchmarking disclosure”, https://buildingcensus.com/buildings/cambridge/18-mason-street-c0a61d49 (data as of October 2, 2026).