At a glance
51 Brattle Street is a 46,245-square-foot office building in Cambridge, Massachusetts, built in 2006. In its 2024 Cambridge benchmarking disclosure it reported an ENERGY STAR score of 45 out of 100 (grade D), a site energy-use intensity of 88.7 kBtu/ft² and 258 tCO₂e of greenhouse-gas emissions. That score is higher than 20% of the 94 scored office buildings in Cambridge.
BEUDO · reporting year 2024
Benchmarking record
| Field | Value |
|---|---|
| ENERGY STAR score | 45 (band D) |
| Site EUI | 88.7 kBtu/ft² |
| Source EUI | 172.4 kBtu/ft² |
| GHG emissions | 258 tCO₂e |
| GHG intensity | — |
| Electricity | 613,653 kWh |
| Natural gas | 20,099 therms |
| Water use | 461 kgal |
| Gross floor area | 46,245 sq ft |
| Source record | cambridge:B1287:2024 |
The disclosure history
Year over year
| Year | Score | Δ | Site EUI | GHG emissions |
|---|---|---|---|---|
| 2024latest | 45 | ±0 | 88.7 kBtu/ft² | 258 tCO₂e |
| 2023 | 45 | -16 | 91.7 kBtu/ft² | 262 tCO₂e |
| 2022 | 61 | -2 | 67.0 kBtu/ft² | 199 tCO₂e |
| 2021 | 63 | +4 | 77.1 kBtu/ft² | 217 tCO₂e |
| 2020 | 59 | +22 | 72.3 kBtu/ft² | 209 tCO₂e |
| 2019 | 37 | +10 | 95.9 kBtu/ft² | 266 tCO₂e |
| 2018 | 27 | +1 | 102.9 kBtu/ft² | 305 tCO₂e |
| 2017 | 26 | -8 | 108.4 kBtu/ft² | 330 tCO₂e |
| 2016 | 34 | +8 | 91.8 kBtu/ft² | 285 tCO₂e |
| 2015 | 26 | 108.9 kBtu/ft² | 337 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
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Location
- Address
- 51 Brattle Street
- City
- Cambridge
- State
- Massachusetts
- Coordinates
- 42.37450, -71.12150
Within ~1 km
Nearby benchmarked buildings
- 52 Oxford Stscore —
College/University · 551,387 sq ft
- 1 Bennet Streetscore 67
Hotel · 498,000 sq ft
- 900 Memorial Drivescore 47
Multifamily Housing · 450,849 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
See also: most efficient in Cambridge · biggest emitters
How does 51 Brattle Street compare with other office buildings in Cambridge?
The latest disclosures cover 117 office buildings in Cambridge, out of 902 buildings citywide. 51 Brattle Street's ENERGY STAR score of 45 compares with an average of 64 across the 94 that report a score; it scores higher than 20% of them and lower than 78%. Its site EUI of 88.7 kBtu/ft² is about 13% above the average of 78.7 kBtu/ft² — it uses more energy per square foot than the typical building in that group.
At 46,245 sq ft, it is about 62% below the average floor area of 121,167 sq ft for those buildings. It was built in 2006, 41 years later than the group's average year built (1965). 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 51 Brattle Street's energy performance changed over time?
BuildingCensus holds 10 Cambridge disclosures for 51 Brattle Street, covering report years 2015–2024. Its ENERGY STAR score went from 26 in 2015 to 45 in 2024 (+19 points); its best year on file was 2021, at 63. Site EUI moved from 108.9 kBtu/ft² (2015) to 88.7 kBtu/ft² (2024), a 19% decrease. Reported emissions went from 337 tCO₂e to 258 tCO₂e over the same span (down 23%).
What does an ENERGY STAR score of 45 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 45 means the building performs better than about 45% of its national peers. BuildingCensus bands the score into report-card grades; 45 falls in band D — lowest band (1–54). It sits 30 points below 75, the threshold for ENERGY STAR certification. In Cambridge, 50% 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. 51 Brattle Street's 88.7 kBtu/ft² across 46,245 sq ft works out to about 4.1 billion Btu (1,202 MWh-equivalent) in 2024. Its source EUI of 172.4 kBtu/ft² also counts the energy lost generating and delivering that power, which is why it is higher. The disclosure also reports 613,653 kWh of electricity, 20,099 therms of natural gas and 461 thousand gallons of water for the year.
Which law requires 51 Brattle Street to report its energy use?
51 Brattle 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:B1287:2024). 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 office buildings in Cambridge
- 125 Mount Auburn Street· 46,085 sq ft · score 32 (D)
- 733 Concord Avenue· 44,048 sq ft · EUI 196.0 kBtu/ft²
- 46 Blackstone St· 44,041 sq ft · score 58 (C)
- 130 Bishop Allen Drive· 42,390 sq ft · score 62 (C)
- 1280 Massachusetts Avenue· 42,368 sq ft · score 22 (D)
- 264 Main St· 42,126 sq ft · score 50 (D)
- Office buildings in Cambridge· 117 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 51 Brattle Street's energy grade?
51 Brattle Street scores 45 out of 100 on ENERGY STAR — band D, lowest band (1–54) — in its 2024 Cambridge disclosure. Scores are national percentiles against similar buildings; 75+ qualifies for ENERGY STAR certification.
How much energy does 51 Brattle Street use?
Its 2024 site energy-use intensity was 88.7 kBtu/ft² (172.4 kBtu/ft² source) across 46,245 sq ft, including 613,653 kWh of electricity and 20,099 therms of natural gas.
What are 51 Brattle Street's carbon emissions?
51 Brattle Street reported 258 tCO₂e of greenhouse-gas emissions for 2024.
Where is 51 Brattle Street?
51 Brattle Street is in Cambridge, Massachusetts. Its coordinates are 42.37450, -71.12150 (latitude, longitude), as published in the Building Energy Use Disclosure Ordinance (BEUDO) file.
How big is 51 Brattle Street and when was it built?
51 Brattle Street has 46,245 sq ft of gross floor area, as reported in its 2024 disclosure. The disclosure lists 2006 as its year built. It is classed as office.
Is 51 Brattle 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, “51 Brattle Street, Cambridge, Massachusetts — 2024 benchmarking disclosure”, https://buildingcensus.com/buildings/cambridge/51-brattle-street-f5359ba0 (data as of October 2, 2026).