At a glance
46 Blackstone St is a 44,041-square-foot office building in Cambridge, Massachusetts, built in 2005. In its 2024 Cambridge benchmarking disclosure it reported an ENERGY STAR score of 58 out of 100 (grade C), a site energy-use intensity of 82.5 kBtu/ft² and 249 tCO₂e of greenhouse-gas emissions. That score is higher than 30% of the 94 scored office buildings in Cambridge.
BEUDO · reporting year 2024
Benchmarking record
| Field | Value |
|---|---|
| ENERGY STAR score | 58 (band C) |
| Site EUI | 82.5 kBtu/ft² |
| Source EUI | 149.0 kBtu/ft² |
| GHG emissions | 249 tCO₂e |
| GHG intensity | — |
| Electricity | 402,679 kWh |
| Water use | 93 kgal |
| Gross floor area | 44,041 sq ft |
| Source record | cambridge:B1325:2024 |
The disclosure history
Year over year
| Year | Score | Δ | Site EUI | GHG emissions |
|---|---|---|---|---|
| 2024latest | 58 | -6 | 82.5 kBtu/ft² | 249 tCO₂e |
| 2023 | 64 | -1 | 74.3 kBtu/ft² | 225 tCO₂e |
| 2022 | 65 | -7 | 78.5 kBtu/ft² | 236 tCO₂e |
| 2021 | 72 | +5 | 69.8 kBtu/ft² | 210 tCO₂e |
| 2020 | 67 | +16 | 75.9 kBtu/ft² | 227 tCO₂e |
| 2019 | 51 | -15 | 97.6 kBtu/ft² | 284 tCO₂e |
| 2018 | 66 | -4 | 71.2 kBtu/ft² | 213 tCO₂e |
| 2017 | 70 | +3 | 66.4 kBtu/ft² | 205 tCO₂e |
| 2016 | 67 | -5 | 69.0 kBtu/ft² | 213 tCO₂e |
| 2015 | 72 | 67.1 kBtu/ft² | 208 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
- 46 Blackstone St
- City
- Cambridge
- State
- Massachusetts
- Coordinates
- 42.36360, -71.11490
Within ~1 km
Nearby benchmarked buildings
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- 95 Dunster Stscore —
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- 111 Plympton Stscore —
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- 111 Plympton Stscore —
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- 111 Plympton Stscore —
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See also: most efficient in Cambridge · biggest emitters
How does 46 Blackstone St compare with other office buildings in Cambridge?
The latest disclosures cover 117 office buildings in Cambridge, out of 902 buildings citywide. 46 Blackstone St's ENERGY STAR score of 58 compares with an average of 64 across the 94 that report a score; it scores higher than 30% of them and lower than 68%. Its site EUI of 82.5 kBtu/ft² is roughly in line with the average of 78.7 kBtu/ft².
At 44,041 sq ft, it is about 64% below the average floor area of 121,167 sq ft for those buildings. It was built in 2005, 40 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 46 Blackstone St's energy performance changed over time?
BuildingCensus holds 10 Cambridge disclosures for 46 Blackstone St, covering report years 2015–2024. Its ENERGY STAR score went from 72 in 2015 to 58 in 2024 (-14 points); its best year on file was 2015, at 72. Site EUI moved from 67.1 kBtu/ft² (2015) to 82.5 kBtu/ft² (2024), an 23% increase. Reported emissions went from 208 tCO₂e to 249 tCO₂e over the same span (up 20%).
What does an ENERGY STAR score of 58 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 58 means the building performs better than about 58% of its national peers. BuildingCensus bands the score into report-card grades; 58 falls in band C — below median (55–69). It sits 17 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. 46 Blackstone St's 82.5 kBtu/ft² across 44,041 sq ft works out to about 3.6 billion Btu (1,065 MWh-equivalent) in 2024. Its source EUI of 149.0 kBtu/ft² also counts the energy lost generating and delivering that power, which is why it is higher. The disclosure also reports 402,679 kWh of electricity and 93 thousand gallons of water for the year.
Which law requires 46 Blackstone St to report its energy use?
46 Blackstone St 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:B1325:2024). 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
- 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)
- 139 Main St· 41,857 sq ft · score 80 (B)
- 485 Mass Ave.· 39,961 sq ft · score 15 (D)
- 130 Prospect Street· 37,916 sq ft · score 90 (A)
- 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 46 Blackstone St's energy grade?
46 Blackstone St scores 58 out of 100 on ENERGY STAR — band C, below median (55–69) — in its 2024 Cambridge disclosure. Scores are national percentiles against similar buildings; 75+ qualifies for ENERGY STAR certification.
How much energy does 46 Blackstone St use?
Its 2024 site energy-use intensity was 82.5 kBtu/ft² (149.0 kBtu/ft² source) across 44,041 sq ft, including 402,679 kWh of electricity.
What are 46 Blackstone St's carbon emissions?
46 Blackstone St reported 249 tCO₂e of greenhouse-gas emissions for 2024.
Where is 46 Blackstone St?
46 Blackstone St is in Cambridge, Massachusetts. Its coordinates are 42.36360, -71.11490 (latitude, longitude), as published in the Building Energy Use Disclosure Ordinance (BEUDO) file.
How big is 46 Blackstone St and when was it built?
46 Blackstone St has 44,041 sq ft of gross floor area, as reported in its 2024 disclosure. The disclosure lists 2005 as its year built. It is classed as office.
Is 46 Blackstone St 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, “46 Blackstone St, Cambridge, Massachusetts — 2024 benchmarking disclosure”, https://buildingcensus.com/buildings/cambridge/46-blackstone-st-befb0f2b (data as of October 2, 2026).