306-320 Potrero / 870 Hermosa
Office in California, CA · 306 Potrero Avenue, Sunnyvale · 94085
At a glance
306-320 Potrero / 870 Hermosa is a 50,104-square-foot office building at 306 Potrero Avenue, Sunnyvale in Sunnyvale, California, built in 1972. In its 2024 California benchmarking disclosure it reported an ENERGY STAR score of 99 out of 100 (grade A), a site energy-use intensity of 26.2 kBtu/ft² and 77 tCO₂e of greenhouse-gas emissions. That score is higher than 88% of the 4,912 scored office buildings in California.
AB 802 (Public Resources Code §25402.10) · reporting year 2024
Benchmarking record
| Field | Value |
|---|---|
| ENERGY STAR score | 99 (band A) |
| Site EUI | 26.2 kBtu/ft² |
| Source EUI | — |
| GHG emissions | 77 tCO₂e |
| GHG intensity | 1.5 kgCO₂e/ft² |
| Electricity | 279,571 kWh |
| Natural gas | 2,607 therms |
| Gross floor area | 50,104 sq ft |
| Source record | california:6283533:2024 |
The disclosure history
Year over year
| Year | Score | Δ | Site EUI | GHG emissions |
|---|---|---|---|---|
| 2024latest | 99 | +6 | 26.2 kBtu/ft² | 77 tCO₂e |
| 2022 | 93 | +17 | 32.9 kBtu/ft² | 112 tCO₂e |
| 2021 | 76 | +26 | 47.6 kBtu/ft² | 144 tCO₂e |
| 2020 | 50 | 69.3 kBtu/ft² | 227 tCO₂e | |
| 2019 | — | — | — | |
| 2018 | 50 | 69.5 kBtu/ft² | 234 tCO₂e |
Compliance context
AB 802 (Public Resources Code §25402.10)
AB 802 requires every California commercial building over 50,000 sq ft to report energy use to the CEC annually; the CEC publicly discloses the results statewide.
Ownership
No owning organisation shown. Names of private individuals in the disclosure are not published here.
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Location
- Address
- 306 Potrero Avenue, Sunnyvale
- City
- California
- State
- California
- ZIP
- 94085
- Coordinates
- 37.38645, -122.03776
Within ~1 km
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See also: most efficient in California · biggest emitters
How does 306-320 Potrero / 870 Hermosa compare with other office buildings in California?
The latest disclosures cover 6,214 office buildings in California, out of 40,029 buildings citywide. 306-320 Potrero / 870 Hermosa's ENERGY STAR score of 99 compares with an average of 75 across the 4,912 that report a score; it scores higher than 88% of them and lower than 9%. Its site EUI of 26.2 kBtu/ft² is about half of the average of 56.4 kBtu/ft² — it uses less energy per square foot than the typical building in that group. Its emissions intensity of 1.5 kgCO₂e/ft² is about 57% below the group average of 3.6 kgCO₂e/ft².
At 50,104 sq ft, it is about 67% below the average floor area of 151,937 sq ft for those buildings. It was built in 1972, 13 years earlier than the group's average year built (1985). 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 306-320 Potrero / 870 Hermosa's energy performance changed over time?
BuildingCensus holds 6 California disclosures for 306-320 Potrero / 870 Hermosa, covering report years 2018, 2019, 2020, 2021, 2022, 2024. Its ENERGY STAR score went from 50 in 2018 to 99 in 2024 (+49 points). Site EUI moved from 69.5 kBtu/ft² (2018) to 26.2 kBtu/ft² (2024), a 62% decrease. Reported emissions went from 234 tCO₂e to 77 tCO₂e over the same span (down 67%).
What does an ENERGY STAR score of 99 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 99 means the building performs better than about 99% of its national peers. BuildingCensus bands the score into report-card grades; 99 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 California, 65% 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. 306-320 Potrero / 870 Hermosa's 26.2 kBtu/ft² across 50,104 sq ft works out to about 1.3 billion Btu (385 MWh-equivalent) in 2024. The disclosure also reports 279,571 kWh of electricity and 2,607 therms of natural gas for the year.
Which law requires 306-320 Potrero / 870 Hermosa to report its energy use?
306-320 Potrero / 870 Hermosa reports under AB 802 (Public Resources Code §25402.10), the legal basis of California's Building Energy Benchmarking Program (statewide), which publishes each covered building's annual benchmarking results. The record shown here is the report-year 2024 disclosure (source record california:6283533:2024). AB 802 requires every California commercial building over 50,000 sq ft to report energy use to the CEC annually; the CEC publicly discloses the results statewide.
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Frequently asked questions
What is 306-320 Potrero / 870 Hermosa's energy grade?
306-320 Potrero / 870 Hermosa scores 99 out of 100 on ENERGY STAR — band A, high performer (85–100) — in its 2024 California disclosure. Scores are national percentiles against similar buildings; 75+ qualifies for ENERGY STAR certification.
How much energy does 306-320 Potrero / 870 Hermosa use?
Its 2024 site energy-use intensity was 26.2 kBtu/ft² across 50,104 sq ft, including 279,571 kWh of electricity and 2,607 therms of natural gas.
What are 306-320 Potrero / 870 Hermosa's carbon emissions?
306-320 Potrero / 870 Hermosa reported 77 tCO₂e of greenhouse-gas emissions (1.5 kgCO₂e/ft²) for 2024.
Where is 306-320 Potrero / 870 Hermosa?
306-320 Potrero / 870 Hermosa is at 306 Potrero Avenue, Sunnyvale, in Sunnyvale, California 94085. Its coordinates are 37.38645, -122.03776 (latitude, longitude), as published in the Building Energy Benchmarking Program (statewide) file.
How big is 306-320 Potrero / 870 Hermosa and when was it built?
306-320 Potrero / 870 Hermosa has 50,104 sq ft of gross floor area, as reported in its 2024 disclosure. The disclosure lists 1972 as its year built. It is classed as office.
Is 306-320 Potrero / 870 Hermosa covered by AB 802 (Public Resources Code §25402.10)?
Yes — it appears in the 2024 Building Energy Benchmarking Program (statewide) disclosure, which lists the buildings reporting under AB 802 (Public Resources Code §25402.10).
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About this data
Source: Building Energy Benchmarking Program (statewide) (AB 802 (Public Resources Code §25402.10)), as published July 9, 2026. See the methodology for how records are matched, cleaned and scored.
Cite as: BuildingCensus, “306-320 Potrero / 870 Hermosa, Sunnyvale, California — 2024 benchmarking disclosure”, https://buildingcensus.com/buildings/california/306-320-potrero-870-hermosa-21b11a23 (data as of July 9, 2026).