21700 Gateway Corporate Center
Office in California, CA · 21700 Copley Drive, Diamond Bar · 91765
At a glance
21700 Gateway Corporate Center is a 77,731-square-foot office building at 21700 Copley Drive, Diamond Bar in Diamond Bar, California, built in 1988. In its 2024 California benchmarking disclosure it reported an ENERGY STAR score of 94 out of 100 (grade A), a site energy-use intensity of 28.4 kBtu/ft² and 142 tCO₂e of greenhouse-gas emissions. That score is higher than 75% 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 | 94 (band A) |
| Site EUI | 28.4 kBtu/ft² |
| Source EUI | — |
| GHG emissions | 142 tCO₂e |
| GHG intensity | 1.8 kgCO₂e/ft² |
| Electricity | 627,340 kWh |
| Gross floor area | 77,731 sq ft |
| Source record | california:3995474:2024 |
The disclosure history
Year over year
| Year | Score | Δ | Site EUI | GHG emissions |
|---|---|---|---|---|
| 2024latest | 94 | ±0 | 28.4 kBtu/ft² | 142 tCO₂e |
| 2023 | 94 | +3 | 27.8 kBtu/ft² | 153 tCO₂e |
| 2020 | 91 | +1 | 30.6 kBtu/ft² | 158 tCO₂e |
| 2019 | 90 | +4 | 36.0 kBtu/ft² | 196 tCO₂e |
| 2018 | 86 | 40.3 kBtu/ft² | 221 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
- 21700 Copley Drive, Diamond Bar
- City
- California
- State
- California
- ZIP
- 91765
- Coordinates
- 33.99858, -117.83217
Within ~1 km
Nearby benchmarked buildings
- Holiday Inn Diamond Barscore 100
Hotel · 158,400 sq ft
- Niagara Bottling, Llc- Hqscore —
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- Gateway Corporate Center Lpscore —
Office · 85,216 sq ft
- Senita Gateway Center Bscore 81
Office · 83,085 sq ft
- Senita Gateway Center Ascore 85
Office · 80,950 sq ft
- 21680 Gateway Centerscore —
Office · 80,753 sq ft
See also: most efficient in California · biggest emitters
How does 21700 Gateway Corporate Center compare with other office buildings in California?
The latest disclosures cover 6,214 office buildings in California, out of 40,029 buildings citywide. 21700 Gateway Corporate Center's ENERGY STAR score of 94 compares with an average of 75 across the 4,912 that report a score; it scores higher than 75% of them and lower than 22%. Its site EUI of 28.4 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 1.8 kgCO₂e/ft² is about half of the group average of 3.6 kgCO₂e/ft².
At 77,731 sq ft, it is about half of the average floor area of 151,937 sq ft for those buildings. It was built in 1988, 3 years later 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 21700 Gateway Corporate Center's energy performance changed over time?
BuildingCensus holds 5 California disclosures for 21700 Gateway Corporate Center, covering report years 2018, 2019, 2020, 2023, 2024. Its ENERGY STAR score went from 86 in 2018 to 94 in 2024 (+8 points); its best year on file was 2023, at 94. Site EUI moved from 40.3 kBtu/ft² (2018) to 28.4 kBtu/ft² (2024), a 30% decrease. Reported emissions went from 221 tCO₂e to 142 tCO₂e over the same span (down 36%).
What does an ENERGY STAR score of 94 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 94 means the building performs better than about 94% of its national peers. BuildingCensus bands the score into report-card grades; 94 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. 21700 Gateway Corporate Center's 28.4 kBtu/ft² across 77,731 sq ft works out to about 2.2 billion Btu (647 MWh-equivalent) in 2024. The disclosure also reports 627,340 kWh of electricity for the year.
Which law requires 21700 Gateway Corporate Center to report its energy use?
21700 Gateway Corporate Center 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:3995474:2024). 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.
More office buildings in California
- Ph - Environmental Health Headquarters (Ab 802)· 77,700 sq ft · score 58 (C)
- 3307 Hillview Avenue· 77,661 sq ft · EUI 73.1 kBtu/ft²
- 12 Mf (Batavia Maintenance Station)· 77,653 sq ft · score 99 (A)
- 1450 Page Mill Road· 77,634 sq ft · EUI 31.2 kBtu/ft²
- 2875 Michelle· 77,625 sq ft · score 62 (C)
- 14000 Jamboree· 77,625 sq ft · EUI 116.3 kBtu/ft²
- Office buildings in California· 6,214 benchmarked
- All California benchmarked buildings· AB 802 (Public Resources Code §25402.10)
- Most efficient large buildings in California
- Least efficient large buildings in California
- Biggest emitters in California
Frequently asked questions
What is 21700 Gateway Corporate Center's energy grade?
21700 Gateway Corporate Center scores 94 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 21700 Gateway Corporate Center use?
Its 2024 site energy-use intensity was 28.4 kBtu/ft² across 77,731 sq ft, including 627,340 kWh of electricity.
What are 21700 Gateway Corporate Center's carbon emissions?
21700 Gateway Corporate Center reported 142 tCO₂e of greenhouse-gas emissions (1.8 kgCO₂e/ft²) for 2024.
Where is 21700 Gateway Corporate Center?
21700 Gateway Corporate Center is at 21700 Copley Drive, Diamond Bar, in Diamond Bar, California 91765. Its coordinates are 33.99858, -117.83217 (latitude, longitude), as published in the Building Energy Benchmarking Program (statewide) file.
How big is 21700 Gateway Corporate Center and when was it built?
21700 Gateway Corporate Center has 77,731 sq ft of gross floor area, as reported in its 2024 disclosure. The disclosure lists 1988 as its year built. It is classed as office.
Is 21700 Gateway Corporate Center 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, “21700 Gateway Corporate Center, Diamond Bar, California — 2024 benchmarking disclosure”, https://buildingcensus.com/buildings/california/21700-gateway-corporate-center-ce44d05a (data as of July 9, 2026).