2185 Mt. Diablo Plaza
Office in California, CA · 2185 North California Boulevard, Walnut Creek · 94596
At a glance
2185 Mt. Diablo Plaza is a 128,626-square-foot office building at 2185 North California Boulevard, Walnut Creek in Walnut Creek, California, built in 1983. In its 2024 California benchmarking disclosure it reported an ENERGY STAR score of 91 out of 100 (grade A), a site energy-use intensity of 31.0 kBtu/ft² and 249 tCO₂e of greenhouse-gas emissions. That score is higher than 66% 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 | 91 (band A) |
| Site EUI | 31.0 kBtu/ft² |
| Source EUI | — |
| GHG emissions | 249 tCO₂e |
| GHG intensity | 1.9 kgCO₂e/ft² |
| Electricity | 696,441 kWh |
| Natural gas | 17,157 therms |
| Gross floor area | 128,626 sq ft |
| Source record | california:1033923:2024 |
The disclosure history
Year over year
| Year | Score | Δ | Site EUI | GHG emissions |
|---|---|---|---|---|
| 2024latest | 91 | -2 | 31.0 kBtu/ft² | 249 tCO₂e |
| 2023 | 93 | ±0 | 39.4 kBtu/ft² | 332 tCO₂e |
| 2022 | 93 | +1 | 38.4 kBtu/ft² | 317 tCO₂e |
| 2021 | 92 | +3 | 42.6 kBtu/ft² | 291 tCO₂e |
| 2020 | 89 | +12 | 52.6 kBtu/ft² | 343 tCO₂e |
| 2018 | 77 | 58.4 kBtu/ft² | 455 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.
Own or manage this building? Claim it to correct the record and get compliance alerts.
Location
- Address
- 2185 North California Boulevard, Walnut Creek
- City
- California
- State
- California
- ZIP
- 94596
- Coordinates
- 37.90950, -122.06625
Within ~1 km
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- The Waymark (Wy053) (Not)score —
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See also: most efficient in California · biggest emitters
How does 2185 Mt. Diablo Plaza compare with other office buildings in California?
The latest disclosures cover 6,214 office buildings in California, out of 40,029 buildings citywide. 2185 Mt. Diablo Plaza's ENERGY STAR score of 91 compares with an average of 75 across the 4,912 that report a score; it scores higher than 66% of them and lower than 31%. Its site EUI of 31.0 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 1.9 kgCO₂e/ft² is about half of the group average of 3.6 kgCO₂e/ft².
At 128,626 sq ft, it is about 15% below the average floor area of 151,937 sq ft for those buildings. Its 1983 construction date is close to 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 2185 Mt. Diablo Plaza's energy performance changed over time?
BuildingCensus holds 6 California disclosures for 2185 Mt. Diablo Plaza, covering report years 2018, 2020, 2021, 2022, 2023, 2024. Its ENERGY STAR score went from 77 in 2018 to 91 in 2024 (+14 points); its best year on file was 2022, at 93. Site EUI moved from 58.4 kBtu/ft² (2018) to 31.0 kBtu/ft² (2024), a 47% decrease. Reported emissions went from 455 tCO₂e to 249 tCO₂e over the same span (down 45%).
What does an ENERGY STAR score of 91 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 91 means the building performs better than about 91% of its national peers. BuildingCensus bands the score into report-card grades; 91 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. 2185 Mt. Diablo Plaza's 31.0 kBtu/ft² across 128,626 sq ft works out to about 4 billion Btu (1,169 MWh-equivalent) in 2024. The disclosure also reports 696,441 kWh of electricity and 17,157 therms of natural gas for the year.
Which law requires 2185 Mt. Diablo Plaza to report its energy use?
2185 Mt. Diablo Plaza 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:1033923:2024). 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
- 2235 Mercury Way· 128,546 sq ft · score 81 (B)
- 5200, 2903 & 2933 Bunker Hill Lane And 5200 Great America Parkway, Santa Clara· 128,541 sq ft
- 1 Pointe· 128,447 sq ft · score 97 (A)
- 3068 Kilgore Road - Rancho Cordova· 128,406 sq ft · score 88 (A)
- 3416 La Cienga Boulevard· 128,353 sq ft · score 21 (D)
- Moorpark Business Center· 128,276 sq ft · score 22 (D)
- 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 2185 Mt. Diablo Plaza's energy grade?
2185 Mt. Diablo Plaza scores 91 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 2185 Mt. Diablo Plaza use?
Its 2024 site energy-use intensity was 31.0 kBtu/ft² across 128,626 sq ft, including 696,441 kWh of electricity and 17,157 therms of natural gas.
What are 2185 Mt. Diablo Plaza's carbon emissions?
2185 Mt. Diablo Plaza reported 249 tCO₂e of greenhouse-gas emissions (1.9 kgCO₂e/ft²) for 2024.
Where is 2185 Mt. Diablo Plaza?
2185 Mt. Diablo Plaza is at 2185 North California Boulevard, Walnut Creek, in Walnut Creek, California 94596. Its coordinates are 37.90950, -122.06625 (latitude, longitude), as published in the Building Energy Benchmarking Program (statewide) file.
How big is 2185 Mt. Diablo Plaza and when was it built?
2185 Mt. Diablo Plaza has 128,626 sq ft of gross floor area, as reported in its 2024 disclosure. The disclosure lists 1983 as its year built. It is classed as office.
Is 2185 Mt. Diablo Plaza 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, “2185 Mt. Diablo Plaza, Walnut Creek, California — 2024 benchmarking disclosure”, https://buildingcensus.com/buildings/california/2185-mt-diablo-plaza-1a657556 (data as of July 9, 2026).