2175 Mt. Diablo Plaza
Office in California, CA · 2175 North California Boulevard, Walnut Creek · 94596
At a glance
2175 Mt. Diablo Plaza is a 204,571-square-foot office building at 2175 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 94 out of 100 (grade A), a site energy-use intensity of 28.7 kBtu/ft² and 364 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 | 28.7 kBtu/ft² |
| Source EUI | — |
| GHG emissions | 364 tCO₂e |
| GHG intensity | 1.8 kgCO₂e/ft² |
| Electricity | 1,013,997 kWh |
| Natural gas | 25,368 therms |
| Gross floor area | 204,571 sq ft |
| Source record | california:1033920:2024 |
The disclosure history
Year over year
| Year | Score | Δ | Site EUI | GHG emissions |
|---|---|---|---|---|
| 2024latest | 94 | +1 | 28.7 kBtu/ft² | 364 tCO₂e |
| 2023 | 93 | ±0 | 34.2 kBtu/ft² | 496 tCO₂e |
| 2022 | 93 | ±0 | 33.6 kBtu/ft² | 481 tCO₂e |
| 2021 | 93 | ±0 | 38.0 kBtu/ft² | 454 tCO₂e |
| 2020 | 93 | +11 | 41.2 kBtu/ft² | 485 tCO₂e |
| 2018 | 82 | 53.0 kBtu/ft² | 726 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
- 2175 North California Boulevard, Walnut Creek
- City
- California
- State
- California
- ZIP
- 94596
- Coordinates
- 37.90899, -122.06602
Within ~1 km
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See also: most efficient in California · biggest emitters
How does 2175 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. 2175 Mt. Diablo Plaza'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 28.7 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 204,571 sq ft, it is about 35% above 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 2175 Mt. Diablo Plaza's energy performance changed over time?
BuildingCensus holds 6 California disclosures for 2175 Mt. Diablo Plaza, covering report years 2018, 2020, 2021, 2022, 2023, 2024. Its ENERGY STAR score went from 82 in 2018 to 94 in 2024 (+12 points). Site EUI moved from 53.0 kBtu/ft² (2018) to 28.7 kBtu/ft² (2024), a 46% decrease. Reported emissions went from 726 tCO₂e to 364 tCO₂e over the same span (down 50%).
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. 2175 Mt. Diablo Plaza's 28.7 kBtu/ft² across 204,571 sq ft works out to about 5.9 billion Btu (1,721 MWh-equivalent) in 2024. The disclosure also reports 1,013,997 kWh of electricity and 25,368 therms of natural gas for the year.
Which law requires 2175 Mt. Diablo Plaza to report its energy use?
2175 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:1033920:2024). 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
- 795 Folsom Street· 204,560 sq ft · score 91 (A)
- Trea - Pacific Coast Highway Llc· 204,411 sq ft · score 62 (C)
- 353 W Julian· 204,000 sq ft · score 91 (A)
- 310 & 342 N. San Fernando Rd. - Ladbs· 204,000 sq ft · score 84 (B)
- 6100 W. Wilshire Blvd. - Ladbs· 203,960 sq ft · score 75 (B)
- T20 2 N Lake Ave Pasadena 91101· 203,911 sq ft · score 93 (A)
- 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 2175 Mt. Diablo Plaza's energy grade?
2175 Mt. Diablo Plaza 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 2175 Mt. Diablo Plaza use?
Its 2024 site energy-use intensity was 28.7 kBtu/ft² across 204,571 sq ft, including 1,013,997 kWh of electricity and 25,368 therms of natural gas.
What are 2175 Mt. Diablo Plaza's carbon emissions?
2175 Mt. Diablo Plaza reported 364 tCO₂e of greenhouse-gas emissions (1.8 kgCO₂e/ft²) for 2024.
Where is 2175 Mt. Diablo Plaza?
2175 Mt. Diablo Plaza is at 2175 North California Boulevard, Walnut Creek, in Walnut Creek, California 94596. Its coordinates are 37.90899, -122.06602 (latitude, longitude), as published in the Building Energy Benchmarking Program (statewide) file.
How big is 2175 Mt. Diablo Plaza and when was it built?
2175 Mt. Diablo Plaza has 204,571 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 2175 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, “2175 Mt. Diablo Plaza, Walnut Creek, California — 2024 benchmarking disclosure”, https://buildingcensus.com/buildings/california/2175-mt-diablo-plaza-98066989 (data as of July 9, 2026).