121 Theory
Office in California, CA · 121 Theory, Irvine · 92617
At a glance
121 Theory is a 63,440-square-foot office building at 121 Theory, Irvine in Irvine, California, built in 1999. In its 2024 California benchmarking disclosure it reported an ENERGY STAR score of 63 out of 100 (grade C), a site energy-use intensity of 52.4 kBtu/ft² and 211 tCO₂e of greenhouse-gas emissions. That score is higher than 24% 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 | 63 (band C) |
| Site EUI | 52.4 kBtu/ft² |
| Source EUI | — |
| GHG emissions | 211 tCO₂e |
| GHG intensity | 3.3 kgCO₂e/ft² |
| Electricity | 755,005 kWh |
| Natural gas | 7,462 therms |
| Gross floor area | 63,440 sq ft |
| Source record | california:4325273:2024 |
The disclosure history
Year over year
| Year | Score | Δ | Site EUI | GHG emissions |
|---|---|---|---|---|
| 2024latest | 63 | +13 | 52.4 kBtu/ft² | 211 tCO₂e |
| 2023 | 50 | +10 | 60.3 kBtu/ft² | 258 tCO₂e |
| 2022 | 40 | +10 | 62.7 kBtu/ft² | 273 tCO₂e |
| 2021 | 30 | +8 | 80.6 kBtu/ft² | 299 tCO₂e |
| 2020 | 22 | +8 | 89.2 kBtu/ft² | 354 tCO₂e |
| 2019 | 14 | +3 | 100.3 kBtu/ft² | 426 tCO₂e |
| 2018 | 11 | 106.3 kBtu/ft² | 453 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
- 121 Theory, Irvine
- City
- California
- State
- California
- ZIP
- 92617
- Coordinates
- 33.64254, -117.85725
Within ~1 km
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See also: most efficient in California · biggest emitters
How does 121 Theory compare with other office buildings in California?
The latest disclosures cover 6,214 office buildings in California, out of 40,029 buildings citywide. 121 Theory's ENERGY STAR score of 63 compares with an average of 75 across the 4,912 that report a score; it scores higher than 24% of them and lower than 75%. Its site EUI of 52.4 kBtu/ft² is roughly in line with 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 3.3 kgCO₂e/ft² is roughly in line with the group average of 3.6 kgCO₂e/ft².
At 63,440 sq ft, it is about 58% below the average floor area of 151,937 sq ft for those buildings. It was built in 1999, 14 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 121 Theory's energy performance changed over time?
BuildingCensus holds 7 California disclosures for 121 Theory, covering report years 2018–2024. Its ENERGY STAR score went from 11 in 2018 to 63 in 2024 (+52 points). Site EUI moved from 106.3 kBtu/ft² (2018) to 52.4 kBtu/ft² (2024), a 51% decrease. Reported emissions went from 453 tCO₂e to 211 tCO₂e over the same span (down 54%).
What does an ENERGY STAR score of 63 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 63 means the building performs better than about 63% of its national peers. BuildingCensus bands the score into report-card grades; 63 falls in band C — below median (55–69). It sits 12 points below 75, the threshold for ENERGY STAR certification. 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. 121 Theory's 52.4 kBtu/ft² across 63,440 sq ft works out to about 3.3 billion Btu (974 MWh-equivalent) in 2024. The disclosure also reports 755,005 kWh of electricity and 7,462 therms of natural gas for the year.
Which law requires 121 Theory to report its energy use?
121 Theory 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:4325273:2024). 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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- Office buildings in California· 6,214 benchmarked
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- Least efficient large buildings in California
- Biggest emitters in California
Frequently asked questions
What is 121 Theory's energy grade?
121 Theory scores 63 out of 100 on ENERGY STAR — band C, below median (55–69) — in its 2024 California disclosure. Scores are national percentiles against similar buildings; 75+ qualifies for ENERGY STAR certification.
How much energy does 121 Theory use?
Its 2024 site energy-use intensity was 52.4 kBtu/ft² across 63,440 sq ft, including 755,005 kWh of electricity and 7,462 therms of natural gas.
What are 121 Theory's carbon emissions?
121 Theory reported 211 tCO₂e of greenhouse-gas emissions (3.3 kgCO₂e/ft²) for 2024.
Where is 121 Theory?
121 Theory is at 121 Theory, Irvine, in Irvine, California 92617. Its coordinates are 33.64254, -117.85725 (latitude, longitude), as published in the Building Energy Benchmarking Program (statewide) file.
How big is 121 Theory and when was it built?
121 Theory has 63,440 sq ft of gross floor area, as reported in its 2024 disclosure. The disclosure lists 1999 as its year built. It is classed as office.
Is 121 Theory 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, “121 Theory, Irvine, California — 2024 benchmarking disclosure”, https://buildingcensus.com/buildings/california/121-theory-b779c605 (data as of July 9, 2026).