401 Ellis
Office in California, CA · 401 Ellis Street, Mountain View · 94043
At a glance
401 Ellis is a 100,842-square-foot office building at 401 Ellis Street, Mountain View in Mountain View, California, built in 1998. In its 2024 California benchmarking disclosure it reported an ENERGY STAR score of 100 out of 100 (grade A), a site energy-use intensity of 9.8 kBtu/ft² and 49 tCO₂e of greenhouse-gas emissions. That score is higher than 91% 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 | 100 (band A) |
| Site EUI | 9.8 kBtu/ft² |
| Source EUI | — |
| GHG emissions | 49 tCO₂e |
| GHG intensity | 0.5 kgCO₂e/ft² |
| Electricity | 250,721 kWh |
| Natural gas | 8 therms |
| Gross floor area | 100,842 sq ft |
| Source record | california:15619761:2024 |
The disclosure history
Year over year
| Year | Score | Δ | Site EUI | GHG emissions |
|---|---|---|---|---|
| 2024latest | 100 | +1 | 9.8 kBtu/ft² | 49 tCO₂e |
| 2023 | 99 | 20.7 kBtu/ft² | 166 tCO₂e | |
| 2020 | — | — | — |
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
- 401 Ellis Street, Mountain View
- City
- California
- State
- California
- ZIP
- 94043
- Coordinates
- 37.39815, -122.05236
Within ~1 km
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- 380 Ellis Streetscore —
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See also: most efficient in California · biggest emitters
How does 401 Ellis compare with other office buildings in California?
The latest disclosures cover 6,214 office buildings in California, out of 40,029 buildings citywide. 401 Ellis's ENERGY STAR score of 100 compares with an average of 75 across the 4,912 that report a score; it scores higher than 91% of them. Its site EUI of 9.8 kBtu/ft² is about 83% below 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 0.5 kgCO₂e/ft² is about 86% below the group average of 3.6 kgCO₂e/ft².
At 100,842 sq ft, it is about 34% below the average floor area of 151,937 sq ft for those buildings. It was built in 1998, 13 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 401 Ellis's energy performance changed over time?
BuildingCensus holds 3 California disclosures for 401 Ellis, covering report years 2020, 2023, 2024. Its ENERGY STAR score went from 99 in 2023 to 100 in 2024 (+1 points). Site EUI moved from 20.7 kBtu/ft² (2023) to 9.8 kBtu/ft² (2024), a 53% decrease. Reported emissions went from 166 tCO₂e to 49 tCO₂e over the same span (down 71%).
What does an ENERGY STAR score of 100 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: 100 is the top of the scale. BuildingCensus bands the score into report-card grades; 100 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. 401 Ellis's 9.8 kBtu/ft² across 100,842 sq ft works out to about 1 billion Btu (290 MWh-equivalent) in 2024. The disclosure also reports 250,721 kWh of electricity and 8 therms of natural gas for the year.
Which law requires 401 Ellis to report its energy use?
401 Ellis 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:15619761:2024). 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
- 2377, 2377 Crenshaw Boulevard, Torrance· 100,815 sq ft · score 98 (A)
- Prospect Point I - 11050 Olson· 100,811 sq ft · score 100 (A)
- 4311 Wilshire, Llc· 100,805 sq ft · score 85 (A)
- 742 S Hill St· 100,800 sq ft · score 100 (A)
- Embarcadero Corporate Center· 100,734 sq ft · EUI 66.4 kBtu/ft²
- Lake Park Business Center - Bldg 2 3003· 100,729 sq ft · score 73 (B)
- 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 401 Ellis's energy grade?
401 Ellis scores 100 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 401 Ellis use?
Its 2024 site energy-use intensity was 9.8 kBtu/ft² across 100,842 sq ft, including 250,721 kWh of electricity and 8 therms of natural gas.
What are 401 Ellis's carbon emissions?
401 Ellis reported 49 tCO₂e of greenhouse-gas emissions (0.5 kgCO₂e/ft²) for 2024.
Where is 401 Ellis?
401 Ellis is at 401 Ellis Street, Mountain View, in Mountain View, California 94043. Its coordinates are 37.39815, -122.05236 (latitude, longitude), as published in the Building Energy Benchmarking Program (statewide) file.
How big is 401 Ellis and when was it built?
401 Ellis has 100,842 sq ft of gross floor area, as reported in its 2024 disclosure. The disclosure lists 1998 as its year built. It is classed as office.
Is 401 Ellis 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, “401 Ellis, Mountain View, California — 2024 benchmarking disclosure”, https://buildingcensus.com/buildings/california/401-ellis-8e5e9efc (data as of July 9, 2026).