Clocktower Square Ii
Office in California, CA · 620 Hansen Way, Palo Alto · 94304
At a glance
Clocktower Square Ii is a 9,234-square-foot office building at 620 Hansen Way, Palo Alto in Palo Alto, California, built in 1983. In its 2021 California benchmarking disclosure it reported an ENERGY STAR score of 72 out of 100 (grade B) and 17 tCO₂e of greenhouse-gas emissions. That score is higher than 32% of the 4,912 scored office buildings in California.
AB 802 (Public Resources Code §25402.10) · reporting year 2021
Benchmarking record
| Field | Value |
|---|---|
| ENERGY STAR score | 72 (band B) |
| Site EUI | — |
| Source EUI | — |
| GHG emissions | 17 tCO₂e |
| GHG intensity | 1.9 kgCO₂e/ft² |
| Electricity | 83,152 kWh |
| Gross floor area | 9,234 sq ft |
| Source record | california:1412032:2021 |
The disclosure history
Year over year
| Year | Score | Δ | Site EUI | GHG emissions |
|---|---|---|---|---|
| 2021latest | 72 | +7 | — | 17 tCO₂e |
| 2020 | 65 | — | 18 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
- 620 Hansen Way, Palo Alto
- City
- California
- State
- California
- ZIP
- 94304
- Coordinates
- 37.41996, -122.13994
Within ~1 km
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See also: most efficient in California · biggest emitters
How does Clocktower Square Ii compare with other office buildings in California?
The latest disclosures cover 6,214 office buildings in California, out of 40,029 buildings citywide. Clocktower Square Ii's ENERGY STAR score of 72 compares with an average of 75 across the 4,912 that report a score; it scores higher than 32% of them and lower than 67%. Its emissions intensity of 1.9 kgCO₂e/ft² is about half of the group average of 3.6 kgCO₂e/ft².
At 9,234 sq ft, it is about 94% 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 Clocktower Square Ii's energy performance changed over time?
BuildingCensus holds 2 California disclosures for Clocktower Square Ii, covering report years 2020–2021. Its ENERGY STAR score went from 65 in 2020 to 72 in 2021 (+7 points). Reported emissions went from 18 tCO₂e to 17 tCO₂e over the same span (down 5%).
What does an ENERGY STAR score of 72 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 72 means the building performs better than about 72% of its national peers. BuildingCensus bands the score into report-card grades; 72 falls in band B — above median (70–84). It sits 3 points below 75, the threshold for ENERGY STAR certification. In California, 65% of scored buildings are at 75 or above.
Which law requires Clocktower Square Ii to report its energy use?
Clocktower Square Ii 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 2021 disclosure (source record california:1412032:2021). 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
- 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 Clocktower Square Ii's energy grade?
Clocktower Square Ii scores 72 out of 100 on ENERGY STAR — band B, above median (70–84) — in its 2021 California disclosure. Scores are national percentiles against similar buildings; 75+ qualifies for ENERGY STAR certification.
How much energy does Clocktower Square Ii use?
No energy-use intensity was reported for 2021.
What are Clocktower Square Ii's carbon emissions?
Clocktower Square Ii reported 17 tCO₂e of greenhouse-gas emissions (1.9 kgCO₂e/ft²) for 2021.
Where is Clocktower Square Ii?
Clocktower Square Ii is at 620 Hansen Way, Palo Alto, in Palo Alto, California 94304. Its coordinates are 37.41996, -122.13994 (latitude, longitude), as published in the Building Energy Benchmarking Program (statewide) file.
How big is Clocktower Square Ii and when was it built?
Clocktower Square Ii has 9,234 sq ft of gross floor area, as reported in its 2021 disclosure. The disclosure lists 1983 as its year built. It is classed as office.
Is Clocktower Square Ii covered by AB 802 (Public Resources Code §25402.10)?
Yes — it appears in the 2021 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, “Clocktower Square Ii, Palo Alto, California — 2021 benchmarking disclosure”, https://buildingcensus.com/buildings/california/clocktower-square-ii-2e5f9cad (data as of July 9, 2026).