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Walnut Heights Apartments - Essex (Wl290)

Multifamily Housing in California, CA · 20700 San Jose Hills Road, Walnut · 91789

At a glance

Walnut Heights Apartments - Essex (Wl290) is a 150,207-square-foot multifamily housing building at 20700 San Jose Hills Road, Walnut in Walnut, California, built in 1964. 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 41.4 kBtu/ft² and 347 tCO₂e of greenhouse-gas emissions. That score is higher than 55% of the 9,612 scored multifamily housing buildings in California.

ENERGY STAR score
94
band A · 2024
Site EUI
41.4
kBtu/ft²
GHG emissions
347
tCO₂e
GHG intensity
2.3
kgCO₂e/ft²
Floor area
150,207
sq ft
Year built
1964
vintage
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85–10070–8455–691–54
This entry + 2 nearby

AB 802 (Public Resources Code §25402.10) · reporting year 2024

Benchmarking record

FieldValue
ENERGY STAR score94 (band A)
Site EUI41.4 kBtu/ft²
Source EUI—
GHG emissions347 tCO₂e
GHG intensity2.3 kgCO₂e/ft²
Electricity734,992 kWh
Natural gas38,348 therms
Gross floor area150,207 sq ft
Source recordcalifornia:6780517:2024

The disclosure history

Year over year

YearScoreΔSite EUIGHG emissions
2024latest94+841.4 kBtu/ft²347 tCO₂e
202386+342.6 kBtu/ft²382 tCO₂e
202283+544.0 kBtu/ft²401 tCO₂e
202178-548.3 kBtu/ft²405 tCO₂e
202083-645.9 kBtu/ft²407 tCO₂e
20198942.8 kBtu/ft²382 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.

Program details →

Ownership

No owning organisation shown. Names of private individuals in the disclosure are not published here.

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Location

Address
20700 San Jose Hills Road, Walnut
State
California
ZIP
91789
Coordinates
34.04421, -117.85012

Within ~1 km

Nearby benchmarked buildings

See also: most efficient in California · biggest emitters

How does Walnut Heights Apartments - Essex (Wl290) compare with other multifamily housing buildings in California?

The latest disclosures cover 10,630 multifamily housing buildings in California, out of 40,029 buildings citywide. Walnut Heights Apartments - Essex (Wl290)'s ENERGY STAR score of 94 compares with an average of 82 across the 9,612 that report a score; it scores higher than 55% of them and lower than 42%. Its site EUI of 41.4 kBtu/ft² is about 20% above the average of 34.4 kBtu/ft² — it uses more energy per square foot than the typical building in that group. Its emissions intensity of 2.3 kgCO₂e/ft² is about 10% above the group average of 2.1 kgCO₂e/ft².

At 150,207 sq ft, it is roughly in line with the average floor area of 150,919 sq ft for those buildings. It was built in 1964, 24 years earlier than the group's average year built (1988). Across all 24 jurisdictions BuildingCensus covers, the 59,945 multifamily housing buildings average an ENERGY STAR score of 70 and a site EUI of 59.0 kBtu/ft².

How has Walnut Heights Apartments - Essex (Wl290)'s energy performance changed over time?

BuildingCensus holds 6 California disclosures for Walnut Heights Apartments - Essex (Wl290), covering report years 2019–2024. Its ENERGY STAR score went from 89 in 2019 to 94 in 2024 (+5 points). Site EUI moved from 42.8 kBtu/ft² (2019) to 41.4 kBtu/ft² (2024), a 3% decrease. Reported emissions went from 382 tCO₂e to 347 tCO₂e over the same span (down 9%).

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. Walnut Heights Apartments - Essex (Wl290)'s 41.4 kBtu/ft² across 150,207 sq ft works out to about 6.2 billion Btu (1,822 MWh-equivalent) in 2024. The disclosure also reports 734,992 kWh of electricity and 38,348 therms of natural gas for the year.

Which law requires Walnut Heights Apartments - Essex (Wl290) to report its energy use?

Walnut Heights Apartments - Essex (Wl290) 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:6780517:2024). 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 multifamily housing buildings in California

Frequently asked questions

What is Walnut Heights Apartments - Essex (Wl290)'s energy grade?

Walnut Heights Apartments - Essex (Wl290) 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 Walnut Heights Apartments - Essex (Wl290) use?

Its 2024 site energy-use intensity was 41.4 kBtu/ft² across 150,207 sq ft, including 734,992 kWh of electricity and 38,348 therms of natural gas.

What are Walnut Heights Apartments - Essex (Wl290)'s carbon emissions?

Walnut Heights Apartments - Essex (Wl290) reported 347 tCO₂e of greenhouse-gas emissions (2.3 kgCO₂e/ft²) for 2024.

Where is Walnut Heights Apartments - Essex (Wl290)?

Walnut Heights Apartments - Essex (Wl290) is at 20700 San Jose Hills Road, Walnut, in Walnut, California 91789. Its coordinates are 34.04421, -117.85012 (latitude, longitude), as published in the Building Energy Benchmarking Program (statewide) file.

How big is Walnut Heights Apartments - Essex (Wl290) and when was it built?

Walnut Heights Apartments - Essex (Wl290) has 150,207 sq ft of gross floor area, as reported in its 2024 disclosure. The disclosure lists 1964 as its year built. It is classed as multifamily housing.

Is Walnut Heights Apartments - Essex (Wl290) 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, “Walnut Heights Apartments - Essex (Wl290), Walnut, California — 2024 benchmarking disclosure”, https://buildingcensus.com/buildings/california/walnut-heights-apartments-essex-wl290-9928532f (data as of July 9, 2026).