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Sunnyside Senior Apartments (Sn019)

Multifamily Housing in California, CA · 251 South Walnut Avenue, San Dimas · 91773

At a glance

Sunnyside Senior Apartments (Sn019) is a 79,760-square-foot multifamily housing building at 251 South Walnut Avenue, San Dimas in San Dimas, California, built in 1983. In its 2024 California benchmarking disclosure it reported an ENERGY STAR score of 91 out of 100 (grade A), a site energy-use intensity of 51.5 kBtu/ft² and 244 tCO₂e of greenhouse-gas emissions. That score is higher than 49% of the 9,612 scored multifamily housing buildings in California.

ENERGY STAR score
91
band A · 2024
Site EUI
51.5
kBtu/ft²
GHG emissions
244
tCO₂e
GHG intensity
3.1
kgCO₂e/ft²
Floor area
79,760
sq ft
Year built
1983
vintage
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85–10070–8455–691–54
This entry + 6 nearby

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

Benchmarking record

FieldValue
ENERGY STAR score91 (band A)
Site EUI51.5 kBtu/ft²
Source EUI—
GHG emissions244 tCO₂e
GHG intensity3.1 kgCO₂e/ft²
Electricity479,104 kWh
Natural gas25,604 therms
Gross floor area79,760 sq ft
Source recordcalifornia:6766578:2024

The disclosure history

Year over year

YearScoreΔSite EUIGHG emissions
2024latest91±051.5 kBtu/ft²244 tCO₂e
202391-153.4 kBtu/ft²255 tCO₂e
202292+153.5 kBtu/ft²251 tCO₂e
202191+553.2 kBtu/ft²239 tCO₂e
202086+461.3 kBtu/ft²280 tCO₂e
20198259.3 kBtu/ft²284 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.

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Ownership

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

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Location

Address
251 South Walnut Avenue, San Dimas
State
California
ZIP
91773
Coordinates
34.10529, -117.80385

Within ~1 km

Nearby benchmarked buildings

See also: most efficient in California · biggest emitters

How does Sunnyside Senior Apartments (Sn019) 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. Sunnyside Senior Apartments (Sn019)'s ENERGY STAR score of 91 compares with an average of 82 across the 9,612 that report a score; it scores higher than 49% of them and lower than 49%. Its site EUI of 51.5 kBtu/ft² is about 50% 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 3.1 kgCO₂e/ft² is about 46% above the group average of 2.1 kgCO₂e/ft².

At 79,760 sq ft, it is about half of the average floor area of 150,919 sq ft for those buildings. It was built in 1983, 5 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 Sunnyside Senior Apartments (Sn019)'s energy performance changed over time?

BuildingCensus holds 6 California disclosures for Sunnyside Senior Apartments (Sn019), covering report years 2019–2024. Its ENERGY STAR score went from 82 in 2019 to 91 in 2024 (+9 points); its best year on file was 2022, at 92. Site EUI moved from 59.3 kBtu/ft² (2019) to 51.5 kBtu/ft² (2024), a 13% decrease. Reported emissions went from 284 tCO₂e to 244 tCO₂e over the same span (down 14%).

What does an ENERGY STAR score of 91 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 91 means the building performs better than about 91% of its national peers. BuildingCensus bands the score into report-card grades; 91 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. Sunnyside Senior Apartments (Sn019)'s 51.5 kBtu/ft² across 79,760 sq ft works out to about 4.1 billion Btu (1,204 MWh-equivalent) in 2024. The disclosure also reports 479,104 kWh of electricity and 25,604 therms of natural gas for the year.

Which law requires Sunnyside Senior Apartments (Sn019) to report its energy use?

Sunnyside Senior Apartments (Sn019) 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:6766578:2024). 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 Sunnyside Senior Apartments (Sn019)'s energy grade?

Sunnyside Senior Apartments (Sn019) scores 91 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 Sunnyside Senior Apartments (Sn019) use?

Its 2024 site energy-use intensity was 51.5 kBtu/ft² across 79,760 sq ft, including 479,104 kWh of electricity and 25,604 therms of natural gas.

What are Sunnyside Senior Apartments (Sn019)'s carbon emissions?

Sunnyside Senior Apartments (Sn019) reported 244 tCO₂e of greenhouse-gas emissions (3.1 kgCO₂e/ft²) for 2024.

Where is Sunnyside Senior Apartments (Sn019)?

Sunnyside Senior Apartments (Sn019) is at 251 South Walnut Avenue, San Dimas, in San Dimas, California 91773. Its coordinates are 34.10529, -117.80385 (latitude, longitude), as published in the Building Energy Benchmarking Program (statewide) file.

How big is Sunnyside Senior Apartments (Sn019) and when was it built?

Sunnyside Senior Apartments (Sn019) has 79,760 sq ft of gross floor area, as reported in its 2024 disclosure. The disclosure lists 1983 as its year built. It is classed as multifamily housing.

Is Sunnyside Senior Apartments (Sn019) 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, “Sunnyside Senior Apartments (Sn019), San Dimas, California — 2024 benchmarking disclosure”, https://buildingcensus.com/buildings/california/sunnyside-senior-apartments-sn019-12875704 (data as of July 9, 2026).