Windsor Manor Iii
Multifamily Housing in California, CA · 535 Autumn Drive, San Marcos · 92069
At a glance
Windsor Manor Iii is a 52,000-square-foot multifamily housing building at 535 Autumn Drive, San Marcos in San Marcos, California, built in 1984. In its 2024 California benchmarking disclosure it reported an ENERGY STAR score of 76 out of 100 (grade B), a site energy-use intensity of 35.2 kBtu/ft² and 111 tCO₂e of greenhouse-gas emissions. That score is higher than 28% of the 9,612 scored multifamily housing buildings in California.
AB 802 (Public Resources Code §25402.10) · reporting year 2024
Benchmarking record
| Field | Value |
|---|---|
| ENERGY STAR score | 76 (band B) |
| Site EUI | 35.2 kBtu/ft² |
| Source EUI | — |
| GHG emissions | 111 tCO₂e |
| GHG intensity | 2.1 kgCO₂e/ft² |
| Electricity | 203,146 kWh |
| Natural gas | 12,201 therms |
| Gross floor area | 52,000 sq ft |
| Source record | california:16068231:2024 |
The disclosure history
Year over year
| Year | Score | Δ | Site EUI | GHG emissions |
|---|---|---|---|---|
| 2024latest | 76 | +24 | 35.2 kBtu/ft² | 111 tCO₂e |
| 2021 | 52 | 41.3 kBtu/ft² | 121 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
- 535 Autumn Drive, San Marcos
- City
- California
- State
- California
- ZIP
- 92069
- Coordinates
- 33.14413, -117.17334
Within ~1 km
Nearby benchmarked buildings
- Windsor Manor Iscore 100
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- Renaissance Villas Apartmentsscore 100
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- San Marcos Middle Schoolscore 65
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- 6656 - San Marcosscore 8
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- Fairfield By Marriott San Marcosscore 100
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See also: most efficient in California · biggest emitters
How does Windsor Manor Iii 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. Windsor Manor Iii's ENERGY STAR score of 76 compares with an average of 82 across the 9,612 that report a score; it scores higher than 28% of them and lower than 71%. Its site EUI of 35.2 kBtu/ft² is roughly in line with the average of 34.4 kBtu/ft². Its emissions intensity of 2.1 kgCO₂e/ft² is roughly in line with the group average of 2.1 kgCO₂e/ft².
At 52,000 sq ft, it is about 66% below the average floor area of 150,919 sq ft for those buildings. It was built in 1984, 4 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 Windsor Manor Iii's energy performance changed over time?
BuildingCensus holds 2 California disclosures for Windsor Manor Iii, covering report years 2021, 2024. Its ENERGY STAR score went from 52 in 2021 to 76 in 2024 (+24 points). Site EUI moved from 41.3 kBtu/ft² (2021) to 35.2 kBtu/ft² (2024), a 15% decrease. Reported emissions went from 121 tCO₂e to 111 tCO₂e over the same span (down 8%).
What does an ENERGY STAR score of 76 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 76 means the building performs better than about 76% of its national peers. BuildingCensus bands the score into report-card grades; 76 falls in band B — above median (70–84). 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. Windsor Manor Iii's 35.2 kBtu/ft² across 52,000 sq ft works out to about 1.8 billion Btu (536 MWh-equivalent) in 2024. The disclosure also reports 203,146 kWh of electricity and 12,201 therms of natural gas for the year.
Which law requires Windsor Manor Iii to report its energy use?
Windsor Manor Iii 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:16068231:2024). 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
- Parkway Plaza Apartments· 51,974 sq ft · EUI 22.3 kBtu/ft²
- Ca571_Building D· 51,974 sq ft · score 94 (A)
- Village Green· 51,968 sq ft · score 17 (D)
- Gateway Court Apartments· 51,952 sq ft · score 100 (A)
- Ca571_Building H· 51,951 sq ft · score 93 (A)
- Curtner Studios· 51,940 sq ft · score 93 (A)
- Multifamily Housing buildings in California· 10,630 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 Windsor Manor Iii's energy grade?
Windsor Manor Iii scores 76 out of 100 on ENERGY STAR — band B, above median (70–84) — in its 2024 California disclosure. Scores are national percentiles against similar buildings; 75+ qualifies for ENERGY STAR certification.
How much energy does Windsor Manor Iii use?
Its 2024 site energy-use intensity was 35.2 kBtu/ft² across 52,000 sq ft, including 203,146 kWh of electricity and 12,201 therms of natural gas.
What are Windsor Manor Iii's carbon emissions?
Windsor Manor Iii reported 111 tCO₂e of greenhouse-gas emissions (2.1 kgCO₂e/ft²) for 2024.
Where is Windsor Manor Iii?
Windsor Manor Iii is at 535 Autumn Drive, San Marcos, in San Marcos, California 92069. Its coordinates are 33.14413, -117.17334 (latitude, longitude), as published in the Building Energy Benchmarking Program (statewide) file.
How big is Windsor Manor Iii and when was it built?
Windsor Manor Iii has 52,000 sq ft of gross floor area, as reported in its 2024 disclosure. The disclosure lists 1984 as its year built. It is classed as multifamily housing.
Is Windsor Manor Iii 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, “Windsor Manor Iii, San Marcos, California — 2024 benchmarking disclosure”, https://buildingcensus.com/buildings/california/windsor-manor-iii-4e16ff09 (data as of July 9, 2026).