Ayres Suites Ontario Mills
Hotel in California, CA · 4370 Mills Circle, Ontario · 91764
At a glance
Ayres Suites Ontario Mills is a 85,422-square-foot hotel at 4370 Mills Circle, Ontario in Ontario, California, built in 1998. In its 2024 California benchmarking disclosure it reported an ENERGY STAR score of 97 out of 100 (grade A), a site energy-use intensity of 52.4 kBtu/ft² and 265 tCO₂e of greenhouse-gas emissions. That score is higher than 82% of the 1,525 scored hotel buildings in California.
AB 802 (Public Resources Code §25402.10) · reporting year 2024
Benchmarking record
| Field | Value |
|---|---|
| ENERGY STAR score | 97 (band A) |
| Site EUI | 52.4 kBtu/ft² |
| Source EUI | — |
| GHG emissions | 265 tCO₂e |
| GHG intensity | 3.1 kgCO₂e/ft² |
| Electricity | 605,603 kWh |
| Natural gas | 24,013 therms |
| Gross floor area | 85,422 sq ft |
| Source record | california:6844983:2024 |
The disclosure history
Year over year
| Year | Score | Δ | Site EUI | GHG emissions |
|---|---|---|---|---|
| 2024latest | 97 | -2 | 52.4 kBtu/ft² | 265 tCO₂e |
| 2023 | 99 | — | 222 tCO₂e | |
| 2022 | — | — | — | |
| 2020 | 98 | +4 | 47.7 kBtu/ft² | 228 tCO₂e |
| 2019 | 94 | +1 | 55.7 kBtu/ft² | 292 tCO₂e |
| 2018 | 93 | 57.1 kBtu/ft² | 302 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
- 4370 Mills Circle, Ontario
- City
- California
- State
- California
- ZIP
- 91764
- Coordinates
- 34.07047, -117.55738
Within ~1 km
Nearby benchmarked buildings
- Ontario Millsscore —
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- 5218-Ontario Millsscore —
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- Reserve At Empire Lakes - 29121score 95
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- Mathis Home - Ontarioscore 99
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Strip Mall · 225,749 sq ft
See also: most efficient in California · biggest emitters
How does Ayres Suites Ontario Mills compare with other hotel buildings in California?
The latest disclosures cover 1,599 hotel buildings in California, out of 40,029 buildings citywide. Ayres Suites Ontario Mills's ENERGY STAR score of 97 compares with an average of 74 across the 1,525 that report a score; it scores higher than 82% of them and lower than 15%. Its site EUI of 52.4 kBtu/ft² is about 20% below the average of 65.6 kBtu/ft² — it uses less energy per square foot than the typical building in that group. Its emissions intensity of 3.1 kgCO₂e/ft² is about 22% below the group average of 4.0 kgCO₂e/ft².
At 85,422 sq ft, it is about half of the average floor area of 167,786 sq ft for those buildings. It was built in 1998, 10 years later than the group's average year built (1988). Across all 24 jurisdictions BuildingCensus covers, the 3,812 hotel buildings average an ENERGY STAR score of 65 and a site EUI of 77.8 kBtu/ft².
How has Ayres Suites Ontario Mills's energy performance changed over time?
BuildingCensus holds 6 California disclosures for Ayres Suites Ontario Mills, covering report years 2018, 2019, 2020, 2022, 2023, 2024. Its ENERGY STAR score went from 93 in 2018 to 97 in 2024 (+4 points); its best year on file was 2023, at 99. Site EUI moved from 57.1 kBtu/ft² (2018) to 52.4 kBtu/ft² (2024), a 8% decrease. Reported emissions went from 302 tCO₂e to 265 tCO₂e over the same span (down 12%).
What does an ENERGY STAR score of 97 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 97 means the building performs better than about 97% of its national peers. BuildingCensus bands the score into report-card grades; 97 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. Ayres Suites Ontario Mills's 52.4 kBtu/ft² across 85,422 sq ft works out to about 4.5 billion Btu (1,312 MWh-equivalent) in 2024. The disclosure also reports 605,603 kWh of electricity and 24,013 therms of natural gas for the year.
Which law requires Ayres Suites Ontario Mills to report its energy use?
Ayres Suites Ontario Mills 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:6844983:2024). 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 hotel buildings in California
- Hilton Garden Inn San Francisco Airport North· 85,000 sq ft · EUI 23.2 kBtu/ft²
- 149, Hilton Garden Inn - San Francisco Airport· 85,000 sq ft
- 311L5 - Sorrento Mesa/La Jolla Courtyard· 85,000 sq ft · score 99 (A)
- 585Yd-Fairfield Inn Santa Ana Tustin· 84,551 sq ft · score 87 (A)
- 311L8-Laxhh-Hacienda Heights Courtyard· 84,516 sq ft · score 87 (A)
- Aloft Cupertino· 84,410 sq ft · EUI 50.6 kBtu/ft²
- Hotel buildings in California· 1,599 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 Ayres Suites Ontario Mills's energy grade?
Ayres Suites Ontario Mills scores 97 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 Ayres Suites Ontario Mills use?
Its 2024 site energy-use intensity was 52.4 kBtu/ft² across 85,422 sq ft, including 605,603 kWh of electricity and 24,013 therms of natural gas.
What are Ayres Suites Ontario Mills's carbon emissions?
Ayres Suites Ontario Mills reported 265 tCO₂e of greenhouse-gas emissions (3.1 kgCO₂e/ft²) for 2024.
Where is Ayres Suites Ontario Mills?
Ayres Suites Ontario Mills is at 4370 Mills Circle, Ontario, in Ontario, California 91764. Its coordinates are 34.07047, -117.55738 (latitude, longitude), as published in the Building Energy Benchmarking Program (statewide) file.
How big is Ayres Suites Ontario Mills and when was it built?
Ayres Suites Ontario Mills has 85,422 sq ft of gross floor area, as reported in its 2024 disclosure. The disclosure lists 1998 as its year built. It is classed as hotel.
Is Ayres Suites Ontario Mills 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, “Ayres Suites Ontario Mills, Ontario, California — 2024 benchmarking disclosure”, https://buildingcensus.com/buildings/california/ayres-suites-ontario-mills-9505ec17 (data as of July 9, 2026).