Royal Iolani AOAO
Multifamily Housing in Honolulu, HI · 581 Kamoku St, Honolulu
At a glance
Royal Iolani AOAO is a 441,000-square-foot multifamily housing building at 581 Kamoku St, Honolulu in Honolulu, Hawaii, built in 1978. In its 2025 Honolulu benchmarking disclosure it reported a site energy-use intensity of 28.5 kBtu/ft² and 2,502 tCO₂e of greenhouse-gas emissions.
Ordinance 22-17 (City & County of Honolulu) · reporting year 2025
Benchmarking record
| Field | Value |
|---|---|
| ENERGY STAR score | — |
| Site EUI | 28.5 kBtu/ft² |
| Source EUI | — |
| GHG emissions | 2,502 tCO₂e |
| GHG intensity | — |
| Electricity | 3,679,390 kWh |
| Natural gas | 172 therms |
| Water use | 18,194 kgal |
| Gross floor area | 441,000 sq ft |
| Source record | honolulu:04QFJ2201554261:2025 |
The disclosure history
Year over year
| Year | Score | Δ | Site EUI | GHG emissions |
|---|---|---|---|---|
| 2025latest | — | 28.5 kBtu/ft² | 2,502 tCO₂e | |
| 2024 | 94 | -6 | 29.0 kBtu/ft² | 2,695 tCO₂e |
| 2023 | 100 | 19.9 kBtu/ft² | 1,915 tCO₂e |
Compliance context
Ordinance 22-17 (City & County of Honolulu)
Honolulu's Ordinance 22-17 requires commercial buildings over 25,000 sq ft on Oʻahu to benchmark annually, with public disclosure of results.
Ownership
No owning organisation shown. Names of private individuals in the disclosure are not published here.
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Location
- Address
- 581 Kamoku St, Honolulu
- City
- Honolulu
- State
- Hawaii
Within ~1 km
Nearby benchmarked buildings
This source publishes no coordinates, so nearby buildings can't be resolved yet.
See also: most efficient in Honolulu · biggest emitters
How does Royal Iolani AOAO compare with other multifamily housing buildings in Honolulu?
The latest disclosures cover 378 multifamily housing buildings in Honolulu, out of 799 buildings citywide. Its site EUI of 28.5 kBtu/ft² is roughly in line with the average of 28.2 kBtu/ft².
At 441,000 sq ft, it is about 177% above the average floor area of 159,294 sq ft for those buildings. Its 1978 construction date is close to the group's average year built (1979). 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 Royal Iolani AOAO's energy performance changed over time?
BuildingCensus holds 3 Honolulu disclosures for Royal Iolani AOAO, covering report years 2023–2025. Its ENERGY STAR score went from 100 in 2023 to 94 in 2024 (-6 points); its best year on file was 2023, at 100. Site EUI moved from 19.9 kBtu/ft² (2023) to 28.5 kBtu/ft² (2025), an 43% increase. Reported emissions went from 1,915 tCO₂e to 2,502 tCO₂e over the same span (up 31%).
What does a site EUI of 28.5 kBtu/ft² mean?
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. Royal Iolani AOAO's 28.5 kBtu/ft² across 441,000 sq ft works out to about 12.6 billion Btu (3,683 MWh-equivalent) in 2025. The disclosure also reports 3,679,390 kWh of electricity, 172 therms of natural gas and 18,194 thousand gallons of water for the year.
Which law requires Royal Iolani AOAO to report its energy use?
Royal Iolani AOAO reports under Ordinance 22-17 (City & County of Honolulu), the legal basis of Honolulu's Better Buildings Benchmarking program, which publishes each covered building's annual benchmarking results. The record shown here is the report-year 2025 disclosure (source record honolulu:04QFJ2201554261:2025). Honolulu's Ordinance 22-17 requires commercial buildings over 25,000 sq ft on Oʻahu to benchmark annually, with public disclosure of results.
More multifamily housing buildings in Honolulu
- Pacifica Honolulu· 430,200 sq ft · EUI 50.8 kBtu/ft²
- Allure Waikiki· 419,710 sq ft · EUI 29.6 kBtu/ft²
- The Colony At Hawaii Kai Peninsula· 406,042 sq ft · EUI 20.7 kBtu/ft²
- Capitol Place· 405,626 sq ft · EUI 39.5 kBtu/ft²
- Ala Wai Plaza· 397,381 sq ft · EUI 16.6 kBtu/ft²
- Three Regents· 396,284 sq ft
- Multifamily Housing buildings in Honolulu· 378 benchmarked
- All Honolulu benchmarked buildings· Ordinance 22-17 (City & County of Honolulu)
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Frequently asked questions
What is Royal Iolani AOAO's energy grade?
Royal Iolani AOAO did not report an ENERGY STAR score in its 2025 disclosure, but its site energy-use intensity was 28.5 kBtu/ft².
How much energy does Royal Iolani AOAO use?
Its 2025 site energy-use intensity was 28.5 kBtu/ft² across 441,000 sq ft, including 3,679,390 kWh of electricity and 172 therms of natural gas.
What are Royal Iolani AOAO's carbon emissions?
Royal Iolani AOAO reported 2,502 tCO₂e of greenhouse-gas emissions for 2025.
Where is Royal Iolani AOAO?
Royal Iolani AOAO is at 581 Kamoku St, Honolulu, in Honolulu, Hawaii.
How big is Royal Iolani AOAO and when was it built?
Royal Iolani AOAO has 441,000 sq ft of gross floor area, as reported in its 2025 disclosure. The disclosure lists 1978 as its year built. It is classed as multifamily housing.
Is Royal Iolani AOAO covered by Ordinance 22-17 (City & County of Honolulu)?
Yes — it appears in the 2025 Better Buildings Benchmarking disclosure, which lists the buildings reporting under Ordinance 22-17 (City & County of Honolulu).
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About this data
Source: Better Buildings Benchmarking (Ordinance 22-17 (City & County of Honolulu)), as published July 9, 2026. See the methodology for how records are matched, cleaned and scored.
Cite as: BuildingCensus, “Royal Iolani AOAO, Honolulu, Hawaii — 2025 benchmarking disclosure”, https://buildingcensus.com/buildings/honolulu/royal-iolani-aoao-23beb1db (data as of July 9, 2026).