Title 24 reports in Ontario.
CF1R and NRCC energy compliance for Ontario projects: new homes, ADUs, additions, remodels and commercial work. From $200, back in two business days, with plan-check corrections included.
Ontario is in Climate Zone 10, Inland Empire and Inland San Diego
Hot summers and real winter nights. High volume, and cooling loads big enough that design choices show up in the results.
Where Ontario projects usually lose margin: This is where projects fail on glazing. Keep west-facing window area honest and specify low SHGC.
Every compliance run for a Ontario project uses the CEC weather file for Riverside, the reference station for Zone 10. That file, not the address, is what the energy budget is calculated against, which is why getting the zone right matters more than anything else about location.
Read Zone 10 in full →ADUs and conversions
From $200. Most are exempt from the solar PV requirement; envelope and equipment rules still apply in full.
Additions and remodels
From $300. Modelled as two zones, existing and addition, so the new floor area is judged on its own standard.
New homes
From $300, including solar PV and battery sizing to the 2025 code.
Commercial & TI
Quoted on a call. NRCC envelope, mechanical and lighting plus the performance run.
Ontario climate zone lookup
Pre-set to Zone 10. Enter any other Ontario-area ZIP to check a specific address.
Schematic: nodes are placed for legibility, not survey accuracy. Zone boundaries follow ZIP code lines.
Enter a city or ZIP code, or click any numbered node on the map, and we'll tell you the zone, what drives the design there, and where projects usually lose margin.
Zone assignment is set by the California Energy Commission and follows ZIP code boundaries. A handful of cities straddle two zones. If yours is one of them we will confirm it from the address for free.
Title 24 in Ontario
How much does a Title 24 report cost in Ontario?
The same published rates as everywhere else in California: from $200 for an ADU or garage conversion, and $300 for an addition or remodel. Commercial NRCC work and multifamily are quoted on a call. Ontario projects are not priced differently. The calculator on this site gives you the exact number.
Which climate zone is Ontario in?
Ontario sits in California Climate Zone 10, Inland Empire and Inland San Diego. The compliance model runs against the CEC weather file for Riverside, and design is driven mainly by cooling.
Zone assignment follows ZIP code boundaries, so a large city can span more than one zone. Send us the project address and we'll confirm it free.
Do you work with Ontario building departments?
Yes. Reports are produced to the state standard, which is what every California jurisdiction plan-checks against, and the forms sheet is sized to drop straight into your plan set. If Ontario plan check comes back with a comment on the energy documents, the correction is included at no charge.
Also serving
All 58 California counties and all 16 climate zones. See the full list.
Have a Ontario project? Send the plans.
Fixed price and a delivery date the same day, then signed forms in five business days.
Or call (909) 914-0305 and you'll get the engineer, not a receptionist.