All 58 counties and all 16 climate zones. Documentation is produced remotely, so turnaround is identical wherever your project sits. Field verification is scheduled regionally.
Los Angeles County · Climate Zone 6 and 9
Los Angeles projects span coastal Climate Zone 6 and inland Zone 9 within a single city boundary, and the zone assigned to your address changes the compliance margin materially.
Los Angeles Title 24 →San Diego County · Climate Zone 7
San Diego sits mostly in Climate Zone 7, one of California's mildest, which often makes the performance path unusually favourable — but the city's own reach codes and all-electric provisions have to be layered on top of the state standards..
San Diego Title 24 →Santa Clara County · Climate Zone 4
Santa Clara County projects sit in Climate Zone 4 with some of the state's most aggressive local reach codes.
San Jose Title 24 →San Francisco County · Climate Zone 3
San Francisco's Climate Zone 3 is heating-dominated and cooling-light, which shapes every trade-off in the model.
San Francisco Title 24 →Fresno County · Climate Zone 13
Central Valley Climate Zone 13 is cooling-dominated and unforgiving.
Fresno Title 24 →Sacramento County · Climate Zone 12
Climate Zone 12 covers most of the Sacramento region — hot dry summers with genuinely cold winter mornings, so the model has to satisfy both ends rather than optimising for one..
Sacramento Title 24 →Los Angeles County · Climate Zone 6
Coastal Climate Zone 6 with mild loads, plus a city plan-check process with its own documentation habits and a very high volume of multifamily and mixed-use work..
Long Beach Title 24 →Alameda County · Climate Zone 3
Alameda County projects sit in Climate Zone 3 with several jurisdictions enforcing all-electric reach codes.
Oakland Title 24 →Kern County · Climate Zone 13
Kern County's Climate Zone 13 conditions put sustained pressure on cooling capacity and duct performance.
Bakersfield Title 24 →Orange County · Climate Zone 8
Orange County's Climate Zone 8 is a moderate inland profile.
Anaheim Title 24 →Riverside County · Climate Zone 10
Inland Empire Climate Zone 10 carries substantial cooling load with meaningful winter heating.
Riverside Title 24 →San Bernardino County · Climate Zone 10
Climate Zone 10 with significant logistics and industrial development alongside residential growth.
San Bernardino Title 24 →San Joaquin County · Climate Zone 12
San Joaquin County sits in Climate Zone 12 with Valley heat and Delta influence.
Stockton Title 24 →Orange County · Climate Zone 8
Master-planned development at scale in Climate Zone 8, with sophisticated design teams and correspondingly high documentation standards from the city..
Irvine Title 24 →Stanislaus County · Climate Zone 12
Stanislaus County projects fall in Climate Zone 12.
Modesto Title 24 →Ventura County · Climate Zone 6
Coastal Ventura County sits in Climate Zone 6 with mild loads and a heavy agricultural and cold-storage nonresidential base — refrigerated warehouse work has its own compliance profile entirely..
Oxnard Title 24 →Los Angeles County · Climate Zone 9
Climate Zone 9 with a municipal utility of its own, which changes both the incentive landscape and some of the coordination around electrification projects..
Glendale Title 24 →Los Angeles County · Climate Zone 9
Climate Zone 9 with a municipal utility and a substantial historic building stock, where envelope upgrades have to be reconciled with preservation constraints..
Pasadena Title 24 →Sonoma County · Climate Zone 2
Sonoma County sits in Climate Zone 2, which is heating-dominated with cool nights.
Santa Rosa Title 24 →Riverside County · Climate Zone 15
Climate Zone 15 is the state's most cooling-dominated, and compliance here is genuinely difficult.
Palm Springs Title 24 →Riverside County · Climate Zone 10
Climate Zone 10 with steady production-housing volume and a growing commercial base.
Temecula Title 24 →Sacramento County · Climate Zone 12
Climate Zone 12 with sustained subdivision development.
Elk Grove Title 24 →San Diego County · Climate Zone 7
Climate Zone 7 with a city that has been unusually active on reach codes and electrification.
Chula Vista Title 24 →Los Angeles County · Climate Zone 9
Climate Zone 9 with substantial master-planned residential development and a growing commercial and studio-facility base..
Santa Clarita Title 24 →California is divided into 16 building climate zones for the purposes of Title 24, and they are assigned by ZIP code. This is the detail that most often produces a rejected report, because city and county boundaries do not follow zone boundaries. Los Angeles spans several. So does San Diego County.
Zone assignment determines every prescriptive requirement and every performance trade-off available to your design, so we confirm it from the project address at intake rather than inferring it from the city name.
Mild, heating-dominated or nearly load-neutral. Compliance margins are usually comfortable, and the performance path often opens up design freedom.
Genuine heating and cooling demand in the same building. The model has to satisfy both ends rather than optimising for one.
The hardest zones in the state. Envelope, glazing and equipment efficiency all have to work substantially harder to reach compliance.
Not sure which zone your project is in? Send the address — we confirm it at intake as a matter of routine, at no charge, before any work is quoted.
Same-day reports available. Send the plans, tell us the deadline, and we will work to it.