Valley Floor, Foothills and Ridge Lines
The biggest difference between a window job in one of our communities and the next is elevation, because it decides the energy zone and the fire question before style comes up. Most of the valley floor, San Bernardino included, sits in Title 24 Climate Zone 10, the hot inland zone on the California Energy Commission's ZIP list. Two San Bernardino ZIP codes, 92402 and 92404, fall in Climate Zone 16, the mountain zone, and Claremont's 91711 is Climate Zone 9. The zone comes from the address, not the county, so we look it up for every quote.
Up against the San Gabriel and San Bernardino mountains, the conversation turns to wildfire. California's Wildland-Urban Interface Code, Part 7 of Title 24, carries the rules once found in Chapter 7A of the Building Code, and in a mapped Very High Fire Hazard Severity Zone replacement windows in an alteration are generally expected to comply. Zones are set parcel by parcel, so no city page here claims a whole community is in or out.
- Valley floor: heat gain, Solar Heat Gain Coefficient and frames that hold up in the sun
- Foothills: tempered glass, ignition-resistant frames and wind
- Ridge lines: big view openings, wind load and the same fire check
San Antonio Heights sits at 2,103 feet against the San Gabriels, Woodcrest rises above 2,000 feet in places, and El Sobrante's hills look over Lake Mathews, so the foothill rules reach well beyond the mountain towns.