Title 24 Reports in Calaveras County

Up Highway 4

Sixteen of the county's eighteen ZIP codes are zone 12. The two zone 16 ZIP codes, 95224 and 95233, sit on the Highway 4 corridor north-east of Murphys, and Avery straddles both. Below that point the highway is zone 12 throughout: Angels Camp, Vallecito, Murphys and Forest Meadows all have zone 12 ZIP codes.

Arnold is counted with Alpine

Arnold is a Calaveras County community, and its ZIP code, 95223, is zone 16. But on the Census relationship file only about 17 per cent of that ZIP's land lies in Calaveras; 81 per cent is in Alpine County, because the ZIP runs east over the county line into the high country. A ZIP belongs to whichever county holds its largest share, so 95223 is not on the Calaveras list.

For an Arnold project the result is the same either way — the zone comes from the ZIP, and 95223 is zone 16 wherever it is filed. Dorrington, higher up the highway, shares it. This is the kind of quirk land-area shares produce, which is why we state the method rather than smooth it over.

A foothill county with one high corner

Most of Calaveras is zone 12 foothill country. Valley Springs and Copperopolis sit low in the west and south; San Andreas and Mokelumne Hill in the middle. Mountain Ranch and West Point, higher up to the north-east, are still zone 12. Angels Camp, which the California Department of Finance's 2026 estimates list as Angels City, is the county's only incorporated city and is zone 12 too. Only a site inside its limits has a city permit; the rest of Calaveras, 95224 and 95233 included, is unincorporated county land.

Hot summers make cooling the heavier load across the zone 12 side. In 95224 and 95233 the calculation turns round: retaining heat matters more than rejecting it, so the envelope and the heating system carry the result.

Every ZIP code by zone

Zones per the Energy Commission; county membership and community names per the 2020 Census.

• Climate zone 12 — 95221; 95222 (Angels); 95225; 95226; 95228 (Copperopolis); 95232; 95245 (Rail Road Flat, Mokelumne Hill); 95246 (Mountain Ranch); 95247 (Murphys, Forest Meadows); 95248 (Rail Road Flat); 95249 (San Andreas); 95251 (Vallecito); 95252 (Rancho Calaveras, Valley Springs); 95254 (Wallace); 95255 (West Point); 95257
• Climate zone 16 — 95224 (Avery); 95233 (Avery)

No ZIP code here is split

All eighteen lie wholly inside Calaveras by Census land area. The high-country ZIP that does cross a county line, Arnold's 95223, belongs mostly to Alpine County and is explained above.

Finding the zone for your own project

The zone is set by the project's location and confirmed from the ZIP code against the Energy Commission's published table — not from the county name and not from the nearest large town. Because Calaveras County contains more than one zone, that check decides which set of numbers a report is written against.

Give us the project address and we determine the zone as part of preparing the report. It is the first thing established, because every insulation, glazing and equipment figure downstream depends on it.

Climate zones in Calaveras County

Calaveras County contains California climate zones 12 and 16. The zone drives the insulation, glazing and equipment performance a report has to demonstrate, and it is confirmed from the project ZIP code against the Energy Commission's published table.