Title 24 Reports in Placer County

Elevation does all the work

Placer County is a long east–west strip that starts near the Sacramento Valley floor and ends at the Nevada state line above Lake Tahoe. Zone 11 covers the western, lower end — Roseville, Rocklin, Lincoln, Loomis, Auburn and the foothill communities. Zone 16 covers the mountains and the Tahoe basin.

Eighteen of the thirty ZIP codes we derive for the county are zone 11 and twelve are zone 16, which is a more even division than most multi-zone counties manage — the county genuinely has two substantial halves rather than a dominant zone and an outlier.

What each half demands

Zone 11 is a hot-summer valley and foothill climate where cooling drives the calculation. Zone 16 is the coldest assignment in the state, where heating, envelope performance and snow loading dominate. A design that performs well in Roseville is solving a different problem from one at Tahoe.

A zone we did not claim

Being straight about the data: a third zone, 12, appears in the county only through ZIP codes that sit mostly in neighbouring Sacramento County, along the shared boundary. Because Placer does not hold the larger share of those, we do not list zone 12 as a Placer County zone. If your project is close to that county line, the ZIP check matters more than usual.

Example ZIP codes and their zones

Derived from the Energy Commission's ZIP-to-climate-zone table, with county membership taken from the U.S. Census Bureau's 2020 ZCTA-to-county relationship file:

• Climate zone 11 — 95603, 95648, 95661, 95678, 95747 and 13 more
• Climate zone 16 — 95701, 95717, 96140, 96143, 96145 and 7 more

ZIP codes that cross the county line

A ZIP code is a postal boundary, not a county boundary, and several here fall on both sides of one. Where that happens we do not treat the county as settling the question:

• 95728 — about 77% within Placer County, the remainder in Nevada 23%
• 95602 — about 79% within Placer County, the remainder in Nevada 21%

For an address in one of these, the climate zone still comes from the ZIP code, which is assigned by the Energy Commission regardless of the county line. What the split affects is which jurisdiction issues the permit — worth confirming before a submittal.

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 Placer 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.

City and unincorporated permitting

A project inside a city's limits is permitted by that city. A project on unincorporated land is permitted by the county instead, and the two can run different submittal processes even where the energy requirements are identical. The California Energy Code is statewide — what changes locally is the climate zone the site falls in and how the jurisdiction wants the compliance documents presented.

Climate zones in Placer County

Placer County contains California climate zones 11 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.