Who issues ADU permits in Placer County?

It depends on your city. Roseville permits through the City of Roseville Development Services; Rocklin permits through the City of Rocklin Community Development Department; Lincoln permits through the City of Lincoln Building Division; Loomis permits through the Town of Loomis / Placer County Building Division; Auburn permits through the City of Auburn / Placer County Building Division; Granite Bay permits through the Placer County Community Development Resource Agency. We prepare the package and manage every inspection for whichever office governs your lot.

What are the ADU setback and size rules in Placer County?

Placer County follows California's statewide ADU standards: a 4 ft side and rear setback (cities can't require more), detached units up to 1,200 sq ft, a 16 ft height limit (taller near major transit), and no replacement parking for garage conversions. Units under 750 sq ft are exempt from impact fees.

Do Placer County ADUs have an owner-occupancy requirement?

Standard ADUs permitted on or after January 1, 2020 have no owner-occupancy requirement — you can rent both the main house and the ADU. Junior ADUs are the exception and still require the owner to live in the main house or the JADU.

Placer County · Rules & Permits

Placer County ADU Rules, Setbacks & Permits

Name: Upside ADU
Address: Sacramento, CA, US
Telephone: (916) 282-5283
Price range: $$$

Updated June 12, 2026 · Upside ADU

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Quick answer

Placer County ADUs follow California's statewide rules: a 4 ft side/rear setback, detached units up to 1,200 sq ft, a 16 ft height limit, no added parking, and a 60-day permit clock. Placer County ADUs are permitted by individual city counters (Roseville, Rocklin, Lincoln) or, in unincorporated areas like Granite Bay, by the county directly. The biggest local variable is HOA architectural review in master-planned tracts, plus foothill site conditions in Auburn and Loomis.

Who permits your ADU in Placer County?

Placer County spans several jurisdictions, and the office that reviews your ADU depends on your address. We handle the submittal and inspections for whichever one applies.

Placer County ADU permitting authority by city

City	Permitting authority	ADU pages
Roseville	City of Roseville Development Services	builder · cost
Rocklin	City of Rocklin Community Development Department	builder · cost
Lincoln	City of Lincoln Building Division	builder · cost
Loomis	Town of Loomis / Placer County Building Division	builder · cost
Auburn	City of Auburn / Placer County Building Division	builder · cost
Granite Bay	Placer County Community Development Resource Agency	builder · cost

What are the ADU size, setback, and height limits?

These are set by California state law and apply across Placer County — a city cannot make them more restrictive:

Detached ADU: up to 1,200 sq ft
Side & rear setback: 4 ft minimum (state floor)
Height: 16 ft, or up to 25 ft within ½ mile of major transit
Parking: none required for a garage conversion
Impact fees: waived for units under 750 sq ft
Owner-occupancy: none for standard ADUs permitted after Jan 1, 2020 (JADUs excepted)

What's different about building in Placer County?

Expect HOA design review in Fiddyment Farm, Whitney Ranch, Stanford Ranch, Sun City, and Los Lagos. Foothill and rural-residential parcels (Auburn, Loomis, parts of Granite Bay) commonly involve septic capacity, well, slope, and fire-zone (WUI) requirements that get scoped before a bid.

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Orientation only, not a permit determination — Placer County jurisdictions update ordinances as state law changes. We confirm the current rules for your specific lot during a free feasibility check.

Sources & references

Accessory Dwelling Units — official guidance — California Dept. of Housing & Community Development (HCD)
California ADU law (SB 1211, AB 1033) — California Legislative Information

Placer County ADU rules — FAQs

: It depends on your city. Roseville permits through the City of Roseville Development Services; Rocklin permits through the City of Rocklin Community Development Department; Lincoln permits through the City of Lincoln Building Division; Loomis permits through the Town of Loomis / Placer County Building Division; Auburn permits through the City of Auburn / Placer County Building Division; Granite Bay permits through the Placer County Community Development Resource Agency. We prepare the package and manage every inspection for whichever office governs your lot.
: Placer County follows California's statewide ADU standards: a 4 ft side and rear setback (cities can't require more), detached units up to 1,200 sq ft, a 16 ft height limit (taller near major transit), and no replacement parking for garage conversions. Units under 750 sq ft are exempt from impact fees.
: California law requires a decision on a complete application within 60 days. Pre-approved plan sets can shorten plan check to roughly 30 days. Expect HOA design review in Fiddyment Farm, Whitney Ranch, Stanford Ranch, Sun City, and Los Lagos. Foothill and rural-residential parcels (Auburn, Loomis, parts of Granite Bay) commonly involve septic capacity, well, slope, and fire-zone (WUI) requirements that get scoped before a bid.
: Standard ADUs permitted on or after January 1, 2020 have no owner-occupancy requirement — you can rent both the main house and the ADU. Junior ADUs are the exception and still require the owner to live in the main house or the JADU.

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