Do I need a permit for an accessory dwelling unit (ADU) in
Hemet, California?

Hemet ADU permits — the key details

California Government Code 65852.2 (the primary state ADU law) mandates that Hemet approve ADUs on single-family residential lots if the project meets objective standards — lot size, setbacks, height, parking (which Hemet cannot require for detached ADUs per AB 881), and building code compliance. The city cannot impose design review, public hearings, conditional use permits, or discretionary approval for ADUs that meet these objective criteria. Hemet's local interpretation of these standards appears in the city's ADU checklist and the Riverside County Building Code amendments. A key threshold: ADUs up to 1,200 square feet (or 65% of the primary dwelling, whichever is smaller) are streamlined; anything larger triggers full plan review. Junior ADUs (a room within the primary house with separate entrance, sink, cooktop, and refrigerator) are exempt from parking, owner-occupancy, and lot-size requirements under Government Code 65852.22, but still require a permit and must meet egress and utility standards.

Setbacks in Hemet apply per the local zoning ordinance as informed by state law: typically, detached ADUs must be set back 5 feet from rear and side lot lines (verify your specific zone), and cannot exceed 35 feet in height. The city's online ADU checklist (available on the Hemet ePermit portal) lists exact setback distances by zone, which saves time — print it and compare your site plan before filing. If your lot is irregular, a title/site survey is strongly recommended ($300–$600) to avoid a rejection for setback encroachment. For garage conversions, the setback rules remain the same, but the city requires that you show (on the plans) that the conversion does not reduce parking below the primary dwelling's requirement (typically 2 spaces); if the primary home already has 2 off-street spaces elsewhere, the garage conversion poses no parking issue. Owner-occupancy of the primary dwelling is required under state law (AB 881 removed some local owner-occupancy mandates, but Hemet's current interpretation still expects the owner to occupy one of the two units — verify this with the city before filing, as state law continues to evolve).

Utility connections and egress are the two most common rejection triggers in Hemet ADU applications. The city requires separate water and sewer connections (or sub-metering) shown on the utility plans — you cannot share a single water meter or sewer lateral with the primary house. If your lot's utility infrastructure cannot support a separate connection (rare, but possible on small lots in older neighborhoods), the city will request engineering analysis or a variance. Egress windows must comply with IRC R310.1: minimum 5.7 square feet of openable area, at least 20 inches wide and 37 inches tall, sill height no more than 44 inches above the floor, and openable from the inside without a key. For bedrooms (required if the ADU is marketed as a 1-bedroom or larger), you need at least one compliant egress window; if you have only one bedroom in a detached ADU, that window must serve as both the primary exit and the emergency egress. Plan reviewers in Hemet routinely request revised elevations and room schedules if window details are vague.

Hemet's permit fee for a new detached ADU typically ranges from $5,000 to $12,000, depending on square footage and complexity. This includes plan review ($800–$1,500), building permit ($2,500–$6,000 based on valuation), mechanical/electrical/plumbing permit add-ons ($800–$1,200), and planning/zoning clearance ($500–$1,000). The city calculates building permit fees as a percentage of the estimated construction cost (typically 0.76% of valuation for residential) plus a base fee. For a 600-square-foot detached ADU with an estimated construction cost of $120,000, expect a building permit in the $2,200–$3,000 range, plus about $1,500 in MEP and plan-review fees. Garage conversions cost less (roughly 40-50% of detached ADU fees) because they involve no foundation work and minimal structural review. The city's ePermit portal shows a fee estimate during application, so you can lock in the cost before committing.

Timeline: Hemet processes ADU permits under California's 60-day shot-clock rule (AB 671). A complete application receives a first response — approval, conditional approval, or request for more information — within 60 days. If the city requests corrections (e.g., revised setback calculations, egress details, utility plans), you have 30 days to respond, which restarts a new 60-day clock. A straightforward detached ADU on a clear lot takes 8-10 weeks from submittal to permit issuance; a garage conversion in good order can close in 6-8 weeks. Once the permit is issued, you typically have 180 days to pull electrical, mechanical, and plumbing sub-permits before they expire. Construction inspection sequence: foundation (if detached), framing, rough trades (MEP rough-in), insulation, drywall, final building inspection, and utility sign-off (water/sewer/electric). Total construction time for a small detached ADU is 12-16 weeks; a garage conversion is 6-10 weeks.

Three Hemet accessory dwelling unit (adu) scenarios

California ADU State Law vs. Hemet Local Code — What You Actually Control and What You Don't

California Government Code 65852.2 (primary ADU law, updated by AB 881, SB 9, and AB 671) sets a floor, not a ceiling, for what Hemet can require. The state says: ADUs are allowed on single-family lots, owner must occupy one unit, lot must be at least 0.5 acres for a detached ADU (state minimum — local can be stricter, but Hemet does not enforce a stricter minimum in most zones), and the city cannot require parking unless it requires parking for the primary dwelling in that zone. Hemet's local code cannot block ADUs outright or impose discretionary approval (design review, public hearings, conditional use permits) if the project meets objective standards (setback, height, building code). The city's job is to process, not to approve or disapprove at will.

What Hemet can enforce: setbacks (5 feet rear/side in most R1 zones), maximum height (typically 35 feet measured from grade), lot-line distances, egress windows (IRC R310.1), separate utility connections or sub-metering (this is local, not state mandated, but Hemet enforces it as a condition of occupancy), and flood-zone compliance if applicable (Hemet has limited FEMA flood zones, but the western foothills near San Bernardino National Forest are in State Responsibility Areas for fire-zone setbacks — check your specific address). What Hemet cannot enforce: design review, parking for detached ADUs or junior ADUs (AB 881), reduced lot size for junior ADUs, or conditional approval based on neighborhood character.

The 60-day shot clock (AB 671) is a hard deadline. If Hemet issues no response within 60 calendar days of a complete application, the application is deemed approved. This is rare in practice (most cities respond within 30-45 days to request corrections), but it is a backstop. If you submit a marginal application and the city misses the 60-day window, you can force approval. Many applicants track the calendar and escalate to the planning manager on day 55 if they hear nothing. Hemet's ePermit portal shows application status and the 60-day clock countdown, reducing ambiguity.

Utility Separation, Sub-Metering, and Why Hemet Enforces It Strictly

California ADU law does not explicitly require separate utility connections; it requires only that utilities be adequate and compliant with code. However, Hemet has interpreted this to mean: detached ADUs must have their own water meter (or sub-meter) and sewer connection, shown on utility plans and signed off by the city's water and sewer departments. Garage conversions attached to the primary home typically share utilities (they are an extension of the primary dwelling), but the city prefers sub-metering even for attached units to track ADU water use separately — this is a city-level policy, not state law. The city's reason: water and sewer bills, property tax assessment for ADU-occupied units, and future resale disclosure (buyers want to know which utilities are shared). Most sub-meters cost $800–$1,500 installed (materials + labor); sewer laterals, if not already stubbed to the rear, add $1,500–$3,000.

If your lot's existing infrastructure cannot support a separate sewer connection (e.g., the main lateral is at the street and a secondary lateral to the rear would require boring under a large tree or rock outcrop), the city will request a waiver or variance from the separate-sewer requirement. Hemet is not flexible on this — expect a lengthy conditional-approval letter and a request for an engineer's report justifying why separate sewer is infeasible. Some applicants take the variance route; approval is not guaranteed and adds 4-8 weeks. A practical alternative: if the sewer is a genuine hardship, propose a sub-metered shared-sewer arrangement (ADU drains to primary home's lateral but has its own meter at the property-line boundary). This is a compromise the city sometimes accepts, but verify before filing.

Water sub-meters are almost always required in Hemet and are straightforward to install. The plumber runs a secondary line from the main water service to a meter pit near the ADU, then feeds the ADU. Cost is typically $900–$1,500 all-in. Electric sub-metering is less common (the ADU usually has its own circuit breaker panel fed from the primary home's main panel or a separate service), but if you share a single electric meter, the utility company will require sub-metering or a separate service installation ($2,000–$4,000). Ask your local utility (Hemet is served by Southern California Edison and local water agencies) what their ADU sub-metering policy is before you finalize plans.

Common questions