How Much Does an ADU Cost in Sacramento, CA?

Construction Cost Breakdown

Building an ADU in Sacramento costs between $100,000-$250,000 for new construction, with per-square-foot costs averaging $150-$300. These figures include design, permitting, site preparation, and construction. The most affordable option is a garage conversion at $60,000-$140,000, while prefab/modular ADUs fall in between at $80,000-$200,000.

Permit Costs & Timeline

Permit fees in Sacramento are Replace the guessed range with the city's OWN published figures. Form CDD-0419, 'Accessory Dwelling Unit (ADU) Fee Estimate (New Construction)', revised 07-12-2026, at a $170.80/sq ft valuation: 749 sq ft = $5,271.90 total; 750 sq ft = $10,624.40; 1,200 sq ft = $14,842.50. Representative line items at 1,200 sq ft: building permit $1,790.36, building plan review $751.95, fire dept administrative $176, fire inspection $294 ($0.11/sq ft, $294 minimum), fire plan review $260, planning inspection $526, planning review $263, public works review $205 deposit + hourly, utilities $205 deposit + hourly, construction excise tax $945.60, general plan fee $533 ($2.60 per $1,000 valuation), residential construction tax $315, technology fee $254.23. NOT included and additional: school district impact fees (calculated and collected by the district, form CDD-0226), Regional Sanitation and Sewer Development fees (the form says 'Check with County'), and possible sewer/water tap, housing and project-area impact fees. The optional ADU Zoning Review is now $0 (the $117 fee was waived). An optional building permit fee estimate service costs $164 (form CDD-0278). Additional review time bills at $216/hr building, $263/hr planning. The city's own caveat: 'This is only an estimate. The actual fees can vary based on project scope, location, fee changes, etc.'. The review timeline is 60 days — correct, and this is genuinely in the CITY's code, not merely restated state law, which is worth saying. Two conditions our record omits: (1) the 60 days runs from a COMPLETE application and only where there is an existing residential use on the lot; (2) if the ADU is filed alongside an application for new residential development, the city may defer the ADU decision until the primary is approved, and the clock tolls for any applicant-requested delay. Deemed-approved remedy is in the code text. Separately, AB 1332 preapproved plans carry a 30-day approval — but see pre_approved_plans, the city's AB 1332 catalog is currently empty, so no homeowner can actually use that 30-day path today., with plan check: Standard review. Impact fees are Substantively correct — keep the state-law framing, but attach the city's actual dollar figures, which is where the value is. From CDD-0419: at 749 sq ft every impact fee line reads '-' (zero). At 750 sq ft they switch on: Park Development Impact Fee $2,617.50, SAFCA (Sacramento Area Flood Control Agency) Development Impact Fee $1,575.00, Sacramento Transportation Authority mitigation + 2% admin $1,154.64. At 1,200 sq ft: $4,188.00 / $2,520.00 / $1,415.76. Citywide Transportation Development Impact Fee shows as zero at all three sizes. School district impact fees apply at ANY size and are paid directly to the district. Net: crossing 750 sq ft adds roughly $5,347 in one step. The form flags that SAFCA/park/STA fees 'May be lower in certain infill areas or incentive zones'. IMPORTANT NEGATIVE FINDING: the City page titled 'reduction-of-development-impact-fees-for-new-adus' is NOT an ADU waiver — I read it, and it reduces certain impact fees to zero only for deed-restricted affordable dwelling units (30-year affordability, agency confirmation required, subject to funding availability). Do not write it up as an ADU incentive.. Pre-approved plans: True but it conflates two distinct programmes, and only one of them actually has plans in it today. (1) SHELF READY ADU PLANS — three free city-designed detached plan sets: studio 367, one-bedroom 559, two-bedroom 747 habitable sq ft. All-electric, meet 2022 Residential Building Code, also loaded into Symbium Build for site planning. Modifications are NOT allowed, though mirroring is; the applicant supplies a site plan. All three are deliberately under the 750 sq ft impact-fee threshold — a homeowner using the two-bedroom plan saves roughly $5,350 in impact fees versus a 750 sq ft custom unit. (2) AB 1332 PREAPPROVED ADU PROGRAM (Gov. Code 65852.27) — the city has stood up the required process and web page for third-party preapproved plans, but the catalog is CURRENTLY EMPTY: the page says 'Check back for regular updates' with no plans listed. Either route still requires site-specific planning and zoning approval before permit issuance. Recommend our page distinguishes the two and states the shelf-ready sizes, since that is the concrete saving..

Rental Income & ROI

A typical ADU in Sacramento generates approximately $18,600 per year in rental income based on average 1-bedroom rents. At an average construction cost of $175,000, the estimated payback period is 9.4 years — before accounting for the resale value the ADU adds, which an appraiser determines from comparable sales in Sacramento and varies by market (often less than build cost).

Ways to Reduce ADU Costs in Sacramento