Complete 2026 cost breakdown: construction, permits, financing, and expected rental ROI.
Calculate your Sacramento ADU cost →Building an ADU in Sacramento costs between $170,000-$400,000 for new construction, with per-square-foot costs averaging $250-$500. These figures include design, permitting, site preparation, and construction. The most affordable option is a garage conversion at $90,000-$200,000, while prefab/modular ADUs fall in between at $170,000-$340,000.
| Cost Category | Estimated Range |
|---|---|
| Architectural Plans | $3,000 – $15,000 |
| Permits & Fees | City fee estimate form CDD-0419 (rev. 7/12/2026), at a $170.80 per sq ft valuation: about $5,272 total for a 749 sq ft new detached ADU, $10,624 at 750 sq ft and $14,843 at 1,200 sq ft. Line items at 1,200 sq ft: building permit $1,790.36, plan review $751.95, fire administrative $176, fire inspection $294 ($0.11 per sq ft, $294 minimum), fire plan review $260, planning inspection $526, planning review $263, public works and utilities review $205 deposit each plus hourly, construction excise tax $945.60, general plan fee $533 ($2.60 per $1,000 of valuation), residential construction tax $315, technology fee $254.23. Not included: school district fees (paid to the district, form CDD-0226), regional sanitation and county sewer fees, and any water or sewer tap, housing or project-area impact fees. Optional ADU Zoning Review: $0 (was $117 before July 2026). Optional written fee estimate: $164 (form CDD-0278). Extra review time bills at $216 per hour for Building and $263 per hour for Planning |
| Impact Fees | City impact fees are zero for an ADU under 750 sq ft and switch on at 750 sq ft (CDD-0423; CDD-0419). At 750 sq ft: park development impact fee $2,617.50, SAFCA flood-control fee $1,575, Sacramento Transportation Authority mitigation fee plus 2% admin $1,154.64, about $5,347 together; at 1,200 sq ft: $4,188, $2,520 and $1,415.76. The citywide Transportation Development Impact Fee shows $0 at all three sizes, and the form notes park, SAFCA and STA fees may be lower in some infill areas. School district fees apply at any size and are collected by the district. The city's 'Reduction of Development Impact Fees' program is for deed-restricted affordable units, not a general ADU waiver |
| Site Prep & Foundation | $10,000 – $35,000 |
| Framing & Structure | $15,000 – $45,000 |
| Plumbing | $8,000 – $20,000 |
| Electrical | $5,000 – $15,000 |
| HVAC | $3,000 – $8,000 |
| Interior Finishes | $15,000 – $40,000 |
Quotes for the same ADU commonly vary 20–40% between builders. We pass your request to up to 5 local builders serving Sacramento, where we have them — free, no obligation.
Get Sacramento builder quotes →Permit fees in Sacramento are City fee estimate form CDD-0419 (rev. 7/12/2026), at a $170.80 per sq ft valuation: about $5,272 total for a 749 sq ft new detached ADU, $10,624 at 750 sq ft and $14,843 at 1,200 sq ft. Line items at 1,200 sq ft: building permit $1,790.36, plan review $751.95, fire administrative $176, fire inspection $294 ($0.11 per sq ft, $294 minimum), fire plan review $260, planning inspection $526, planning review $263, public works and utilities review $205 deposit each plus hourly, construction excise tax $945.60, general plan fee $533 ($2.60 per $1,000 of valuation), residential construction tax $315, technology fee $254.23. Not included: school district fees (paid to the district, form CDD-0226), regional sanitation and county sewer fees, and any water or sewer tap, housing or project-area impact fees. Optional ADU Zoning Review: $0 (was $117 before July 2026). Optional written fee estimate: $164 (form CDD-0278). Extra review time bills at $216 per hour for Building and $263 per hour for Planning. The review timeline is 60 days by law: the city must approve or deny a complete application within 60 days when there is an existing home on the lot, or the ADU is deemed approved (17.228.105(B)(4)(b)-(c), matching SB 543). If the ADU is filed with a permit for a new house the city may wait until the house is approved, and any delay you request stops the clock. Published targets (ADU portal, Step 5): optional zoning review 1-3 weeks; building plan review roughly 1.5-2 months, with review cycle 1 at 20 business days, cycle 2 at 15 and cycle 3 at 5, not counting your time to answer corrections. State law gives a 30-day decision for an application that uses a city-preapproved plan or one identical to a plan approved in the current building-code cycle (Gov. Code 65852.27(b)); ask the Building Division whether a Shelf Ready plan qualifies, with plan check: Electronic Plan Check through the city's online permit portal. A detached ADU needs no fire sprinklers if the main house is unsprinklered and the ADU, excluding garage, is 1,200 sq ft or less; an attached ADU is exempt if the house is unsprinklered, the addition is no more than 50% of the original and the total stays under 3,600 sq ft. One water service per lot: the ADU ties into the house's water and sewer lines and normally needs no separate meter (City Code 13.04.070). Rooftop solar may be required under the California Energy Code; SMUD offers a free service consultation (CDD-0423, CDD-0009). Impact fees are City impact fees are zero for an ADU under 750 sq ft and switch on at 750 sq ft (CDD-0423; CDD-0419). At 750 sq ft: park development impact fee $2,617.50, SAFCA flood-control fee $1,575, Sacramento Transportation Authority mitigation fee plus 2% admin $1,154.64, about $5,347 together; at 1,200 sq ft: $4,188, $2,520 and $1,415.76. The citywide Transportation Development Impact Fee shows $0 at all three sizes, and the form notes park, SAFCA and STA fees may be lower in some infill areas. School district fees apply at any size and are collected by the district. The city's 'Reduction of Development Impact Fees' program is for deed-restricted affordable units, not a general ADU waiver. Pre-approved plans: Yes, two programs. 1) Shelf Ready ADU Plans: three free city-designed detached plans, all-electric and built to the 2022 Residential Code, updated December 2025: studio 367 sq ft, one-bedroom 559 sq ft, two-bedroom 747 sq ft. Mirroring is allowed, other changes are not, and you supply the site plan. All three stay under the 750 sq ft impact-fee threshold. 2) AB 1332 Preapproved ADU Program for third-party detached plans (Gov. Code 65852.27): the process exists but the city's catalog listed no plans as of September 19, 2026. Either route still needs site-specific zoning and building review.
| 1-Bedroom Rent | $1,500-$1,850/month |
| 2-Bedroom Rent | $1,800-$2,250/month |
| Annual Rental Income (est.) | $20,100/year |
| Payback Period (est.) | 14.2 years |
| Short-Term Rental | Depends on which option the ADU was approved under. |
| Overall ROI Estimate | 5-10% gross rental yield on a $250,000-$400,000 detached build renting at $1,800-$2,250/mo; a $90,000-$200,000 garage conversion at $1,500-$1,850/mo can gross 9-20% (estimates before taxes, vacancy and financing) |
A typical ADU in Sacramento generates approximately $20,100 per year in rental income based on average 1-bedroom rents. At an average construction cost of $285,000, the estimated payback period is 14.2 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).
1. Garage conversions save 40-60% vs new construction since the shell already exists. Average cost in Sacramento: $90,000-$200,000.
2. Prefab/modular ADUs offer predictable pricing and faster timelines. Average: $170,000-$340,000.
3. Pre-approved plans — available in Sacramento, which can save $3,000-$10,000 in design costs and 2-3 months in review time. See which cities offer pre-approved ADU plans.
4. State grants — California's CalHFA ADU grant (up to $40K) is currently paused; check calhfa.ca.gov/adu for status and your state for active programs.
5. Get multiple bids — ADU contractor pricing varies 20-40% for the same project. We recommend getting at least 3 quotes.
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