Garage conversion · checked Oct 18, 2026
Garage conversion ADU fees in Sacramento: $3,327–$3,659 for a 400 sq ft garage
That’s $437 less than building the same 400 sq ft as a new detached ADU in Sacramento, and $562 less at 550 sq ft, the size you reach with the 150 sq ft expansion state law allows. Both sizes are under 750 sq ft, so there are no impact fees either way.
What changes
Why a conversion costs less in Sacramento
- Building permit fee (valuation table): $1,033 new vs $749 converted at 550 sq ft. From the City’s residential fee schedule, using its valuation table: $170.80 per sq ft of new living area, or $101.16 per sq ft for a garage conversion. Over $100,000 of valuation: $1,078 plus $0.006787 per dollar.
- Building plan review fee: $434 new vs $315 converted at 550 sq ft. From the same table; over $100,085 of valuation it is 42% of the building permit fee.
- Technology surcharge: $147 new vs $106 converted at 550 sq ft. 10% of the building permit and plan review fees.
- General Plan Fee: $244 new vs $146 converted at 550 sq ft. $2.60 per $1,000 of valuation; the City’s ADU estimate counts each started $1,000.
- Strong Motion Fee (state): $12 new vs $7 converted at 550 sq ft. Valuation × 0.00013.
- City Business Operations Tax (contractor-pulled permits): $0–$38 new vs $0–$22 converted at 550 sq ft. Valuation × 0.0004, charged only when a contractor applies for the permit; not charged to owner-builders.
Line by line: converted garage vs new detached ADU
2,000 sq ft main home (example assumption), law in force today. Garage sizes are examples: 400 sq ft is a typical two-car garage; 550 sq ft adds the 150 sq ft expansion.
| Fee | Garage, 400 sq ft | New detached, 400 sq ft | Garage + 150, 550 sq ft | New detached, 550 sq ft |
|---|---|---|---|---|
| Planning & zoning | ||||
| General Plan Fee | $107 | $179 | $146 | $244 |
| Planning inspection fee | $526 | $526 | $526 | $526 |
| Planning review fee | $263 | $263 | $263 | $263 |
| Building permit & plan check | ||||
| Building permit fee (valuation table) | $622 | $846 | $749 | $1,033 |
| Building plan review fee | $261 | $355 | $315 | $434 |
| Technology surcharge | $88 | $120 | $106 | $147 |
| Strong Motion Fee (state) | $5 | $9 | $7 | $12 |
| Fire Department administrative fee | $176 | $176 | $176 | $176 |
| Fire Department inspection | $294 | $294 | $294 | $294 |
| Fire Department plan review | $260 | $260 | $260 | $260 |
| Public works & encroachment | ||||
| Public Works review (deposit) | $205 | $205 | $205 | $205 |
| Utilities review (deposit) | $205 | $205 | $205 | $205 |
| Construction taxes | ||||
| City Business Operations Tax (contractor-pulled permits) | May apply$16 | May apply$27 | May apply$22 | May apply$38 |
| Construction Excise Tax | Est.$315 | Est.$315 | Est.$433 | Est.$433 |
| Residential Construction Tax (3+ bedrooms) | May apply$315 | May apply$315 | May apply$315 | May apply$315 |
| Impact fees | ||||
| Park Development Impact Fee | Exempt | Exempt | Exempt | Exempt |
| SAFCA flood control Development Impact Fee | Exempt | Exempt | Exempt | Exempt |
| Sacramento Transportation Authority mitigation fee | Exempt | Exempt | Exempt | Exempt |
| School district fee | ||||
| School fee (district; statewide cap shown) | Exempt | Exempt | Up to$2,959 | Up to$2,959 |
| Modeled total | $3,327–$3,659 | $3,754–$4,096 | $3,686–$6,982 | $4,233–$7,544 |
State law
What California guarantees for a garage conversion
A city must approve one ADU inside an existing accessory structure such as a garage, can’t require a setback for it, and can’t make you replace the parking you lose.
Gov. Code §66323(a)(1)
One accessory dwelling unit and one junior accessory dwelling unit per lot with a proposed or existing single-family dwelling if all of the following apply:
Gov. Code §66323(a)(1)(A)
may include an expansion of not more than 150 square feet beyond the same physical dimensions as the existing accessory structure
Gov. Code §66314(d)(7)
No setback shall be required for an existing living area or accessory structure or a structure constructed in the same location and to the same dimensions as an existing structure that is converted to an accessory dwelling unit or to a portion of an accessory dwelling unit
Gov. Code §66314(d)(11)
When a garage, carport, covered parking structure, or uncovered parking space is demolished in conjunction with the construction of an accessory dwelling unit or converted to an accessory dwelling unit, the local agency shall not require that those offstreet parking spaces be replaced.
Quoted from Government Code, Title 7, Division 1, Chapter 13 (Accessory Dwelling Units), incl. §66311.5 (opens in new tab), checked Oct 18, 2026.
FAQ
Questions about garage conversion in Sacramento
How much are the fees to convert a garage into an ADU in Sacramento?
Our model of Sacramento’s official fee schedules comes to $3,327–$3,659 for a 400 sq ft garage conversion and $3,686–$6,982 at 550 sq ft, with a 2,000 sq ft main home. A new detached ADU of the same size would be $3,754–$4,096 and $4,233–$7,544.
Is a garage conversion cheaper than a new ADU in Sacramento?
In fees, yes: $437 less at 400 sq ft and $562 less at 550 sq ft. Building permit fee (valuation table) is lower for a conversion. Building plan review fee is lower for a conversion. Technology surcharge is lower for a conversion.
Do I have to replace the garage parking?
No. When a garage is converted to an ADU, state law bars the city from requiring replacement off-street parking (Gov. Code §66314(d)(11)).
Does a garage conversion pay impact or school fees?
No impact fees: the unit is under 750 sq ft. School fees apply only above 500 sq ft; at 550 sq ft the statewide cap would be up to $2,959, and the district may charge less.
Not modeled yet
What these totals leave out
- Regional San and County sewer development fees (‘check with County’) and water development or meter fees aren’t modeled.
- The City’s ADU estimate shows park, flood-control and transportation impact fees at exactly 750 sq ft. State law (Gov. Code §66324(c)(1)) bars impact fees on an ADU of 750 sq ft or less, so we show $0 at that size.
- The STA transportation fee is quoted only at 750 and 1,200 sq ft, so other sizes over 750 sq ft show it as not modeled.
- Green Building fee ($1 per $25,000 of valuation), C&D recycling processing fee, hourly re-reviews and special district fees aren’t included.
More
Keep going
Sources
Official sources
Every figure comes from these documents; each line’s quoted text is on the Sacramento page.
- City of Sacramento Community Development DepartmentFees and Charges Collected on Residential Building Permits (CDD-0245) (opens in new tab)
- City of Sacramento Community Development DepartmentAccessory Dwelling Unit (ADU) Fee Estimate, New Construction (CDD-0419) (opens in new tab)
- City of Sacramento Community Development DepartmentBuilding Forms: FY 2026/27 fee adjustments (Resolution 2026-0121) (opens in new tab)
- California State Allocation Board (Department of General Services, OPSC)State Allocation Board item: 2026 adjustment to the Level I developer fee (meeting of January 28, 2026) (opens in new tab)
- California Legislative Information (leginfo.legislature.ca.gov)Government Code, Title 7, Division 1, Chapter 13 (Accessory Dwelling Units), incl. §66311.5 (opens in new tab)
- HCD via data.ca.govHousing Element Annual Progress Report (APR) data, Table A2: ADU building permits by year (opens in new tab)