SB 1117 in Sacramento: ADU Impact Fees at 800, 1,000 and 1,200 Sq Ft, Before and After

From January 1, 2027, SB 1117 changes how impact fees are charged on an ADU over 750 sq ft: for the first two ADUs on a lot, only the area above 750 sq ft may be charged. This article applies that rule to the City of Sacramento, using the City's own ADU fee estimate, so you can see what it means for an 800, 1,000 or 1,200 sq ft ADU. For the law itself, see What SB 1117 changes for ADU impact fees.

The short answer

• Today, the City's estimate charges three impact fees on an ADU of 750 sq ft or more: the Park Development Impact Fee, the SAFCA flood-control fee and the STA transportation fee. On the City's own rates they come to about $5,600 at 800 sq ft, $7,000 at 1,000 sq ft and $8,100 at 1,200 sq ft.
• From 2027, if the City keeps its per-square-foot rates and charges them only on the area above 750 sq ft, the park and SAFCA fees drop by about $4,190 on every ADU over 750 sq ft.
• The STA fee is charged by size bracket, not per square foot, and the City has not yet published how it will apply SB 1117 to it.
• Permit, plan review and other processing fees do not change. School fees do not change.

Which City fees are impact fees

The City publishes an ADU fee estimate for new construction (form CDD-0419, revised July 12, 2026). Most lines on it are processing fees and taxes based on the permit valuation: the building permit, plan review, fire review, construction excise tax and similar. Those are not impact fees, and SB 1117 does not affect them.

Three lines are impact fees, and the form shows them as zero below 750 sq ft:

Impact fee	How the City's estimate charges it
Park Development Impact Fee	$3.49 per sq ft of the ADU
SAFCA Development Impact Fee (flood control)	$2.10 per sq ft of the ADU
STA Mitigation Fee (Measure A transportation), plus 2% admin	By size bracket: $1,132 up to 800 sq ft, $1,388 for 801 to 1,200 sq ft

The per-square-foot rates are what the City's 750 and 1,200 sq ft examples work out to; the STA brackets are SacDOT's single-family rates effective July 1, 2026. The City's Transportation Development Impact Fee is shown as not charged on ADUs. Park fees can be lower in some infill and incentive areas; the figures here use the standard rates on the form.

What you pay today

Using the City's rates, the three impact fees come to:

ADU size	Park	SAFCA	STA	Impact fees total
749 sq ft	$0	$0	$0	$0
800 sq ft	$2,792	$1,680	$1,155	about $5,627
1,000 sq ft	$3,490	$2,100	$1,416	about $7,006
1,200 sq ft	$4,188	$2,520	$1,416	about $8,124

The 1,200 sq ft row matches the City's form line for line; the 800 and 1,000 sq ft rows apply the same rates. The form also shows these fees at exactly 750 sq ft (about $5,347), although state law has exempted ADUs of 750 sq ft or less since January 1, 2026. If your plans land on exactly 750 sq ft, raise it at plan review.

What changes from January 1, 2027

SB 1117 says that for up to two ADUs on a lot, impact fees on an ADU over 750 sq ft are charged "only on the area in excess of 750 square feet of interior livable space." The City has not yet published a revised form. If it keeps charging park and SAFCA fees per square foot and applies them to the area above 750 sq ft, the numbers become:

ADU size	Area charged	Park + SAFCA today	Park + SAFCA from 2027	Difference
800 sq ft	50 sq ft	$4,472	about $280	about $4,193 less
1,000 sq ft	250 sq ft	$5,590	about $1,398	about $4,193 less
1,200 sq ft	450 sq ft	$6,708	about $2,516	about $4,193 less

The difference is the same at every size: it is the first 750 sq ft at $5.59 per sq ft. The cliff at 750 sq ft disappears; an 800 sq ft ADU now pays park and SAFCA fees on 50 sq ft, not on 800.

The STA fee

The STA fee works differently. SacDOT's own schedule says an ADU over 750 sq ft pays a share of what a new main house would pay, in proportion to the two floor areas, while the City's estimate charges the ADU its own size bracket ($1,155 or $1,416 with the admin fee). How either will apply the "area above 750 sq ft" rule has not been published. Until it is, budget the STA fee at today's figure; any change can only lower it.

A full example: 1,000 sq ft ADU in the City

• Impact fees today: about $7,006 (park $3,490, SAFCA $2,100, STA $1,416).
• Impact fees from 2027, with park and SAFCA on 250 sq ft and STA unchanged: about $2,813.
• Processing fees, permit and valuation-based taxes: unchanged, and on top of both figures.
• School fee: unchanged. A 1,000 sq ft ADU in Sacramento City Unified pays the district's residential rate on its full size ($5.38 per sq ft on the City's school fee sheet CDD-0226, about $5,380).

Choosing between sizes with the new rule? Our guide on what size ADU to build in 2026 and 2027 puts these fees next to build prices. If your lot is in unincorporated Sacramento County, Elk Grove or Roseville, the rules are different: see ADU impact fees in Sacramento County, Elk Grove and Roseville.

FAQ

Does SB 1117 lower the City's building permit fee?

No. Building permit, plan review and the other valuation-based charges are processing fees, not impact fees. SB 1117 only changes impact fees.

Should I wait until 2027 to pull my permit?

For an ADU over 750 sq ft the park and SAFCA difference is about $4,190. Whether waiting makes sense depends on when the City calculates fees on your application and what a delay costs you in rent or construction prices. Ask the City which date fixes the fees before you decide.

Is a 750 sq ft ADU exempt in Sacramento?

Under state law, yes: ADUs of 750 sq ft of interior livable space or less pay no impact fees. The City's 2026 estimate still lists fees at exactly 750 sq ft, so confirm the treatment at plan review.

Does this apply to a garage conversion?

Most garage conversions are under 750 sq ft and already pay no impact fees. A conversion over 750 sq ft follows the same rule as any other ADU. See our garage conversion cost guide.

Sources: SB 1117 (Chapter 809, Statutes of 2026) and Government Code 66311.5 as amended, from the California Legislature's official bill data; City of Sacramento ADU Fee Estimate CDD-0419 (rev. 07-12-2026), Residential Fees Estimate CDD-0246 (rev. 07-12-2026), ADU handout CDD-0423, School District Impact Fees CDD-0226; SacDOT Measure A (SCTMFP) fee schedule effective July 1, 2026. Figures from 2027 assume the City keeps its current rates and charges them on the area above 750 sq ft; the City has not yet published its revised method. Checked October 2026.