Sacramento County, California
ADU Builder in Folsom
Upside ADU is a Folsom ADU builder serving all of Sacramento County. We design, permit, and build all 5 ADU types — detached, garage conversion, attached, junior, and multigenerational — for a $1,000 deposit, with transparent fixed pricing. Permits run through the City of Folsom Community Development Department, which we handle end to end.
Your Folsom ADU builder — from design to move-in
Excellent schools and a strong job base keep Folsom rents and resale values among the highest in the region.
We build every type of ADU in Folsom with one transparent, all-in price and a $1,000 deposit — the California legal maximum — then tie the rest of your payments to inspection-passed milestones so money only moves when verified work is done. When it's ready to rent, we'll connect you with a trusted local property manager.
Folsom lots: Empire Ranch and American River Canyon sit on sloped or canyon-edge parcels; Folsom Ranch lots are newer and flatter but HOA-governed.
Popular Folsom areas: Empire Ranch, Folsom Ranch, Briggs Ranch, American River Canyon.
- $1,000 deposit — the CA legal max
- Inspection-tied milestone payments
- All 5 ADU types built here
- Property-manager referral when you rent
Folsom ADU rules & limits
Folsom's Community Development Department applies 4 ft side/rear setbacks and a 16 ft height cap, but the city's hillside and master-planned (Folsom Ranch) lots often add grading, retaining, or fire-zone requirements we scope up front. HOA review is common south of Highway 50.
Statewide, every Folsom ADU under 750 sq ft is exempt from impact fees, detached units can reach 1,200 sq ft, and no replacement parking is required when you convert a garage. For the full Sacramento County rulebook — setbacks, height, and owner-occupancy by ADU type — see our Sacramento-region ADU rules & setbacks guide.
ADU services in Folsom
Folsom ADU cost & ROI
Folsom ADUs run about $137,500–$475,200 all-in in 2026, and a typical unit rents for $1,900–$3,000 a month. Folsom's job base and schools keep rents and resale values at the top of Sacramento County, so even higher site-work costs pencil out on appraised-value lift and premium rent.
See the full Folsom ADU cost breakdown by type and size, run your own numbers with the ADU cost calculator, or see the full payback and rent-comp math in our ADU rental income & ROI guide.
Estimate your ADU
Ballpark 2026 turnkey cost, financing, and rental return for your area.
Estimated turnkey cost
$275–$396 / sq ft · incl. design, permits & construction
Estimates only — 2026 regional ranges, not a bid. Your real price depends on site conditions, finishes, and your lot. We confirm with a free feasibility check.
Permitting & timeline in Folsom
Folsom ADU permits are issued by the City of Folsom Community Development Department. California law requires a decision within 60 days of a complete submittal, and pre-approved plan sets can shorten review to about 30 days. We prepare the full package, pull the permit, and manage every inspection so you never stand in line at a counter.
Plan on roughly 6–9 months end to end for a detached build: about 2–6 weeks of design, 4–10 weeks of permitting, and 12–16 weeks of construction. Garage conversions and junior ADUs move faster.
The Upside Guarantee
Your money is protected at every step
Sacramento homeowners were burned by builders who took huge deposits and vanished. We built Upside to be the opposite — structured so you're protected before, during, and after the build.
$1,000 down — the legal maximum
California caps a contractor's down payment at $1,000 or 10% of the contract — whichever is less. On an ADU that's $1,000, not the 30–50% other builders demanded. Everything after is earned.
Inspection-tied milestone draws
After the deposit you pay in defined draws — design, permit, foundation, framing, MEP, drywall, completion — each released only after that phase passes inspection.
Honest capacity & timelines
We only take on work we can actually deliver, with realistic schedules and references to completed local projects you can visit.
ADU projects in Folsom
Folsom feasibility starts with the topo: Empire Ranch and American River Canyon lots often need a grading and retaining plan before a slab can be set. South of Highway 50, the Folsom Ranch HOA review gets added on top of the city's. Every build is fixed-price, inspection-milestone funded, and backed by our written guarantee.
See completed builds, specs, and before-and-after photos in our Sacramento-region ADU project gallery.
ADUs in Folsom — FAQs
Most Folsom ADUs cost $137,500–$475,200 in 2026 depending on size and type, or roughly $275–$396 per square foot. A 750 sq ft detached unit runs about $206,250–$297,000 turnkey, with design, permits, and construction included.
Folsom ADU permits run through the City of Folsom Community Development Department. Folsom's Community Development Department applies 4 ft side/rear setbacks and a 16 ft height cap, but the city's hillside and master-planned (Folsom Ranch) lots often add grading, retaining, or fire-zone requirements we scope up front. HOA review is common south of Highway 50.
A typical Folsom ADU rents for about $1,900–$3,000 a month in 2026, with detached and larger units at the top of that range. Folsom's job base and schools keep rents and resale values at the top of Sacramento County, so even higher site-work costs pencil out on appraised-value lift and premium rent.
We're an ADU builder, not a property manager — but once it's built we'll connect you with vetted Sacramento County property managers we trust to lease and run it for you. Plenty of owners self-manage instead.
Nearby service areas
Popular ADU models
Costs & rules in Folsom
Start your Folsom ADU
Get a transparent quote and a free feasibility check for your Folsom lot.