Folsom, CA · Sacramento County
Detached ADU in Folsom
Upside ADU builds detached adus in Folsom, Sacramento County, for a $1,000 deposit with transparent fixed pricing and inspection-tied payments. A typical Folsom detached adu runs $137,500–$475,200 all-in, and we permit it through the City of Folsom Community Development Department end to end.
Folsom rules that affect a detached adu
Folsom's mix of lots leaves room for a standalone backyard unit with its own entrance, kitchen, and bath — the highest-value, most-rentable ADU type. The City of Folsom Community Development Department reviews detached builds on the standard 60-day clock.
Local permitting: 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.
That's the detached adu-specific picture. For the full Sacramento County rulebook — every setback, height, and owner-occupancy detail — see our Sacramento-region ADU rules guide, and learn how the build type works statewide on our detached adu page.
Why Folsom homeowners pick Upside
- $1,000 deposit — the CA legal max
- Inspection-tied milestone payments
- We know the City of Folsom Community Development Department process
- Transparent, all-in Folsom pricing
- Property-manager referral when you rent
Folsom detached adu cost snapshot
A fully independent dwelling in your backyard with its own entrance, kitchen, and bath. Detached ADUs add the most property value and command the highest rents of any ADU type. In the Sacramento County market that prices out to about $275–$396 per square foot, or $137,500–$475,200 for a finished, permitted unit. A typical Folsom detached adu rents for $1,900–$3,000 a month.
| Size | Typical use | Folsom all-in cost (2026) |
|---|---|---|
| 500 sq ft | Studio / 1-bed, max cash-on-cash | $137,500–$198,000 |
| 850 sq ft | 1–2 bed, most popular | $233,750–$336,600 |
| 1200 sq ft | 2–3 bed / multigen, max value | $330,000–$475,200 |
Dial in your own number with the ADU cost calculator.
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.
Detached 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 detached adu is fixed-price, funded on inspection-passed milestones, and backed by our written guarantee.
Browse finished builds and specs in our ADU project gallery.
Detached ADU in Folsom — FAQs
A detached adu in Folsom typically runs $137,500–$475,200 turnkey in 2026, based on $275–$396 per square foot for the Sacramento County market. We confirm your exact number with a free feasibility check.
Folsom detached adu permits are handled by 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. We prepare and submit the full package and manage inspections.
A detached adu in Folsom rents for about $1,900–$3,000 a month in 2026 depending on size and finish. 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.
A detached ADU in the Sacramento region typically runs $165,000–$500,000 in 2026, or roughly $250–$360 per square foot turnkey (design, permits, and construction included). A 750 sq ft 2-bed/1-bath lands around $230,000–$300,000 at mid-range finishes.
State law allows detached ADUs up to 1,200 sq ft. Units under 750 sq ft are exempt from impact fees, which is why many Sacramento homeowners build right at that threshold for the best cost-per-rental-dollar.
Plan on about 6–9 months end to end: 2–6 weeks design, 4–10 weeks permitting (as fast as 30 days with pre-approved plans), and 12–16 weeks construction.
Detached ADU near Folsom
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Not sure which type fits your lot? See all ADU services in Folsom or compare every build type on our ADU services hub.
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