Folsom, CA · Sacramento County
Attached ADU in Folsom
Upside ADU builds attached adus in Folsom, Sacramento County, for a $1,000 deposit with transparent fixed pricing and inspection-tied payments. A typical Folsom attached adu runs $118,800–$317,900 all-in, and we permit it through the City of Folsom Community Development Department end to end.
Folsom rules that affect a attached adu
In Folsom, an attached unit shares a wall and utility runs with your main home, which can cut trenching and site costs — useful on tighter lots where a fully detached build would crowd the yard. The City of Folsom Community Development Department reviews it as new attached square footage.
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 attached 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 attached 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 attached adu cost snapshot
An attached ADU connects to your existing house but functions as a fully separate dwelling. It shares utilities and a wall, which can reduce site and trenching costs versus a detached build. In the Sacramento County market that prices out to about $264–$374 per square foot, or $118,800–$317,900 for a finished, permitted unit. A typical Folsom attached adu rents for $1,900–$3,000 a month.
| Size | Typical use | Folsom all-in cost (2026) |
|---|---|---|
| 450 sq ft | Studio / 1-bed, max cash-on-cash | $118,800–$168,300 |
| 650 sq ft | 1–2 bed, most popular | $171,600–$243,100 |
| 850 sq ft | 2–3 bed / multigen, max value | $224,400–$317,900 |
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
$264–$374 / 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.
Attached 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 attached 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.
Attached ADU in Folsom — FAQs
A attached adu in Folsom typically runs $118,800–$317,900 turnkey in 2026, based on $264–$374 per square foot for the Sacramento County market. We confirm your exact number with a free feasibility check.
Folsom attached 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 attached 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.
An attached ADU shares at least one wall with your main house; a detached ADU is a standalone structure. Attached units can be cheaper to build (shared utilities, less site work) while detached units typically rent higher and add more resale value.
Attached 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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