How Much Does an ADU Cost in Fair Oaks?
Updated June 12, 2026 · Upside ADU
Quick answer
A detached ADU in Fair Oaks costs about $128,750–$444,960 turnkey in 2026, or roughly $258–$371 per square foot (design, permits, and construction included). A 750 sq ft 2-bedroom unit averages $193,125–$278,100; garage conversions and Junior ADUs cost less. Fair Oaks runs roughly 3% above the central-Sacramento baseline, driven mostly by site conditions and finish expectations in this submarket.
What does each ADU type cost in Fair Oaks?
Price is driven first by type, because type decides how much new structure you build. The ranges below are Fair Oaks-specific for 2026 — the regional market adjusted for this submarket's higher build costs.
Fair Oaks ADU cost by type — 2026 turnkey ranges
| ADU type | Typical size | $ / sq ft | Turnkey range |
|---|---|---|---|
| Detached ADU | 500–1200 sq ft | $258–$371 | $128,750–$444,960 |
| Garage Conversion ADU | 380–620 sq ft | $185–$288 | $70,452–$178,808 |
| Attached ADU | 450–850 sq ft | $247–$350 | $111,240–$297,670 |
| Junior ADU (JADU) | 220–500 sq ft | $206–$330 | $45,320–$164,800 |
| Multigenerational ADU | 600–1200 sq ft | $258–$381 | $154,500–$457,320 |
See also:Upside's published pricing · ADU builder in Fair Oaks
What does an ADU cost per square foot in Fair Oaks?
Smaller units cost more per foot — fixed costs like a kitchen, bath, utility hookup, and permit spread across fewer square feet. Here is a detached build at Fair Oaks pricing.
Fair Oaks detached ADU cost by size (2026)
| Size | Typical config | $ / sq ft | Estimated turnkey |
|---|---|---|---|
| 400 sq ft | Studio / JADU | $258–$371 | $103,000–$148,320 |
| 600 sq ft | 1 bedroom | $258–$371 | $154,500–$222,480 |
| 750 sq ft | 2 bedroom | $258–$371 | $193,125–$278,100 |
| 1000 sq ft | 2–3 bedroom | $258–$371 | $257,500–$370,800 |
What drives ADU cost up or down in Fair Oaks?
Fair Oaks runs roughly 3% above the central-Sacramento baseline, driven mostly by site conditions and finish expectations in this submarket.
Fair Oaks lots: Wooded, low-density lots around Fair Oaks Village and Madison Heights give plenty of room for a private detached build.
Local permitting: Fair Oaks permits through the County's Building Permits & Inspection Division — it's unincorporated, not its own city. What shapes a Fair Oaks build is the tree canopy: large wooded lots leave plenty of room for a detached unit, but tree-protection rules and, on rural parcels, septic capacity often decide exactly where it lands.
The single biggest cost lever is size: keeping a unit under 750 sq ft exempts it from local impact fees. Site conditions (slope, soil, utility runs) and finish level move the rest.
Know your Fair Oaks budget — get an exact, all-in number for your lot.
Free feasibility check, no commitment. We confirm site conditions, permit fees, and your build range before you sign anything.
What will an ADU in Fair Oaks rent for, and when does it pay back?
A typical Fair Oaks ADU rents for $1,700–$2,700 a month in 2026. Fair Oaks Village's desirable character supports premium rents and strong owner-occupant multigenerational demand, lifting both rental yield and resale value. Run your specific numbers with the calculator below, or see the full payback math in the ROI guide.
Tools & guides:ADU cost calculator · ROI & rent estimator · ADU rental income & ROI guide
How Fair Oaks ADU cost compares across the region
Fair Oaks sits in the Sacramento County market. The regional baseline is central Sacramento; foothill and estate submarkets (El Dorado Hills, Granite Bay, Folsom) run highest, while Galt, Woodland, and Citrus Heights run lowest. For the full regional cost breakdown and methodology, see our Sacramento ADU cost guide, or compare every city on the ADU cost by city index.
Figures are 2026 Fair Oaks-area market estimates, not a fixed quote. Your exact price depends on your lot, design, and finish level — we confirm it with a free feasibility check.
Sources & references
- Accessory Dwelling Units — official guidance — California Dept. of Housing & Community Development (HCD)
- Sacramento County Building Permits & Inspection Division — permits & fees — Sacramento County Building Permits & Inspection Division