If you're planning a custom home in Paradise Valley, one number governs almost everything about its size: Floor Area Ratio (FAR). Paradise Valley caps total building area at 25% of a lot's net area — so on a one-acre lot you can build roughly 10,890 sq ft under roof. Here's how that works, what counts, and what else shapes the final size.
What is Floor Area Ratio (FAR) in Paradise Valley?
Floor Area Ratio is the maximum building area allowed on a lot, expressed as a percentage of the lot's size. For Paradise Valley's residential zoning districts (R-175, R-43, R-35, R-35A, R-18, and R-18A), the Town requires a FAR of 25%. It's one of the key rules that keeps Paradise Valley an estate community rather than a high-density one.
What counts toward FAR?
This is where buyers are most often surprised: FAR is broader than "living area." It counts essentially everything under roof:
- The roofed first-floor footprint and any second story
- Garages
- Covered patios and porches, ramadas, and porte-cocheres
- Roof overhangs
- Accessory structures (guest houses, casitas)
- Covered courtyard or trellis areas
So a home with a large garage and generous covered outdoor living "spends" more of its FAR than the interior square footage alone would suggest.
How to calculate your buildable area
The formula is simple:
Net lot area × 25% = maximum building area
A one-acre lot (43,560 sq ft) × 0.25 = 10,890 sq ft. Here's how that scales across common Paradise Valley lot sizes:
| Lot size | Net area (approx.) | Max building area (25% FAR) |
|---|---|---|
| ½ acre | 21,780 sq ft | ~5,445 sq ft |
| 1 acre | 43,560 sq ft | ~10,890 sq ft |
| 1½ acres | 65,340 sq ft | ~16,335 sq ft |
| 2 acres | 87,120 sq ft | ~21,780 sq ft |
Every lot in our directory runs this calculation automatically: the Dream Home Estimator applies the 25% FAR to that specific parcel and pairs it with a build-cost range, so you can see a realistic home size before you buy. Browse vacant lots in Paradise Valley to try it, or see new construction homes for sale in Paradise Valley if you'd rather buy finished.
Does a basement count toward FAR?
Often, no — and that's a meaningful advantage. A fully subterranean (below-grade) basement generally does not count toward FAR, which means it can add finished square footage beyond the 25% cap. But exposed portions — a walkout wall, or light and window wells — can count, and the treatment gets nuanced on hillside lots. We cover this in depth in how a basement adds square footage in Paradise Valley.
What else limits how big you can build?
FAR sets the ceiling, but it's not the only rule. The final, usable size is also shaped by:
- Setbacks from every property line
- Height limits — generally about 24 feet, measured to natural or finished grade
- Hillside ordinance restrictions on sloped lots
- Washes, easements, and drainage requirements
Because of these, the FAR figure is a maximum, not a guarantee. For most residential lots the 25% cap applies, but some districts or special approvals may differ.
The bottom line
For a Paradise Valley lot, start with the math — net area × 25% — then subtract for setbacks, height, and terrain. That tells you the realistic size of the home you can build before you ever hire an architect. Final buildable square footage can vary, so an architect or design professional must determine the exact allowable size for a specific lot; our estimates are intended for planning purposes only.
Official Town of Paradise Valley references: Article 10 — Height & Area Regulations and the Floor Area Ratio (FAR) Certification.
Thinking about a specific parcel — or a teardown you'd rebuild? See how to find a teardown lot in Paradise Valley, or a member of our team can pull the FAR-based buildable area for any lot you're considering.
Frequently asked questions
- What is the floor area ratio in Paradise Valley?
- Paradise Valley's Floor Area Ratio (FAR) is 25% for its residential zoning districts. That means the total building area under roof cannot exceed 25% of the lot's net area. On a one-acre lot (43,560 sq ft) that's a maximum of about 10,890 sq ft.
- How big of a house can I build on a one-acre lot in Paradise Valley?
- About 10,890 sq ft of total building area (43,560 sq ft × 25%). That figure counts living space, garages, covered patios, and other roofed areas — not just interior living space — and can be reduced further by setbacks, height limits, and hillside rules.
- What counts toward Floor Area Ratio in Paradise Valley?
- FAR is broader than living area. It includes the roofed first-floor footprint, any second story, garages, covered patios and porches, roof overhangs, ramadas and porte-cocheres, accessory structures, and covered courtyard or trellis areas. For most residential lots the cap is 25%, though some districts or special approvals may differ.
- Does a basement count toward FAR in Paradise Valley?
- Generally, a fully subterranean (below-grade) basement does not count toward FAR, so it can add finished square footage beyond the 25% cap. Exposed portions — a walkout, or light and window wells — can count, and the treatment is nuanced on hillside lots. Confirm any basement plan with the Town and your architect.
- How tall can a house be in Paradise Valley?
- Paradise Valley generally limits residential building height to about 24 feet, measured from natural or finished grade (whichever is more restrictive) to the highest point of the roof. Hillside lots carry additional restrictions.
Talk to a Paradise Valley specialist
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