Rancho Cucamonga, San Bernardino County

Room Addition Cost in Rancho Cucamonga, CA

Rancho Cucamonga remodeling costs are 10% belowthe California state average. Here's what a typical room addition costs in Rancho Cucamonga in 2026, based on a 300 sqf project.

Budget

$54,000

$180/sqf

Mid-Range

$94,500

$315/sqf

High-End

$148,500

$495/sqf

Cost breakdown

Foundation & Framing

30%$28,350

Roofing & Exterior

15%$14,175

Mechanical (HVAC, Electrical)

15%$14,175

Interior Finishes

20%$18,900

Windows & Doors

10%$9,450

Permits & Engineering

10%$9,450

Breakdown based on mid-range estimate of $94,500

Typical Timeline

3-6 months

Permits Required

Building permit, structural engineering, possibly zoning approval.

Remodeling in Rancho Cucamonga

Upscale Inland Empire city with newer housing stock. Mountain views drive premium pricing for some neighborhoods. One of the more desirable IE cities for renovation investment.

A room addition adds square footage and value to your home. Costs depend on whether it's a simple bump-out, a second story, or a full wing addition with plumbing.

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