Home Addition Costs in Phoenix and Scottsdale: $200–$400 per Square Foot

A home addition in Phoenix or Scottsdale typically costs $200 to $400 per square foot for a professionally designed, permitted, and finished project. A 250-square-foot addition may range from $50,000 to $100,000; a 400-square-foot addition from $80,000 to $160,000; a 500-square-foot addition from $100,000 to $200,000; a 750-square-foot addition from $150,000 to $300,000; and a 1,000-square-foot addition from $200,000 to $400,000. Small additions can cost more per square foot because fixed costs like plans, engineering, permits, foundation, roofing, electrical, insulation, drywall, flooring, stucco, paint, HVAC, and inspections are spread over less space. A primary suite addition may cost $170,000 to $350,000 or more; a kitchen expansion $125,000 to $300,000 or more; a second-story addition $300 to $500 per square foot or more. Costs vary by room type, materials, structural changes, and site conditions. Permits are required from Phoenix or Scottsdale, with fees based on project size and value. Planning takes two to six weeks, design and engineering two to four months, city and HOA review one to three months, and construction four to nine months. Homeowners should set aside at least 10% of the budget for unexpected issues. Infinity Home Remodeling offers design-build services for Scottsdale and nearby areas.