WhatsAppHome additions are one of the most impactful — and most expensive — projects a Green Bay homeowner can take on. Whether you’re adding a master suite, sunroom, or second story, here’s what it actually costs in 2026.
Cost by Addition Type
Bump-out (50–100 sqft): $20,000–$45,000. Small extension off an existing room — common for breakfast nooks or expanded bathrooms. Single-room addition (200–400 sqft): $50,000–$120,000. New bedroom, family room, or sunroom built on a new foundation. Master suite addition (400–600 sqft): $90,000–$180,000. Bedroom + bathroom + closet built as a wing. Second-story addition (full footprint): $200,000–$400,000+. Doubles your usable space but requires major structural work.
What Drives the Cost?
Foundation work is the biggest variable — a frost-line-deep foundation in Wisconsin runs $15–$35 per sqft just for the footing and walls. Roof tie-ins, matching siding to existing, electrical and HVAC extensions, and plumbing all add up. Permits in Green Bay typically run $500–$2,500 depending on scope.
Will It Increase My Home Value?
Most well-executed additions in Green Bay add 50–80% of their cost back to home value. Master suite additions and kitchen expansions give the highest ROI. Sunrooms give the lowest because they’re often not included in livable square footage by Wisconsin appraisers.
Get a Real Estimate
Every addition is unique. We offer free in-home consultations across Northeast Wisconsin to walk your property, discuss what’s possible, and give you a realistic quote within 48 hours. Call (920) 367-1272.
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