Home Addition Cost: What to Expect
Home additions typically run $50,000–$200,000+ nationally, with most standard room additions averaging around $100,000. The range is enormous because additions can be anything from a simple bump-out to a full second story. Here's how the cost breaks down.
What drives home addition costs
Understanding what moves the price helps you evaluate whether a quote is genuinely high — or just reflects your specific project's scope.
Square footage — the primary driver of material and labor cost
Foundation type — slab, crawl space, or basement
Whether the addition requires plumbing, kitchen, or bathroom rough-in
Structural complexity — connecting to existing load-bearing elements
Finish level — builder-grade vs. matching existing home quality
A fair quote is about more than the total price
A lower total can actually represent more risk — if it omits items a complete quote should include. Here's what to verify regardless of price.
Regional pricing variance: Renovation costs vary significantly by location. Markets like New York City, San Francisco, and Boston typically run 30–50% above national averages, while rural Midwest and Southeast markets often run 15–25% below. Labor costs are the primary driver of regional differences.