Buy vs Build House Calculator

About this calculator

A buy vs. build comparison adds up the total cost of two paths to homeownership: buying an existing home (purchase price plus renovation costs to bring it to the desired standard) versus building a new house on land you already own (construction cost per square foot plus permit and site-preparation fees). Comparing the two totals shows which route is actually cheaper for a given target home size and quality.

Homebuyers and self-builders run this comparison because the two paths involve very different cost structures — an existing home has a known purchase price but often hidden renovation needs (roofing, electrical, plumbing), while new construction has a more predictable per-square-foot cost but adds permit fees, site work, and typically a longer timeline before move-in. Builders and real estate agents also use similar cost-per-square-foot benchmarks when advising clients on land they already own versus resale inventory in their market.

This calculator takes the purchase price and renovation budget for an existing home, and the construction cost per square foot, home size, and permit costs for building new, then returns the total cost of each option side by side so you can see which is cheaper for your situation.