Does a smaller house cost less per square foot to build?
Published
Summary
Usually not. A smaller house costs less in total, but some costs don't shrink along with the floor plan, so the price per square foot tends to rise as the house gets smaller. How the square footage is counted matters too, since Census measuring rules leave out garages, porches and unfinished basements.
Six costs that may not shrink with the plan
In NAHB's 2024 cost survey, the average house carried these line items:
- building permit fees: $7,640
- impact fee: $6,367
- water and sewer fees and inspections: $6,260
- architecture and engineering: $6,480
- appliances: $7,499
- driveway: $9,635
That adds up to $43,881. Spread across the survey's average house of 2,647 square feet, it's about $16.60 a square foot. Put the same $43,881 on a 1,500-square-foot house and it's about $29.30, so these six lines alone add close to $13 to every square foot.
The math assumes none of the six gets any smaller. How much they actually shrink depends on how your local fees are set, which appliances you pick and how long the driveway is.
What counts as a square foot
The Census Bureau counts finished floor space only. Garages, carports, porches, unfinished attics and utility rooms, and the unfinished part of a basement are left out.
It also measures from the outside of the walls. When a builder reports an interior measurement, Census multiplies it by 1.08, so a house that measures 2,000 square feet inside counts as about 2,160. Divide the same bid by the larger number and the price per square foot comes out about 7% lower, which can make one builder look cheaper than another when the two just measured differently.
The house behind the $162 figure
Half of the 1,005,000 single-family homes completed in 2025 had less than 2,142 square feet of floor area. The average house in NAHB's survey was about 500 square feet larger than that, so the $162-a-square-foot figure already describes a fairly big house.