Short answer. New home sales (Census Bureau) count first-sale single-family homes built by builders; existing home sales (NAR) count all subsequent transactions of previously-owned homes. Existing sales are 6-10× larger by volume in any given year.
The two series are fundamentally different and complementary.
New home sales (U.S. Census Bureau)
- What it measures: first sales of new single-family homes by builders. The transaction is counted at the signing of the sales contract, not at closing.
- Source: Survey of Construction, a probability sample of 900 building-permit places.
- Reporting frequency: Monthly, seasonally adjusted annual rate (SAAR).
- Typical annual range: 300K (2011 trough) to 1.28M (2005 peak).
Existing home sales (NAR)
- What it measures: closed transactions of previously-owned single-family homes, condos, co-ops, and townhomes.
- Source: Aggregated MLS data.
- Reporting frequency: Monthly, seasonally adjusted annual rate.
- Typical annual range: 1.99M (1982 trough) to 7.08M (2005 peak).
Why both matter
New construction is the leading-indicator series — builders respond to demand changes faster than the resale market because they're sizing inventory to forward expectations. Existing sales are the dominant volume series and the more reliable measure of overall household formation and migration.
For the full split history by year, see the market-share dashboard.
Sources
U.S. Census Bureau Survey of Construction; National Association of Realtors Existing Home Sales report; Freddie Mac Primary Mortgage Market Survey; National Bureau of Economic Research Business Cycle Dating Committee.