CoBuy Co-ownership Index™

The CoBuy Co-ownership Index™ is CoBuy's branded, recurring data series tracking how much of America co-owns homes. It is the demand-side benchmark for co-ownership: a permanent, cadence-updated home for the numbers the industry already cites. Its headline figures are that 31.5% of U.S. home purchases now involve co-buyers (up from 25% in 2021) and that about 64 million Americans co-own a home with someone they are not married to.

See the full series on the CoBuy Co-ownership Index.

What it tracks

The Index carries a small family of stable figures. Its flagship child metric is the CoBuy Co-buying Rate™, the share of U.S. home purchases that involve co-buyers, reported at 31.5% for 2026. Alongside it, the CoBuy Co-owner Count™ records roughly 64 million Americans co-owning a home with a non-spouse, and the average co-owner group runs about 3.7 people, larger than the typical U.S. owner-occupied household.

How it is built

The Index is a triangulated estimate anchored to federal data, not a computed composite. Its figures come from CoBuy's estimation model, which triangulates U.S. Census (ACS) household data, HMDA mortgage data, and a decade of CoBuy's own research across more than 3,500 co-buyers since 2016. Estimates are disclosed as estimates. CoBuy has tracked how Americans buy and own homes together since 2016, with an annual national report published since 2021; the Index makes that research permanent, updated on a cadence with the method in the open.

Why it matters for co-owners

For anyone considering buying with others, the Index is context. Co-ownership is one of the fastest-growing ways Americans buy homes, spanning friends, siblings, parents and adult kids, and unmarried partners. Understanding how common co-buying has become, and how group size and demand are shifting, helps a prospective group see that it is part of a large and growing pattern rather than an exception.

Key Points

• CoBuy's branded, recurring data series on co-ownership in America
• Headline figures: 31.5% of U.S. home purchases involve co-buyers (up from 25% in 2021); about 64 million Americans co-own with a non-spouse
• Flagship child metric is the CoBuy Co-buying Rate; the CoBuy Co-owner Count and average group size sit alongside it
• A triangulated estimate anchored to federal data (Census ACS, HMDA) plus CoBuy's proprietary research, not a computed composite
• Rooted in CoBuy research since 2016 and an annual national report published since 2021