The Rise of Co-Primary Residences: How Ultra-High-Net-Worth Families Are Redefining Where They Live.

The traditional model of the primary residence — one city, one address, the family home that anchors professional, social, and educational life — is increasingly obsolete for the ultra-high-net-worth individuals who sit at the top of the global wealth distribution. The combination of location-independent income (technology entrepreneurship, financial markets, real estate itself), private aviation that makes physical distance fungible, and the post-pandemic reappraisal of urban versus amenity-rich environments has produced a generation of wealthy individuals who maintain two, three, or more genuinely occupied residences and who decline to nominate any single one as definitively primary.

The practical consequences of this shift are substantial. Estate planning becomes more complex: domicile for inheritance and capital gains tax purposes requires careful analysis in multiple jurisdictions simultaneously, and the concept of "centre of vital interests" — the test used by most OECD tax treaties to determine tax residence for individuals who divide their time between countries — requires documentation of where one's most significant personal and economic relationships are actually located. A family that spends four months in London, three months in Miami, two months in Aspen, and three months in a Mediterranean villa will find that the question of where they are resident for tax purposes is neither simple nor free of risk.

The property market implications are equally significant. Ultra-prime real estate in a growing number of cities is being purchased by buyers who have no intention of spending more than 90–120 days per year in the property. This has implications for amenity offerings (properties must function equally well as serviced residences for brief visits and as fully equipped homes for extended stays), for staffing (the dual-key management model, in which a residential management company maintains the property in hotel-quality condition during owner absence and transitions it rapidly to full domestic operation on arrival, has become a specialist category), and for pricing (the marginal buyer is no longer constrained by the local labour market or school system, which means that pricing in co-primary markets is increasingly benchmarked against global alternatives rather than local comparables).