In the past six years, 677,000 new housing units have been built in California. Over that same period the state population has barely budged. More homes for roughly the same number of people looks like progress. Is California finally turning the corner on its long-running housing crisis?

Not quite. A closer look reveals that demographic change—not population growth—is the main driver of housing demand. And while the surge in new construction is welcome, it has not yet translated into meaningful relief for households struggling with high costs.

California’s Vacancy Rate Has Not Gone Up

One might expect that adding 677,000 units in a state that has gained only 39,000 residents (DOF estimates for January 2019 and January 2025) would push up vacancy rates and ease cost pressures. But statewide owner-occupied vacancies actually declined from 1.2% to 0.8%, and rental vacancy rates are only 0.2% higher than they were in 2019. California’s rates remain below those in the rest of the nation. According to the American Community Survey, the state’s rental vacancy rate was 4.3% in 2024, compared to 5.9% in the rest of the nation. New units are being occupied quickly, and demand continues to grow—even without population gains.

How is this possible? Because the number of people sharing a household has been falling over the past five years. As a result, more units are needed to house the same number of people. This pattern is not unique to California: household sizes are shrinking nationally as well. But California households remain larger on average than those elsewhere in the country, suggesting a substantial unmet demand.

Demographics Are Driving Demand

Two long-term demographic trends are reshaping household size in California. First, birth rates have continued to decline: the number of households with children declined by 82,000 between 2019 and 2024, while the number without children increased by 722,000. Second, California’s population is aging rapidly. Older adults, particularly those at the most advanced ages, are more likely to live alone or in two-person households. As the senior population grows, so does the number of smaller households—and the demand for appropriately sized units.

These shifts mean that even with its population flat or slowly declining, California will require a steady stream of new housing to accommodate its changing demographics.

Housing Stress Remains Elevated

The share of households spending an outsized portion of their income on rent or mortgage payments continues to distinguish California from nearly every other state. Despite higher average household incomes, California has the highest share (14%) of homeowners who spend more than half of their income on housing costs, and the third-highest share (28%) of renters who do so. Vacancy rates and affordability metrics alike suggest that while supply has grown, it is not yet high enough to eliminate the state’s housing shortage.

A Bright Spot: More Young Adults Forming Households

One encouraging signal is a modest uptick in household formation rates among young adults—a group that has been disproportionately squeezed by California’s high housing costs. For years, young Californians have delayed leaving home, lived with roommates, or left the state altogether. This slight increase in the share of young adults heading their own households is an early and tentative sign that supply may be inching closer to meeting demand.

The Takeaway

California’s housing market is complex, and recent trends controvert any simple narratives—from “we’re building enough” to “nothing is working.” The state has made real strides in adding supply, and that supply is being used. But California’s housing shortage is deep: while five years of above-average construction represents meaningful progress, the state is reckoning with decades of underbuilding and the compounding effects of rising costs.

Moreover, demographic change ensures that demand will continue even as population growth stalls, and cost burdens remain a defining feature of California life. Sustaining the pace of construction—and directing it toward the types and locations of housing that meet evolving household needs—remains an urgent policy priority.