Why Housing Affordability Has Become So Complicated

The 30% Rule and Why It Falls Short Today

For decades, the rule of thumb was simple: spend no more than 30% of your gross income on housing. That guideline shaped federal housing policy and lender underwriting alike. But in today's market, following that rule is increasingly difficult — and in many U.S. cities, effectively impossible for middle- and lower-income households.

The problem isn't just that home prices are high. It's that multiple cost layers have expanded simultaneously. To understand why, it helps to look at each force separately — and then see how they interact. For a broader view of the forces that set prices in the first place, see how the housing market actually works.

The Four Cost Layers Squeezing Buyers

Purchase price and mortgage payments are the most visible layer. Home values appreciated rapidly in the early 2020s, and while some markets have since softened, prices remain elevated by historical standards in most regions. At the same time, mortgage rates rose sharply from the record lows seen in 2020–2021, meaning buyers now pay substantially more each month for the same loan amount. Mortgage rates and home affordability are deeply connected — and that relationship catches many first-time buyers off guard.

Property taxes are the second layer. As assessed home values rise, so do annual tax bills — often on a lag. Homeowners in some counties have seen tax bills climb significantly even after purchase, adding hundreds of dollars per year to effective housing costs.

Homeowners insurance has become a growing affordability factor, particularly in regions exposed to climate-related risks like flooding, wildfires, and hurricanes. Premiums have increased materially in states such as Florida, California, and Louisiana, and in some areas, coverage has become difficult to obtain at any price.

Maintenance and HOA costs round out the picture. Older housing stock requires ongoing upkeep, and inflation has raised the cost of materials and labor. Homeowners association fees, where applicable, add another fixed monthly obligation that lenders account for during underwriting.

Supply Shortfalls and the Wage Gap

Underlying all of these cost pressures is a fundamental supply imbalance. The U.S. has underbuilt housing relative to population and household formation for much of the past two decades. Zoning restrictions, labor shortages in construction, and rising materials costs have all constrained new inventory. When supply is limited and demand remains steady or grows, prices don't fall easily — even when buyers pull back.

Meanwhile, wage growth — while real — has not matched home price appreciation in most major metropolitan areas. A household earning the median income today can qualify for a meaningfully smaller home than a similarly situated household could afford a decade ago. This is the core of the affordability crisis: it's not just that homes cost more in dollar terms, but that incomes haven't stretched far enough to compensate. What drives home prices up and what pulls them down explores these dynamics in greater depth.

Affordability Looks Different for Renters

Renters face their own version of the affordability squeeze. Rental prices surged in many markets, driven partly by demand from would-be buyers who couldn't afford to purchase. While rent growth has moderated in some areas as new apartment supply came online, asking rents in most cities remain well above where they were five years ago.

For renters weighing a transition to homeownership, the calculation is especially complex. Down payment requirements, closing costs, and monthly ownership expenses can feel prohibitive even for households with stable incomes. The full picture for renters involves weighing both short-term flexibility and long-term cost trajectories — neither path is straightforwardly affordable right now in most markets.

What 'Affordable' Actually Requires Going Forward

Solving the affordability problem isn't a single-lever fix. Expanding housing supply through zoning reform, increased construction, and support for workforce housing developments addresses the inventory gap. Policy interventions that support down payment assistance and first-generation buyer programs can lower entry barriers without distorting prices further.

For individual households, understanding affordability means going beyond the listing price. Factoring in taxes, insurance, and maintenance alongside the mortgage payment gives a far more accurate picture of what a home will actually cost each month. Navigating the home purchase process requires that kind of comprehensive cost awareness at every step.

Affordability is ultimately a relationship between income, costs, and availability — and right now, all three are out of alignment for a significant share of American households. Recognizing the complexity is the first step toward navigating it with clear eyes.