Frequently Asked Questions

Housing affordability measures whether a household can comfortably pay for housing. The most common standard is the 30% rule: housing is considered affordable if it costs no more than 30% of a household's gross income.

The 30% rule is a guideline from HUD stating that households spending more than 30% of gross income on housing costs are 'cost-burdened.' Those spending over 50% are 'severely cost-burdened.' This standard has been used since the 1980s.

Rent burden is the percentage of a renter's income that goes toward rent. The national median rent burden is approximately 33.8%. In expensive metros like Miami and Los Angeles, median rent burden exceeds 40%.

Our affordability score (0–100) combines multiple factors: price-to-income ratio, rent burden percentage, homeownership rate, year-over-year price changes, and income growth. Higher scores indicate more affordable metros.

The price-to-income ratio divides the median home price by the median household income. A ratio of 3.0 or below is historically considered affordable. The national average has risen from about 3.5 in 2000 to nearly 5.0 in 2025.

Approximately 30% of all U.S. households — and nearly half of all renters — are cost-burdened, spending more than 30% of income on housing. That's roughly 40 million households.

Multiple factors contribute: decades of under-building (especially 2008–2020), restrictive zoning, rising construction costs, institutional investors buying homes, stagnant real wages relative to housing costs, and limited public housing investment.

Estimates of the national housing shortage range from 3.8 to 7.2 million units, depending on methodology. Freddie Mac, the National Association of Realtors, and Up for Growth have published widely-cited estimates.

Research consistently shows that housing costs are the strongest predictor of homelessness rates. Cities with higher median rents and lower vacancy rates have proportionally more people experiencing homelessness.

Mortgage denial rates range from about 8% in the most accessible markets to over 20% in expensive metros. Denial rates are also significantly higher for Black and Hispanic applicants, reflecting systemic inequities in lending.

The Home Mortgage Disclosure Act (HMDA) requires lenders to report data on mortgage applications, including approval/denial decisions, loan amounts, and demographic information. It's the primary source for studying mortgage lending patterns.

Building permits are authorizations from local governments for new construction. They're a leading indicator of housing supply. Areas with more permits per capita tend to have more stable prices and better affordability over time.

The eviction rate measures the number of eviction filings per 100 renter households annually. National averages are around 3–5%, but some metros exceed 8%. High eviction rates indicate housing instability and inadequate tenant protections.

In many expensive metros, essential workers (teachers, nurses, firefighters, EMTs) cannot afford median rents or home prices on their salaries alone. For example, a teacher earning $55,000 would need to spend over 50% of income on rent in cities like San Francisco or New York.

The homeownership rate is the percentage of occupied housing units that are owner-occupied. The national rate is approximately 65.5%, down from a peak of 69% in 2004. It varies dramatically by metro, from 32% (New York) to over 70% (many Midwest cities).

The pandemic triggered dramatic changes: remote work shifted demand to suburbs and smaller cities, home prices surged 30–40% in many metros, and mortgage rates rose from 3% to nearly 7%, making monthly payments roughly 60% more expensive.

The Federal Housing Finance Agency (FHFA) House Price Index tracks changes in single-family home values based on data from Fannie Mae and Freddie Mac mortgages. It's one of the most comprehensive measures of U.S. home price trends.

We use publicly available data from the U.S. Census Bureau (ACS), HUD, FHFA, HMDA, Bureau of Labor Statistics, and various research organizations. All data sources are cited on individual pages.

Most of our data reflects the latest available annual estimates. Census and ACS data typically has a 1–2 year lag. Home price indices and mortgage rates are updated more frequently. We aim to refresh all data quarterly.

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The breakeven point is when the total cost of owning (mortgage, taxes, insurance, maintenance, minus equity built) equals the total cost of renting over the same period. In many metros, this is now 7+ years due to high prices and rates.

Restrictive zoning (single-family only zones, minimum lot sizes, height limits) limits housing supply. Research estimates that zoning restrictions add 20–50% to home prices in many coastal cities by constraining new construction.

Since 2010, institutional investors have purchased an increasing share of single-family homes, particularly in Sun Belt metros. While they represent only 2–3% of total housing stock nationally, their concentration in specific markets can significantly impact affordability.