The need is particularly great today. The number of renters has surged over the past decade, with the country adding about one million renters a year since 2010 — about twice as many as the previous rental peak in the 1970s and ’80s, according to a 2017 report by Harvard’s Joint Center for Housing Studies.

Developers have responded with an apartment building boom. But since renters tend to have higher incomes than in years past — households making more than $100,000 a year accounted for a third of the growth in renters over the past decade — many of the newer units are in the pricey glass and steel buildings that have sprouted in downtowns across the country.

There are some indications that the rush of building is helping increase affordability, especially at the upper end of the market, where vacancies are rising and rents are falling. Still, low-income housing remains undersupplied. About half of renters pay more than 30 percent of their income on housing, and a quarter pay more than half.

In California, legislators have proposed a range of fixes, from more money for affordable housing to fewer building regulations and increased tenant protections. State Senator Scott Wiener, the author of a recently enacted law that makes it harder for cities to block housing developments, has followed up with several proposed bills that would, among other things, increase construction around train stations and other transit hubs.

At the federal level, Senators Maria Cantwell, Democrat of Washington, and Orrin Hatch, Republican of Utah, sponsored a proposal to increase the number of low-income housing tax credits by 50 percent.

For now, there is little to suggest the rental burden will get better anytime soon. Over the next decade the younger half of the millennial generation will move into their 20s and 30s, adding to the pool of renters. Over that same period, more than a million units of affordable housing financed by low-income housing tax credits and other government programs are set expire and shift to higher rents, according to the Joint Center.