Somerville has overhauled its zoning regulations for the first time since 1990, altering myriad rules—some dating as far back as the 1920s—covering everything from parking and bike storage to the density and affordability of new projects to the construction of tiny homes in backyards.

The regulatory heavy-lift was seven years in the making, and the Somerville City Council passed it on December 12. The rules take effect immediately, and the city plans to post the specifics online soon.

Broadly speaking, they include a suite of a regs designed to encourage residents to avoid cars. The overhaul repeals minimum parking requirements for most of Somerville, for instance, and adds new maximum levels of parking for areas in walking distance of the T, the effects of which will become more pronounced once the Green Line extension through town is finished early next decade.

Moreover, parking in the city’s densest areas will have to be in commercial parking facilities (e.g., garages) under the rules, which also establish new minimum bike-storage requirements for developments.

The overhaul, too, is designed to encourage denser development, an apparent must for the entire Boston region if it’s to alleviate its housing shortage. Somerville will now allow backyard cottages, including tiny houses. And the new rules provide bonuses for building denser on larger lots.

Bonuses will also apply to developments that are designated 100 percent affordable. What’s more, the city will now require the majority of new development to provide 20 percent of units as affordable housing.

Finally, Somerville’s zoning overhaul includes new building standards designed to help the city toward its goal of going carbon-neutral by 2050. And it aims to make zoning regs easier to understand through clearer language and better graphics.

Joe Curtatone, the city’s recently re-elected mayor, praised the overhaul in a statement.

“For years we have steadfastly worked, as a community to ensure that we have the best possible zoning ordinance that meets the goals and expectations of our residents and businesses, that enables us to expand affordable housing, jobs, development, and so much more to move our community forward while ensuring residents of all backgrounds can afford to stay, and build their homes and businesses here,” he said.

Whether the overhaul leads to the sort of denser development that might bring down housing costs by increasing supply remains to be seen. Stay tuned.