Larkspur is poised to have the toughest smoking restrictions in Marin County after the City Council this week voted unanimously to bar residents from lighting up in most condominium and apartment units.

The ordinance will go into effect in May if the City Council gives its final approval April 20, City Manager Dan Schwarz said. However, building managers would have a year to phase in the rules, in part so smokers who want to move may do so without breaking their leases.

"(The ordinance) formalizes a higher level of recognition that second-hand and tertiary smoke is in fact a public health issue, and that if people do smoke they are impacting other people who don't want their own health jeopardized," Mayor Larry Chu said. "Common sense would dictate that you are cognizant of how you impact other people around you, but the fact that there is enough noncompliance of that really forces us into formalizing it into an ordinance."

Under the new rules approved by the council Wednesday, smoking wouldn't be allowed inside apartment and condominium units -- or on associated balconies or patios -- as well as in any residences with shared walls. However, landlords and condominium boards would have the option to seek exemptions for up to 20 percent of units, which would then be grouped together in a "smoking section."

That percentage makes it stronger than Novato's 2008 smoking ordinance, which introduced similar restrictions but allowed 50 percent of units in existing complexes to opt out and 25 percent of units in new developments to be designated for smoking.

Landlords have generally been receptive to the ordinance, and the only real opposition over the course of several public meetings came from a single smoker who showed up once to say she believed her neighbors were ganging up on her, Schwarz said.

"I got feedback from landlords that this was the trend anyway -- they're getting fewer and fewer smokers renting their spaces," Schwarz said. "Smokers do cost them a lot to clean up the units afterwards. There's a lot of expense in getting the smell out of the unit."

The ordinance also outlaws smoking at public sporting events, farmers markets, fairs and pageants, though not at parades.

"We didn't feel it was practical to stop people from smoking at the Fourth of July parade, for example, because if we weren't having a parade, it would be OK for them to be walking on the sidewalk and smoking," Schwarz said.

County of Marin's Department of Health and Human Services will field complaints and send out enforcement letters, as it does for Novato, said Bob Curry, a project coordinator for the county's Tobacco Related Disease Control Program.

Since Novato's ordinance went into effect, Curry said his department has handled about 30 complaints, mostly at businesses rather than housing complexes. All have been resolved at the county level without resorting to fines or legal action, he said.

"We will either talk to the person and sometimes we'll go visit a business to see if this is an ongoing issue," Curry said. "Then we will send a letter to the business and say, 'We've had some complaints,' and tell them what the policy is. . . . For those who don't know, usually all we have to do is let them know and they comply."

The Smoke-Free Marin Coalition and the Marin County Tobacco Related Disease Control Program are working with officials in Marin County, Tiburon and Fairfax on crafting similar legislation, Curry said.

Jennie Cook, a Larkspur resident and chairwoman of the smoke-free coalition, said her group hopes Larkspur's ordinance will serve as a model and encourage other municipalities to follow suit.

"We're very, very, very pleased," Cook said. "For some of the tenants here in Larkspur it's been years that they've been asking for help, and I've been talking to them this morning and they are just elated."