Your home is your castle – unless you smoke

City officials in San Rafael, California have adopted an ordinance that makes it illegal for residents to smoke in their homes if they share a wall with another dwelling.

The ban applies to not only renters but owners, too.

The ban applies to condos, co-ops, apartments, and multifamily residences with three or more units. The ordinance is believed to be the most stringent in the nation against smoking in homes.

“It doesn’t matter if it’s owner-occupied or renter-occupied,” said Rebecca Woodbury, an analyst at the San Rafael City Manager’s office. “We didn’t want to discriminate. The distinguishing feature is the shared wall.”

Woodbury says that studies show that second-hand smoke can seep through ventilation ducts, walls, and cracks. A UCLA study found that California property owners paid about $18 million a year to clean apartments that once had tenants who smoked living there.

“It depends on a building’s construction,” Woodbury told ABC News. “But it does affect the unit next door, with the negative health impacts due to smoke.”

Other property managers are getting stricter about permitting smoking in apartments. For example, Related Companies became the first developer and property owner this summer to ban smoking in all 40,000 of its rental residences throughout 17 states.

“There are more people who want to live in smoke-free environments than there are apartments available,” said Jessica Scaperotti, a spokesperson for Related. “Demand far exceeds supply.”

But others view the bans on smoking inside homes as too stringent.

“I don’t believe it’s rooted in science,” said George Koodray, New Jersey state coordinator for Citizens Freedom Alliance and the Smoker’s Club, who calls the California ban “mischievous.” “Someone smoking in a sealed apartment endangers the health of others in the building? The science for that is spurious at best.”