A non profit group has sued the city of Whittier, saying its law on garage conversions is too restrictive — in particular its requirements for replacement parking.

In the 14-page lawsuit, filed by Los Angeles-based Californians for Homeownership, Matthew Gelfand, the group’s attorney, said the city’s rules on garage conversions violates state laws easing the rules on those and second units, otherwise known as “granny flats.”

“Whittier is generally prohibiting the conversion of garages into dwelling units,” Gelfand said by phone Monday.

“They’re requiring homeowners to replace the garages with covered or enclosed parking,” he said. “But they’re entitled to convert their garages without replacing their parking.”

Whittier City Manager Jeff Collier, also by phone on Monday, disputed Gelfand’s interpretation of the law.

The city can’t require parking for the new unit created by the garage conversion — but it can for the lost parking, Collier said.

Collier also argued that current bills pending in the state Legislature would when a garage, carport or covered parking structure is demolished, ban a local agency from requiring that the parking spaces be replaced.

Both Senate Bill 13 and Assembly Bill 68 would, among other things, eliminate parking rules, according to their analyses by the state Legislature.

If that’s the case, Whittier’s current law must be legal, Collier said. Why else would the state Legislature be looking at making changes, he asked.

However, Gelfand said the bills would “drastically” expand the types of second units not required to add parking.

Collier also argued that easing parking rules would hurt quality of life in Whittier.

“If the city can’t require any replacement parking, everyone ends up parking in a driveway or on the street,” he said. “We’re concerned about the impact that will be throughout our community.”

Gelfand said the Legislature already has looked at that issue.

“I know cities lobbied to get language in the bill allowing some parking,” he said. “This was carefully considered by the Legislature.”

The lawsuit is the first, but probably not last to be filed by this group, which is investigating and contacting cities over their housing policies, Gelfand said.

A trial-setting conference is set for Dec. 10.