New limits on the construction of so-called "monster homes" will take effect immediately after Honolulu Mayor Kirk Caldwell allowed a regulatory measure to become law without his signature.

Caldwell said he supports the effort at regulating monster homes --the large, multi-bedroom buildings in residential neighborhoods that have generated complaints from across Oʻahu.

The good news, Caldwell said, is that well-publicized monster homes, including one in Kalihi described as having 20 bedrooms and inadequate on-site parking, will no longer be allowed under the latest changes.

But the mayor expressed disappointment that his administration's bill for the same purpose wasn't given a hearing. Instead, he said the council passed a measure that he described as difficult to implement and enforce.

"I believe the bill we submitted was bascially lean and tight, easy to implement, not a lot of discretion," Caldwell said at a Wednesday press conference. Inspectors would have an easier time determining if permits can be issued under the administrationʻs bill, he argued.

He said he expressed his concerns in a letter informing the council of his decision and plans to work with the council on changes to the new regulations under Bill 79 to address the issues he's raised.

Kathy Sokugawa, the city's acting director of planning and permitting, welcomed the density limits in residential areas and minimum onsite parking requirements provided in the new rules.

But she said complications arise when the regulations get into details like limits on the number of bathrooms and wet bars and the location of laundry rooms based not by dwelling unit but by lots. She said there are many lots on Oʻahu with multiple houses.

At least one council member pushed back against the administrationʻs criticism.

“Few regulations and a lack of enforcement led to the proliferation of monster homes," said Council member Kymberly Pine in a statement issued after the mayor signed Bill 79.

"We worked with builders and homeowners to ensure we protected the public from illegal structures while not over-regulating the construction industry. They were satisfied with the bill. It’s time the Mayor stops making excuses. Please, enforce the laws and protect our kid-friendly neighborhoods,” said Pine. Pine has signaled her intent to run for mayor.

Mayorʻs Letter to City Council on ʻMonster Homesʻ Bill