Honolulu Mayor Kirk Caldwell signed into law today a bill imposing a moratorium of up to two years on building permits for “monster” houses, giving the city Department of Planning and Permitting time to come up with permanent rules to deal with the growing phenomenon.

DPP will, for the most part, not approve building permit applications during the moratorium for houses that cover more than seven-tenths of a lot under Bill 110 (2017). For example, a 5000-square-foot lot could not have a living space that’s 3,500 square feet or larger.

The new ordinance does allow DPP to consider exceptions for larger dwellings if they meet a very specific set of requirements. They include at least two off-street parking stalls for a dwelling up to 2,500 square feet in size and more stalls based on size; no more than 2.5 bathrooms for lots up to 4,000 square feet and more depending on lot size; greater side and rear setback requirements; and no more than two wet bars and one laundry room per dwelling.

While the moratorium is for up to two years, DPP Acting Director Kathy Sokugawa said she expects to have a draft set of rules forwarded to the Council by the end of the year.

The bill, introduced by Councilman Ikaika Anderson, was prompted by concerns by residents in older Oahu districts who are troubled that their communities are being inundated by structures so large that they are out of character with their neighborhoods. They also argue that the houses overtax sewer and water lines, drainage ways, parking and other infrastructure.

There’s also concern that the homes are being used as illegal apartments, boarding houses or vacation rentals, or for other non-permitted businesses.

Opponents of a moratorium, however, have argued that the restrictions are too onerous and could affect construction of less obtrusive houses at a time when Oahu is in the midst of a housing shortage, and of affordable units in particular.