By Marc Stiles, Puget Sound Business Journal (subscription required)

The size of new houses on Mercer Island will be limited more than anywhere else in the region starting Nov. 1, when new restrictions that the city council approved on Tuesday take effect.

The council voted 5-1 to update the city's residential design standards and approved a new rule to protect mature trees.

The code update affects all of the 6,950 single-family lots on the island, which is a choice market for builders of new homes. The island's average household income of $183,200 is the Puget Sound region's second-highest behind Medina, according to Puget Sound Business Journal research.

New construction and remodeling projects can still be vested under the old code until the end of October, city spokesman Ross Freeman said.

After that, new homes won't be able to cover more than 40 percent of a lot, down from 45 percent. Maximum heights have been cut from 35 to 30 feet, and at least 30 percent of large trees must be kept when a lot under goes major construction. The rules also limit the amount of "hardscape" surfaces, such as decks and patios, to 9 percent of a lot.

Residents who pushed for the change raised concerns about how quickly the character of their neighborhoods have been changing, with old houses being replaced by larger ones.

While the city has been working on the update for about a year, critics say the city rolled out the new rules hither and yon, discussing different changes at different times. They were not discussed as a comprehensive package, according to the Master Builders Association of King and Snohomish Counties, which asked council members to slow down the process and consider their recommendations.

"This is a lose-lose. The (homebuilding industry) was not heard and the community's primary concerns were not addressed," David Hoffman, a government affairs staff member for the homebuilders, said after Tuesday's council vote.

People are still going to build big houses that will upset some neighbors, he said.