Mercer Island begins review of residential code draft

After months of discussion about gross floor area, tree retention, impervious surface and property values, the Mercer Island Planning Commission is preparing its recommendations on revisions to the city’s residential code.

The commission meets at 6 p.m. March 29 in the Mercer Island Community and Event Center to go over the first draft of the residential development standards, and will hold a public hearing at 6 p.m. April 5, also at the MICEC.

Planning Manager Evan Maxim said the goal of the code rewrite has been to address the concerns in the community about new residential development, and adopt some number of code changes that are “more on point” with what the community wants. A code with more consistency, clarity and a predictable permit process will also help builders and developers, he said.

Over the course of the public process, which kicked off in October, both city staff and members of the Planning Commission and City Council have learned that not all Islanders want the same things.

“Everyone has a different idea of what their community should look like in the future,” Maxim said.

Realtors, developers and property rights advocates say land values could be affected by some of the proposed changes, including changing the gross floor area limit from 45 percent to 40 percent, and placing a cap on home size for large lots based on zoning designation. Those who value greenery have been somewhat dismayed by a proposal to eliminate the limit on impervious surface, or hardscape, altogether, though that may be replaced by a more prescriptive landscaping requirement.

Overall, what the commission has heard is that new large homes in neighborhoods with small lots are “out of scale” with their surroundings, and that the standards should allow for more flexibility in home building so that new developments aren’t maxed out to the largest size possible, with the help of variances and deviations, for which the criteria are easily met. Impervious surface deviations are by far the most frequent deviation approved, according to the city.

The commission also heard a strong preference for tree retention, and is considering a requirement that 30 percent of trees be kept in plans for new homes, large remodels or division of land, with priority retention of large, healthy trees and a required tree permit for removal of large trees.

The commission has been looking at several tools that will hopefully address some of the concerns with home size and bulk. Larger side yard setbacks could increase the amount of light that reaches the houses of neighbors around a taller home. A ‘daylight plane’ concept, similar to the one adopted in the new Town Center code that requires stepbacks on upper floors, could reduce the physical appearance of larger houses.

Many of the issues with the code stem from the fact that it has not been updated regularly, Maxim said. Much of the code was written in the 1960s and rewritten in the 90s. Tools that worked at the time — such as the gross floor area limit, designed to prevent the building of ‘megahomes’ — haven’t held up.

“Generally, we assume there’s a 10-year building cycle, and we try to make tweaks before the next wave comes in,” Maxim said.

The city’s Development Services Group, led by Director Scott Greenberg, was set up for permit processing, not long range planning, though that changed with the Town Center code rewrite, which began in 2014, and the hiring of Maxim in 2016. Maxim said he is looking forward to being more proactive in making sure the city’s policies match what the community desires.

Maxim said that property values are considered in land use decisions. The gross floor area change would result in about an 11 percent reduction in allowed floor area.

“I don’t doubt that the change will depress the real estate market in the short term, but it will recover,” he said. “Some of the things we’re recommending, with trees and open space, might increase property value… because people value the forested, rural aesthetic of Mercer Island.”

Another change that arose from this process is shifting administrative appeals away from the Planning Commission to the Hearing Examiner. Mercer Island is the only city in the area that still had its Planning Commission involved in any quasi-judicial decisions, Greenberg said.

Planning Commissioner Daniel Hubbell said the commission’s involvement in some cases has been tricky as neighbors have to pass judgement on neighbors. Overall, Hubbell said that the code rewrite process has been deliberate and thorough. Though the Planning Commission members don’t always agree, “we all live on the Island and want what’s best for our community,” he said.

Land use policy dictates the character, makeup and density of the community, Hubbell said, and Mercer Island is a special case because of its topography and very distinct neighborhoods. He said the Planning Commission’s job is to “lay a groundwork that’s as complete as possible” to help the City Council make its decision on the residential code changes.

Before moving to Mercer Island, Hubbell lived in Newcastle, serving on its Planning Commission for six years and City Council for four years. He was also on the Mercer Island Design Commission for four years, helping with the Town Center code rewrite.

“In 13 years of public service, this is the best and most engaging dialogue I’ve had with the community,” he said. “We can’t make everyone happy. Success would be identifying concerns and making adjustments that will maintain the health of our community long-term.”

He said that the Town Center process was a learning experience for future land use and public engagement efforts.

“Typically, we only get the chance to make sweeping changes once every 10 years, and we’ve done it twice in the past 18 months,” he said.

Interested residents can comment at upcoming meetings or online. For more, see