Evanston’s zoning code specifies the amount of a residential lot that may be covered by an impervious surface. It also specifies how much of the lot may be covered by buildings. The issue came before City Council on Dec. 14, because one couple who sought a permit to build a deck found confusion reigned when it came to the City’s classification of a wooden deck in terms of lot coverage and impermeable surface calculations.

The solution proposed by the Plan Commission was to treat a wooden deck as “pervious,” provided it was of wooden slats and grass or dirt was underneath, but at the same time takes a deck into consideration when lot coverage is calculated.  

Traditionally, lot coverage and impermeable surfaces were treated as one and the same, said Jim Ford, chair of the City’s Plan Commission. “We are suggesting a change,” he said. “A deck impinges on a neighbor in a way that a patio does not,” he added, making a deck count as lot coverage under the proposed amendment, while a patio would not.

“We did consider this quite a while,” Mr. Ford said.

Director of Community Development Mark Muenzer said the issue went before the Zoning Subcommittee of the Plan Commission at least twice, and before the entire committee at least once. The committee determined that the City’s current interpretation of decks is wrong.

Matt Rodgers, chair of the City’s Zoning Board of Appeals, said, “I feel the solution that has been brought before you is not the best solution.” He expressed concern that a change to lot coverage calculations would result in many Evanston homes being “thrown into noncompliance.”

Alderman Don Wilson, 4th Ward, echoed those concerns. If a grandfathered legal noncompliant home were to suffer deck damage, the owners could not rebuild the deck without a variance, he said. “Decks don’t last forever,” he said. “They all have to be replaced.”

Alderman Ann Rainey, 8th Ward, asked how the City treated a second-floor deck.

“Is it like a balcony?” asked Alderman Mark Tendam, 6th Ward.

“Yes, only more deck-like,” responded Ald. Rainey. “I think the City Council should consider decks pervious, depending on what’s under them.” Second-floor decks are considered pervious, if grass or dirt sits beneath them, said Mr. Muenzer.

The matter will not affect the application that spurred the initial debate. Lisa Pildes and her husband said they already “cut a deal with the zoning department. “This is not for us,” said Mr. Pildes.

“The experience this couple has had with the City is not probably ideal,” said Ald. Tendam. “What they have been told each time they appeared” before various City bodies… “it seemed to change.”

Everyone agreed that clarity was needed in the zoning code, yet the exact form of clarity sat somewhere beyond grasp. Other communities, said Mr. Muenzer, are “all over the map” in their treatment of decks.

In the end, the committee voted to hold the matter at the Planning and Development Committee for further deliberation. A list of the number of properties that would be thrown into noncompliance will inform such consideration.