The appointed body that approves building designs in Charlottesville’s historic districts got a progress report Monday on the latest step in the development of a multimillion upgrade of West Main Street.

“We’ve thought a lot about design but we don’t have a specific design plan yet,” said Elliot Rhodeside at a special meeting of the Board of Architectural Review.

The city hired his firm, Alexandria-based Rhodeside & Harwell, in 2013 to conduct a study of the corridor and has rehired them to develop schematics for a concept approved by City Council in March.

The approved concept for West Main includes new sidewalks, bike lanes, tree plantings and the undergrounding of overheard utility lines.

The preliminary cost estimate to implement the streetscape is about $30 million, though that number could change as the construction documents are finalized.

Council has set aside $10 million for the project in the five-year capital improvement project and is applying for $18.3 million in funding through the Virginia Department of Transportation’s Smart Scale process.

“An important part of that plan is to update the estimate so that one knows what the real costs will be,” Rhodeside said.

Since March, Rhodeside’s team has been studying the Downtown Mall, which was designed by renowned landscape architect Lawrence Halprin and built beginning in 1976.

However, Rhodeside said the streetscape project is not intended to duplicate the mall.

“West Main Street should not be a replica of the Downtown Mall, but we believe it should have something of the spirit of the Downtown Mall,” Rhodeside said.

Much of the discussion Monday dealt with trees. Paul Josey, a landscape architect who serves on the city’s Tree Commission, has been hired to update an inventory of existing trees.

The current idea is to use strategic placement of trees referred to as “bosques” to help create different identities for different blocks of West Main Street. Rhodeside said Halprin used this technique on the Downtown Mall.

“So where there are no trees, there may be opportunities to play or to dine out, and where there are trees, there may be opportunities for quiet spaces to sit,” Rhodeside said.

Gateway sections such as at the Drewary Brown Bridge and at Jefferson Park Avenue would feature bosques with taller trees. Other areas designated for activities would have lower trees.

There would be no new street trees outside the First Baptist Church in order to ensure its architecture remains prominent along the street.

“We know that trees are very important to the community,” said Ron Sessoms, of Rhodeside & Harwell, but he added most of the existing trees are of the same zelkova species. “That is pretty much a monoculture of trees, and that makes existing trees susceptible to disease.”

However, using the new tree inventory, Sessoms estimates that at least 23 out of 89 existing trees in the right-of-way will remain.

“The corridor will be changing quite considerably as we relocate the curb lines,” Sessoms said. “There will obviously be a loss of trees, but there may be an opportunity to save trees throughout the corridor.”

Recently planted trees outside the right-of-way such as those in front of the Flats at West Village will remain, as they are on private property.

Other aspects of the plan also were discussed. For instance, all of the crosswalks that do not cross West Main Street would be raised at the same level of the sidewalks.

“The goal is to have the sidewalk be continuous,” Rhodeside said.

Other subcontractors also have been hired to assist with the work.

The architectural firm Bushman Dreyfus has studied three sites for a 200-to-300 vehicle parking garage.

Nelson Nygaard will conduct a traffic analysis to ensure whether reconfigurations of key intersections are feasible. The plan shows the slip lane leading from eastbound West Main Street to southbound Ridge Street — at the Lewis & Clark statue — as being eliminated in favor of a public plaza.

The Timmons Group began survey work in July of both above-ground and underground conditions. A major factor in the final cost estimate will be the price to place utility lines underground.

“We met with Dominion Virginia Power, who is really going to drive the ship in terms of identifying the undergrounding of infrastructure,” said Brian Copeland with the Timmons Group.

“Dominion’s position is that the city will be 100-percent responsible for the costs,” he added.

“You talk about the history of the neighborhoods, but I don’t see it reflected in the design,” said BAR member Laura Knott. “There are lots of place-making opportunities I don’t see expressed yet.”

“We agree,” Rhodeside said. “That’s sort of the next step.”

The schematic documents will be formally presented to City Council at the end of January, but Rhodeside said all councilors have seen parts of the plan in progress.

After this phase, Rhodeside & Harwell will be paid to develop “design documents” followed by final construction documents that will allow the city to place the project out to bid. Those documents will not be available until the spring of 2018.

The cost so far for the city for the initial study and the “design schematics” is $1.37 million.