New renderings show Minnesota United’s future stadium in the St. Paul Midway will be even less boxy and lower than previous depictions, but a firm start date for major construction remains up in the air.

Against the wintry backdrop of an empty bus lot, Minnesota United team owner Bill McGuire joined St. Paul Mayor Chris Coleman and Major League Soccer Commissioner Don Garber on Monday in turning dirt in a raised flower bed — a ceremonial commencement to a $150 million stadium construction project that may not officially break ground until late spring, at the earliest.

McGuire, stadium architects Populous and Mortenson Construction released nearly completed renderings for the future stadium, which will be built on the former Metro Transit bus barn property off Snelling and University avenues.

While most of the facility will rest on public land, its northern edges are expected to jut into the Midway Shopping Center, replacing an existing Rainbow Foods supermarket.

The two privately owned acres remain under negotiation between Eden Prairie-based SuperValu, which operates the Rainbow location on a lease, and strip mall owner RK Midway of New York. The particulars have delayed stadium construction once expected to start as early as last May or June.

Officials called the real estate issues typical of a complicated land deal involving multiple tenants and landowners.

“That’s something that the landowner deals with and works on,” said McGuire. “That will all get resolved at some point.”

Asked if he had considered reorienting the stadium from north-south to east-west to avoid the grocery store building, McGuire said, “We’ve looked at a number of options. Obviously, that’s not preferred.”

McGuire said Xcel Energy has been on site for the past three weeks, removing utility poles and relocating electrical lines to run underground.

Ken Sorensen, a senior vice president with Mortenson Construction, said his company is still finalizing schedules and budgets for major construction, though the $150 million estimated cost is “holding well,” and meetings with key potential subcontractors are about to start.

Without control over the Rainbow site, there are still some unknowns.

“We’re working closely with the team so we can sequence the work, so we can work with the real estate situation,” Sorensen said.

He expects construction will begin next spring in the future stadium’s southern section, where the bus storage facility once stood, and move north toward the Midway Shopping Center.

The work could be completed in time for Minnesota United to play in the new stadium in 2019, but it’s unlikely the stadium would be ready much earlier.

“It’s going to be at least a year and a half,” he said. “We would say a year and a half would be appropriate, but … we’re still preliminary with that. We don’t know.”

The team will play its 2017 and 2018 seasons at the University of Minnesota’s TCF Bank Stadium.

The new renderings include a few changes from earlier designs. The stadium has been lowered an additional 4 feet, reducing or eliminating the need for upward steps to enter the facility, and the field will be sunk 18 feet into the ground. The peak of the canopy will reach 78 feet above existing ground level, about two-thirds of the height of the Xcel Energy Center in downtown St. Paul.

“The idea is to not let it overwhelm,” McGuire said.

A fact sheet released at the media briefing describes a total capacity of 19,916 fans, with built-in expansion room allowing a future capacity of 24,474 fans. The stadium will have 25 suites, 38 semi-private seats known as loge boxes, and four club rooms. It will be 660 feet long at its longest point, and occupy 346,000 square feet of built space.

While the bowl-shaped stadium will not be capped, 84 percent of seats will sit under a partial roof covering. To allow natural light onto the grass, the latest renderings trim the roof so it does not extend over the field, but seating and roofing have been extended further away from the playing surface.

The overhang has “been expanded in the back, trimmed a little in the front,” McGuire said.

The facility will be wrapped with a synthetic mesh known as PTFE, and embedded with LED lights allowing for a change of color based on events, seasons or time of day. McGuire noted that after the musician Prince died, fans posted images to the Internet of the soccer stadium bathed in purple, the late singer’s signature color.

The stadium will be privately funded by Minnesota United and its investors and conveyed to the city.

Even so, critics have taken issue with more than $18 million in public funds that the city will devote toward infrastructure such as street approaches and sewer connections.

Mayoral candidate Tom Goldstein, a Hamline-Midway resident and stadium opponent, shared a written statement at Monday’s media briefing calling for more “human scale” amenities in St. Paul, such as improvements to the city’s after-school programming, Parks and Rec centers and Business Resource Center.

St. Paul Mayor Chris Coleman called the stadium a major improvement for the blighted land, and a boost for St. Paul.

“I can’t think of a more appropriate place to have Major League Soccer than in this community, with all of its great diversity,” Coleman said.