– From a windy top-floor patio overlooking Lake Superior, Mark Lambert watches the final piece of his decadelong jigsaw puzzle fit into place.

Concrete rises from a leveled hillside as workers prep a third five-story apartment complex on a sliver of land now known as BlueStone.

This is the fun part, Lambert says.

By the time the 194-unit Vue at BlueStone opens next summer, the $50 million housing and retail complex alongside the University of Minnesota Duluth campus will wrap up just as Lambert envisioned it.

"It's a nice cap to the work we've done at BlueStone," said the owner of Stillwater-based Summit Management. "Every phase has gotten better."

The Vue will be marketed as luxury apartments, while the BlueStone Lofts house about 300 students and BlueStone Flats contains 142 generally market-rate apartments. With Tavern on the Hill as its centerpiece, the shops at BlueStone filled quickly and were, in pre-COVID times, consistently busy.

"I think I've been one of Duluth's best salespeople," Lambert said. "I've reached out to every possible retailer and user and said, 'Hey, come to Duluth, come to BlueStone.' "

Lambert made his weekly drive up to Duluth on a recent Thursday to check in on the project, and he said he was grateful the governor allowed construction to continue while so much of regular life was on hold.

"There's so much uncertainty right now, the ability to have a project that's tangible and physical — there's a lot of excitement for it," he said.

Adam Fulton, the city's deputy director of planning and economic development, said the project has "brought a new level of activity and vibrancy to an area of Woodland Avenue that was ready for reinvestment."

"The project has added hundreds of new housing units at a time when Duluth needs more housing options," he said. "It has also helped build a bridge between UMD and the Mount Royale neighborhood."

The city projects that it needs 3,800 more affordable housing units over the next decade, a prospect made difficult by the area's tricky terrain and largely built-out urban core, not to mention that the bulk of new housing being built contains largely high-end units.

"As a whole community — it doesn't matter which price point you're talking about — we are short housing," Lynn Nephew, a commissioner for Duluth's Housing and Redevelopment Authority, said last month. "But the one place we are lacking most is that lower-income stock."

Lambert said he's brought a variety of housing types to his development and added many smaller units to Vue to make rents there more "approachable."

BlueStone started, like so many things in this era of Duluth's development, with the school district's Red Plan that sold off many old schools.

In 2011, Lambert was one of the buyers. With city approval, the Woodland Middle School and surrounding 27 acres would make way for BlueStone.

"The early chatter was we were going to create a new Dinkytown," he said. "But frankly I think we did better than Dinkytown."

Lambert first started building in Duluth 24 years ago with the Campus Park complex and also put up Boulder Ridge and Summit Ridge apartments.

Walking across the dirt and concrete that will one day hold an underground parking garage, Lambert says he's focused on getting work done by July 2021. But then again, he said, "I'm always looking for more."