A proposal to redesign a block of buildings in Portland’s Old Port envisions a multistory marketplace spread over two buildings connected by a skywalk above the cobblestones of Wharf Street.

Now mostly home to bars and restaurants, the six buildings on Fore and Wharf streets would gain additional floors for housing, offices or hotel rooms, nearly doubling their current 50,000 square feet of space.

The makeover of the block would bring more dramatic change and some modern architecture to a section of the red brick-dominated Old Port recently elevated by the construction of the new Hyatt Place hotel.

The developer has yet to submit any formal plans or applications with the city, and details have not yet been released.

The owner of the buildings, Dream Port 3 LLC, announced this week that it had selected the concept by Archetype Architects principal David Lloyd as the winner of a design competition among three Portland firms that also included PDT Architects and Canal 5 Studio.

Dream Port, the investment and development arm of New Jersey-based U.S. Real Estate Advisors, Inc., bought the buildings for $5.6 million in an online auction last fall. They had been foreclosed on in 2011.

Lloyd said he had yet to discuss a time frame for the project with Dream Port managing director Steve Wolgin, who did not respond Thursday to a request for comment. But “it’s going to take a number of years to complete,” Lloyd said.

Lloyd had run estimates of the project cost, but said it would be up to Wolgin to divulge them.

Before selecting a winner, Dream Port presented the three proposals to the city’s historic preservation and planning staff.

Deb Andrews, historic preservation manager, said there were “no obvious red flags” that could trigger objections and stall the project. But she viewed the current plans as conceptual and said she expects there will be adjustments to the design as the project goes through the city planning process.

The block is part of a historic district. Andrews said there are buildings within the block that are classified as contributing to the overall character of the Old Port and should be preserved, and there are other buildings that can be torn down.

In the conceptual design, a building on the corner of Wharf and Union streets – the current home of Buck’s Naked BBQ – and two buildings adjacent to each other on Fore Street that house Fore Play Sports Pub and Pearl Lounge would be replaced with new, taller structures.

Buck’s Naked owner Wendy Caisse hasn’t seen the design, which depicts the marketplace where her restaurant is now. But she said she has a good working relationship with Wolgin and expects that he’ll continue to keep her informed of his plans.

“If the building can be renovated aesthetically and serve a better purpose, so be it,” she said.

The buildings that are part of the block are at 432, 434, 436 and 446 Fore St. and 42 and 50 Wharf St.

Wolgin told the Press Herald last month that the buildings have not been renovated in 200 years and are in need of an upgrade that he hopes will bring new energy to the area.

“We want the tenants to be mixed and diverse. We don’t want it to be just a place for kids to go and drink from 10 p.m. to 1 a.m.,” he said. “We want it to be a 12-months-a-year type of scenario where people welcome the shopping along with fine food and dancing and music, and all those things.”