Once a trendsetting 1960s suburban office park, today Edina’s Pentagon Park is a dated cluster of 15 deteriorating buildings, most recently known for foreclosure and failed renewal plans.

But redevelopment is on the horizon, and not just any redevelopment. Enthusiastic city officials say the proposed revitalization of the 43-acre site with hotel, office and retail space, and perhaps housing, could top $500 million — more than the Downtown East project tied to the new Vikings stadium.

“It’s huge,” said Edina City Manager Scott Neal. “This is the biggest project we’ve done since Centennial Lakes. … Once this starts and attracts the class of tenants we think it will attract, other developers will see that and want to build on that.”

Developer Scott Tankenoff cautions that redevelopment will occur in phases and will take years. But the site on West 77th Street that he describes as “broken and dysfunctional” also has a prime location north of Interstate 494 between Hwy. 100 and France Avenue in a city that recently pledged $54 million in tax reimbursements for public improvements — if the developer delivers.

“The city really did step forward and demonstrate to us that Edina is serious about making this site work, getting jobs, increasing the tax base and most importantly, removing blight,” said Tankenoff, managing partner with Hillcrest Development. “I want something commensurate with Centennial Lakes and Normandale Lake [office park] in quality.”

Pentagon Park opened in 1968 as one of the first suburban office parks in the area. It was successful for several decades but hit the skids in the last 15 years, said Bill Neuendorf, Edina’s economic development manager. Ownership changed, a major development proposal fell through when the recession hit and the property went into foreclosure.

Hillcrest began buying parts of the property in 2010 and completed acquisition early this year. The firm also renovated five office buildings at one end of the land and is renting space.

At the other end of Pentagon Park, demolition is expected to begin later this year to clear the site for a hotel, offices, and medical and perhaps retail space. While plans for the entire 43 acres aren’t final, Hillcrest has told the city it wants to create 1.4 million square feet of office space, 40,000 square feet of retail, a 400-room hotel, shared parking structures and possibly housing.

It’s an unusual project in Edina, where redevelopment plots tend to be small.

“To get 43 acres in a fully developed city like Edina is a rare opportunity to reinvent and re-imagine an area,” said Neuendorf. “This is probably the largest redevelopment opportunity in this city for this generation.”

The City Council’s move last month to grant the project tax-increment financing set up a city-developer partnership. Hillcrest could be reimbursed up to $54 million on property taxes from its new buildings as compensation for constructing public improvements like streets, sidewalks, trees, shared parking ramps and soil stabilization.

Tankenoff said his challenge is to revamp Pentagon Park to be “modern for today and relevant for tomorrow.” One issue is how to connect the concrete and asphalt office park to what is now Fred Richards Golf Course, across 77th Street. The golf course will close at season’s end and the city plans to convert it to a park.

Tankenoff said that while the upgraded 77th Street will still be a truck route, wider sidewalks and boulevards will be added so people can safely walk or bike. The Nine Mile Creek Regional Trail is expected to run through the park or along the road across the street, and ways to connect to that amenity will be explored.

Tankenoff’s goal is to build a development that feels like Centennial Lakes or Normandale Lake, an office park in Bloomington. He said both feature quality architecture and “a public-private fabric where you don’t know where private ends and public begins. They’re great places.”

He expects to incorporate features like locked indoor storage and shower rooms to encourage bike commuting. Surface parking will be minimized, and parking ramps could include shared public-private space.

Because the City Council and Planning Commission pushed for a development that is more than a 9-to-5 office park, Tankenoff agreed to consider adding housing. It all depends on economic conditions as Pentagon Park is redeveloped, he said.

“I want to make the city happy; I believe there should be housing there,” he said. “Housing is really hot now in Edina, but what if it’s not a couple of years from now? We do not want to overpromise and not deliver.”

He said he hopes to clear land for the first phase of the project later this year.

“We want to show progress and change, but it takes time to get everything pieced together,” he said. “We’re extremely motivated and focused to move as quickly as we can, but … this could take 10 or 15 years.”

He said he wants the new Pentagon Park to be a signature project. “I could do this for 100 years and never have another project like this.”