Overwhelming demand for things like apartments, office and retail space, plus improvements to the original design of the arena, Olympia says.

"We are out in the marketplace and we are reacting to this incredible feedback," Steve Marquardt, vice president of Olympia Development, the real estate company owned by Mike and Marian Ilitch, said in an interview with Crain's last week.

The District Detroit is ambitious and daunting: 50 city blocks, the majority of which were remarkable mostly for their barrenness, wedged between the freshly blooming downtown and Midtown areas, teeming with recent development and business activity.

At its heart is a hockey and event arena rising now at the corner of Woodward and Henry Street. Ancillary development is planned in dozens of individual projects spread across the 50 largely Ilitch-owned blocks, which will bring hundreds of thousands of square feet of office and retail space, plus about 1,000 multifamily units, to the market in the next several years.The arena's steel skeleton and concrete guts are rising above a 40-foot hole dug into the ground for the lower bowl and ice rink. A pair of office and retail buildings flanking its southern and eastern side, expected to bring a mixture of local and national tenants such as restaurants, bars and shops, also are under way.

"The plan appears to be very progressive and should contribute to Woodward and the surrounding streets' walkability and urbanism," said Robert Gibbs, managing principal of Birmingham-based"Unusually skillfully planned for such a large area."

Olympia said about $30 million has been spent just on infrastructure surrounding the arena.

Across Henry Street, another office building is in the works. This one, 40,000 to 50,000 square feet for multiple office users with first-floor retail space, is known as Building C.

To the west, about 132 multifamily units — 108 apartments (buildings D and E) and 24 townhomes — wrap around the nearly 1,200-space, six-story main parking deck for the arena, according to a request for proposal from developers.

That RFP, which focuses specifically on those two projects and was obtained by Crain's last week, spells out 19 separate sites throughout the district where multifamily construction and redevelopments are possible.

Among those possible projects (see map below): 300 units along Woodward in the so-called "superblock;" another 75 in the former United Artists Building on Bagley Street; 100 in the historic Eddystone Hotel that will be renovated; an undetermined number on a 1-acre patch of Brush Park land owned by; and an additional 250,000 square feet billed only as "student housing" next to the planned Mike Ilitch School of Business for

The superblock has long been talked about at the corner of Woodward and Montcalm in an area that is now surface parking lots just west of. The land is currently owned by St. John's Episcopal Church.

The United Artists Building is planned for about 75 multifamily units, the RFP says. According to a source, the redevelopment is expected to include first-floor retail space and a repurposing of at least some of the theater inside the 223,000-square-foot building, which was constructed in 1935 and has been owned by the Ilitches since 1997.

It has not yet been determined how the theater would be reused, if at all, said Richard Heapes, co-founder and partner of White Plains, N.Y.-based, the planning consultant on the project.

The 250,000 square feet of multifamily space identified as "student housing" near the business school is not incorporated into the official plan for the new WSU building, said Steven Townsend, director of marketing and communications for the business school.

Smaller planned projects — 15 units here, 25 units there, another 30 units there — are peppered along Second Avenue, Cass Avenue, Park Avenue and Temple Street, among others.

There are still plenty of unknowns, however.

Multiple sites spelled out in the RFP for multifamily development contain no information about the number of units they are expected to accommodate.

All told, the RFP's 19 sites total about 1.44 million square feet of building space, plus the acre of Brush Park land. The 675 units identified sit in about 958,000 square feet, or about 1,419 square feet per planned unit. At that rate, the 1.44 million square feet would accommodate about 1,015 units — right around how many units Olympia executives say are expected as part of the district project at this time.

Even though there are 19 sites identified in the RFP, responses to which were due Friday, Olympia remains cautious about how many projects would actually materialize. Doug Kuiper, vice president of corporate communications for, parent company of Olympia Development, said at least 10 residential projects are expected.