Detroit (AP)  -- A key piece in the redevelopment of Detroit's east riverfront is getting a makeover to increase its attractiveness to buyers.

The number of units at the 2.2-acre Watermark is being trimmed from 112 to 98, but the square footage of the upscale homes and condos will be increased closer to the size of luxury homes outside of downtown.

Developer Dave Bing said the project has to draw in about 30 more buyers before banks release construction money. But he said the effort — part of about $1 billion planned in public and private investment to revitalize Detroit's downtown waterfront — is a go despite the grim economy.

"As we got a lot of people coming down looking at the model, I think moving from a 3,000- or 4,000-square-foot home to a 1,600- to 1,800-square-foot condo was a little shock to some of the people," Bing, a businessman and professional basketball Hall of Famer, told The Associated Press.

Almost immediately after Watermark was announced last year, its two penthouses were sold for more than $1 million each.

The redesign reduced the number of units on the top floor of the nine-story tower from 14 to 10, but added up to 1,000 more square feet to some of the homes, said Bing, whose Springarn Development is leading the project.

The eight marina homes with direct access to the Detroit River have been increased to about 3,000 square feet each. Two of those units are about 4,000 square feet each. Their price tags still eclipse the $1 million mark and two already have been sold.

Bing, founder and chair of the Bing Group in Detroit, said there was no buyer interest in the six "city homes" to be built along Atwater Street, so they were scrapped.

"I think people who wanted to be on the water, wanted to be on the water, not necessarily on the street," he said. "We didn't want the city homes in the beginning, but part of the proposal that the city had us do was to make this into a village where you had three kinds of lifestyles, but that one lifestyle wasn't kind of received very well."

The redesign also reduced the overall cost to a little less than $60 million. It had been pegged at about $63 million before the changes.

So far, 28 units have been sold, with between five to seven more under negotiation, Bing said.

But between 55 and 60 need to be sold before banks will release $43 million in funding to begin and complete construction.

The Detroit Economic Development Corp. gave the development a $700,000 loan earlier this year.

"All our efforts, right now, are getting the units sold," Bing said. "Then we'll be back with the banks with something to talk about. Because we have not reached the threshold of the percentage of purchase agreement, there is nothing to go back and talk to the banks about."

Other riverfront development plans include Tri-Centennial State Park and the Detroit Riverwalk, a string of parks and public walkways along the Detroit River shoreline stretching from the Ambassador Bridge to Belle Isle park.

Struggling national and local economies, and a mortgage crisis that has hit the Detroit area as hard as anyplace in the country, have combined to make banks leery.

"The market, that's national, not just Detroit," Bing said last week. "We didn't see it coming. In hindsight, if we knew anything about it, we would have delayed it until things changed and became a little stronger or better. Once again, the market is not going to stay where it is forever."