Powers' Urban Ventures LLC is adding 33 new units in its Fire Clay Lofts in the Upper Larimer neighborhood at 32nd and Blake streets.
The units are priced from $125,000 to $269,000.
The lowest-price units at Fire Clay and at Monarch Mills in the Central Platte Valley project must meet income requirements based on the area median income.
The affordable units also have restrictions on the deeds, capping appreciation.
At Monarch Mills, 56 of the 69 units are considered affordable.
The 13 market-rate units in the eight-story building at 15th and Delgany streets will be priced from $275,000 to about $375,000.
Powers said that the below-market units at Mills will be available for buyers earning between $50,000 and $75,000 annually, depending on the size of their households.
"I like to call it moderately priced, because the Central Platte Valley, by definition, is a high-priced market," Powers said. "Basically, we are building the most affordable housing for the valley."
Monarch Mills is being designed by Denver-based Studio Completiva and will be built by Palace Construction.
David Zucker, of competitor Buchanan Yonushewski Group, an architectural, development and construction firm, praised Urban Development's efforts.
"Downtown should not be just for the rich and famous," Zucker said.
The city's requirement for affordable housing is similar to, but predates, the inclusionary housing ordinance approved by the Denver City Council.
"That's an agreement that goes back to 1997," said Anne Warhover, president of the Downtown Partnership. "East West Partners (developer of the luxury Riverfront neighborhood in the valley) worked out a deal with the city that is basically a swap," Warhover said.
Under the deal, East West will sell the land to Denver-based Continuum Partners, which, in turn, will sell it to Urban Ventures, Powers said.
"East West, Continuum and Susan are all known for their creativity," Warhover said.
Monarch Mills shares a site with Continuum Partners and the future home of the Museum of Contemporary Art/Denver. The museum is expected to cost about $3 million and be as large as 20,000 square feet.