"In the sub-basement, we have a 4,000-square-foot live music venue and a lower-level bank vault lounge and then a first-floor restaurant," he said. "We have some historic, really cool hotel suites that will be on the third floor overlooking Cass Park, and a rooftop pool."

If built as currently conceived, it would join a raft of new hotels planned and under construction in and around downtown, including the Shinola Hotel, the Siren Hotel in the former Wurlitzer Building and the Element Detroit at the Metropolitan Building. Also planned are a 28-story second tower for the Crowne Plaza Downtown Detroit Riverfront and a West Elm hotel in Midtown.

Gretchen Valade, whose grandfather Hamilton Carhartt founded the eponymous Dearborn-based workwear brand Carhartt Inc. in 1889; Moisides, executive member of Detroit-based 400 Monroe Associates LLC; and David Sutherland, partner with the Wakefield, Sutherland & Lubera PLC law firm in Grosse Pointe Farms, are the members of the 640 Temple development group.

Construction is expected to begin in the spring or summer and take up to 20 months to complete, according to the brownfield plan.

When Crain's last reported on the project in December 2016, it was expected to cost north of $20 million. However, the brownfield plan says it's now an approximately $65 million project. The complexity of the restoration, including the replacement of hundreds of windows, caused the large development cost increase, Moisides said.

Chemical Bank provided the construction loan on the project.

Birmingham-based McIntosh Poris Associates is the project architect, while Grand Rapids-based Rockford Construction has the general contractor. Both companies have Detroit offices.

In addition to $5.7 million in brownfield incentives, the developers anticipate Obsolete Property Rehabilitation Act and historic tax incentives.

The Wayne County Commission approved the building sale in April.