Spokane developer and hotelier Walt Worthy has filed environmental documents for his proposed 15-story convention center hotel project, and he says he hopes to begin construction within a month or two.

Worthy's Spokane Valley-based development company, Worthy Enterprises LLC, proposes a construction timeline starting this month and running through March 2016, according to environmental documents required for a project of such scope under the Washington State Environmental Policy Act.

Worthy says, however, he's not ready to begin construction yet, although he might announce a groundbreaking date yet this summer.

He says Worthy Enterprises is finalizing negotiations with subcontractors, and the project has met some obstacles including higher construction costs than he had anticipated.

In earlier predevelopment documents filed with the city of Spokane, Worthy had estimated the construction cost at $50 million.

"It's a challenge to build something like this at a price that room rates in Spokane can support," says Worthy, who's also working to land a national hotel chain.

Worthy and his wife, Karen, also own and operate The Davenport Hotel Collection, which includes the Davenport Hotel, the Davenport Hotel Tower, and the Hotel Lusso, which have a combined total of more than 600 guest rooms.

He says Craig Woodard, owner of Brick & Mortar Architecture & Development, of Spokane, is collaborating with Worthy Enterprises on the convention center hotel project design.

"We're working on plans and renderings," Worthy says.

The proposed hotel site is a full city block known as the South Block, which is bordered by Spokane Falls Boulevard, Main Avenue, and Bernard and Washington streets, just south of the INB Performing Arts Center.

The property currently is occupied by a public parking lot.

The SEPA documents describe the project as a 714-room hotel with 70,000 square feet of assembly space, a restaurant and lounge, a pool, and exercise area and an adjacent parking garage with 900 stalls.

In all, the project will provide more than 920 parking spaces, while eliminating the 330-space public parking lot, creating a net gain of roughly 600 parking spaces, the SEPA document says.

Worthy recently signed an updated letter of intent in which he agreed to buy the 2.75-acre property, contingent on a mutually agreed upon appraisal to determine the sales price. The Spokane Public Facilities District owns the property, having bought most of it in 2008 for $7 million. The PFD operates the Spokane Convention Center, the INB Performing Arts Center, and the Spokane Veterans Memorial Arena.

The agreement obligates Worthy to dedicate 300 of the new parking spaces for INB and Convention Center patrons. Under the agreement, the PFD will pay for a skywalk over Spokane Falls Boulevard that would link the Convention Center and the new hotel.

The project will offset impacts on city services by providing a "much needed tax base increase for the city, county, and state," the SEPA document says, adding that a total of around 500 employees would work in three shifts at the convention center hotel.