A year after a St. Louis-based finance firm with $5 billion of assets under management bought a French-style chateau outside of Dallas on the Texas prairie, it has unveiled plans to begin work this month on a new high-end hotel and spa — as well as a design center — to help facilitate weddings at the venue.

Twain Financial Partners recently filed plans with the state that outline the construction timeline for its $40 million of improvements to the 44,232-square-foot mansion and the nearly 40 acres surrounding the property at 1851 Turbeville Road in Hickory Creek, Texas, which sits 31 miles north of downtown Dallas near Lake Lewisville.

Construction is expected to start this month, with completion scheduled on the 45,000-square-foot design center by the end of May 2024. The Olana Hotel and Spa, which includes villas and a pool building, is scheduled for completion by the end of September 2025.

The mansion, originally called Champ d'Or, was considered the largest residence in Texas when it was built in 1999. Telecom tycoon Alan Goldfield and his wife Shirley had the mansion custom-built to resemble the Vaux-le-Vicomte in Paris, but the $52 million mansion proved too costly to occupy, and it was later sold at a loss.

At the time of the acquisition of the property from a Denton, Texas-based limited liability company last year, Twain Financial Partners outlined plans to build a 110-room hotel at the property, which it touts on its website. Terms of the deal were undisclosed. The firm did not immediately return a media request from CoStar News. An affiliate of CoStar, Land.com helped market the property at $17.5 million last year.

For the past five years, the mansion has been used as a wedding venue by Walters Wedding Estates, which owns the Wildwood Inn in nearby Denton. The wedding company did not immediately respond to an interview request from CoStar News. The mansion is expected to continue to be utilized as a wedding venue, with the design center and hotel and spa supporting wedding parties and guests.

Before it was used as a wedding venue, the mansion had a bowling alley, hair salon, theater room, racquetball court, two elevators, wine room, ballroom, a two-story library and a conservatory, among many other upscale finishes and European-style designs.

Duncan & Miller Design of Dallas is the architect on the hotel and spa project as well as the design center, according to the state permit.