Construction started this past week on a $13.5 million renovation of the Des Moines Marriott Downtown, a project hotel managers say will provide the city with a “gem” for downtown visitors.

“We want to be a leader in what Des Moines has to offer as far as hotel accommodations,” said Cindy Roberts, director of sales and marketing for the Marriott, which is the largest hotel in the state. Roberts expects the renovations to help not only the hotel, but also the city, better compete for large conventions.

The hotel, which turned 25 years old this year, will receive a complete overhaul over the next four years. The project will be carried out in two phases, the first of which will be completed this winter. The second phase of construction will begin in 2009. The first phase, estimated to cost about $7 million, will focus on the hotel’s six suites, all bathrooms and public areas. A majority of the work will be done between mid-December and early January 2007, when the hotel tends to be less busy.

According to Roberts, the 33-story property will look noticeably different when visitors step inside. The paneled glass in the entryway will be replaced with a single panel of glass, giving it a more open look. The dated window coverings will be removed, the large concrete pillars will be covered with wood or marble tiling and more seating areas will be added to fit the needs of today’s travelers.

“Today’s business traveler spends wants to work and socialize in the lobby,” Roberts said. “They want to have a place to sit with their laptops and have a glass of wine or a cup of coffee. They’re spending less and less time in their rooms.”

Also on the main level, the sundry shop adjacent to the front desk will be expanded to include a business center and Starbucks Coffee kiosk. The beauty salon will move to the main level, with the concierge lounge taking its former space on the mezzanine level overlooking the lobby.

Everything from lighting, carpeting and woodwork will be replaced in the hotel’s ballroom and meeting rooms. The fitness center will be expanded and rebuilt so the exercise equipment is separate from the pool area. The cardiovascular machines will each have flat-screen TVs on them, similar to what you’d find in a new health club.

One of the changes Jeff Hilt, the hotel’s area general manager, is most excited about is a new restaurant. Allie’s, the current restaurant, will be replaced by Rock River Grill and Tavern. The casual-dining restaurant will feature private high-back booths. Booths behind the bar area will each have their own LCD TVs.

“Allie’s was a concept based on 15-20 years ago,” Hilt said. “This brings a fresh, contemporary look to the space. It’s going to be a destination in itself.”

The second phase of renovation in 2009 will focus on installing new furnishings and carpeting in the hotel’s 409 guest rooms.

“Our hope is that this would provide a premier hotel in the city that everyone could be proud of as their lead convention property,” Hilt said.