Bob Boesen paid a lot of money for the historic Butler Mansion last week — $2.9 million – but he figures it should be a good investment for a couple of reasons. “The historic significance is a big part of why I’m buying it,” he said. “The majority of the purchase price is based on income” from the lease arrangement with the only tenant, Integer Group, “but I was thinking that if the whole world falls apart, and Integer leaves Des Moines, it’s still a real, real signature property, and somebody would want to go into that kind of space.”

It’s special, all right. The one-time home of Earl Butler was named the building of the 1930-1939 decade when the Iowa chapter of the American Institute of Architects selected the state’s best buildings for its “A Century of Iowa Architecture” project.

Designed by Kraetsch & Kraetsch, it was described by the Iowa architects as “one of the finest Streamline Moderne houses in the country.” The flat-roofed home with striking curves has perched on a high spot at 2633 Fleur Drive since 1937. It has increased in size with a couple of additions.

“We totally renovated the house in 1987 and 1988,” said Liz Newell, who bought the place with Jack Kragie to serve as the headquarters of their Kragie/Newell advertising agency. “That renovation included 8,000 additional square feet. We did another addition in 1993, adding 12,000 square feet because of rather explosive growth for our company.”

Kragie/Newell merged with The Integer Group, a national company, in 1998. Integer has been weighing another building expansion for several months, and might add another 12,000 square feet.

“This building has been written up in more journals and venues than you can imagine,” said Newell. “The mansion was a calling card for us. People just were stunned when they would come to our place of business.”

Kragie and Newell now live in Chicago, and decided this year that it was time to sell the building to someone who would take care of it. “I’ve known Bob Boesen for many years, and he had expressed interest at one point,” Newell said. “We began discussions, which led to the sale.”

“I’m mostly an out-west kind of guy,” said Boesen, the owner of Waukee-based Boesen Homes Ltd. “Mostly what we do is residential development and some commercial buildings. The Butler Mansion has always been one of those properties you drive by and admire.”

Newell said Boesen is someone who can handle further development of the Butler site; Boesen said more additions are “possible and likely.”

Boesen hadn’t been in the mansion since the second addition was completed, and his wife had never visited the place. So when it was part of a recent holiday homes tour, the couple bought tickets and checked it out. They won’t have to buy tickets from now on.

As for Newell, she said owning the Butler Mansion was “one of the greatest experiences. It’s a wonderful asset, and people were always curious about it. It was a privilege to own it.”