Speckled red granite columns. Brass trimmed railings. Everything about the lobby of Fifth Street Towers screams 1980s.

Now, the almost-twin tower complex in downtown Minneapolis is about to embark on a multimillion-dollar renovation, its largest makeover, in hopes of shedding that 30-year-old look. Construction is set to begin as soon as this month with completion expected next year.

"In order to help companies attract and retain top talent, we need to do everything we can to be the place that everyone wants to go to work," said Erin Wendorf, vice president of office leasing for Transwestern, who is recruiting tenants to Fifth Street.

The towers currently have a 70 percent occupancy rate. And one of its long-term tenants, the law firm Stinson Leonard Street LLP, which has been there nearly since it opened, recently decided to move to the Fifty South Sixth building next year.

"We recognize in our challenge of reletting significant vacancy that we have an opportunity to reset Fifth Street Towers and change the entire narrative," said Bob Six, chief operating officer of owner Zeller Realty Group, in a statement.

The renovations are an attempt to appeal to a broader tenant pool than just accounting and law firms, including creatives, tech workers and others, Wendorf said.

"Progressive companies in all industries are embracing their office space as a chance to strengthen branding and recruit top talent," she said.

Amazon.com Inc. announced in June it had opened a technology development office at Fifth Street. Several advertising agencies, including Team Arrow Partners, a media planning group whose main client is Target Corp., have moved into the buildings in the past year. Last November, ad shop Martin Williams moved into Fifth Street to be under the same roof as its sister company BBDO Minneapolis. Both firms are owned by New York-based holding company Omnicom Group.

"It wouldn't have been our first choice because the building had vacancy and it was a little dated looking. Because we are in advertising, we take these things like design seriously," said Tom Moudry, president and chief creative officer of Martin Williams.

However, after moving from the RBC Plaza into its new offices at Fifth Street, Moudry said he and his colleagues now enjoy the Fifth Street buildings' proximity to light rail and food trucks.

Moudry said any improvements to the common spaces would be beneficial to his office of more than 100 creative workers. "A huge recruiting aspect of any agency is not only the space but the building and the neighborhood," he said.

The towers were built in 1984 and 1988 and stand 25 and 36 stories tall. A $2 million renovation in 2013 freshened the space and helped raise the occupancy from 64 to 73 percent. Last year, a company associated with California-based PIMCO investment firm bought Atlanta-based Invesco Real Estate's share of the buildings for $154 million. Zeller Realty Group remains a partial owner.

Zeller hired Shea Design and ESG Architects, both of Minneapolis, and the Chicago office of Perkins and Will to lead the new remodeling effort.

The skyway level lobby, designers say, will be transformed to give it the feel of a boutique hotel. Some of the walls that close off parts of the floor will be taken down. Many will be wrapped by panels of wood with light strips.

Skyways are no longer just seen as conduits to get people from building to building, said David Shea, founder of Shea Design.

"We want people to actually go down there and meet down there," Shea said.

Another large change for tenants will be to have all the buildings' amenities centralized onto one floor instead of scattered like they are now. In the makeover, all of the amenities will be relocated to the ninth floor — complete with a refurbished fitness center, new conference center and a clubhouse lounge with a rooftop deck. The current fitness center will be converted into a bike hub with bike parking, a repair shop and locker rooms with showers dedicated to cyclists.

Zeller is also considering a Super Floor connection between the two towers on floors three to eight to allow tenants around a 45,000-square-foot footprint with dramatic two-story atriums. A decision as to whether the Super Floor design will happen will be made by the end of August.

The first elements of the renovation are expected to be completed in October with the majority of the project done by next March. If the Super Floor concept is chosen, it would be completed by next summer.

Zeller hired Wendorf and Reed Christianson of Transwestern to spearhead leasing at Fifth Street as well as Chicago-based real estate consultant the Telos Group LLC to provide strategic services. The same team was involved in the recent redevelopment effort of Washington Square. After interior renovations, that complex has become a technology hub, attracting tenants such as Code42 and JAMF Software. In the past 18 months, the Telos-Transwestern team has leased more than 350,000 square feet of vacant space at Washington Square.

Nicole Norfleet • 612-673-4495

Twitter: @nicolenorfleet