Renters will soon be able to live in one of downtown St. Paul's most iconic buildings.

Madison Equities plans to convert some of the offices in the First National Bank Building, known for its glowing "1st" sign, into 170 apartments, said Jim Crockarell, head of Madison Equities.

Construction on the $42 million project is scheduled to start in the last quarter of this year with completion expected in 2020.

The complex is made up of three towers. The apartments will be located in the 16-story East tower, located on the corner of 4th and Robert streets. Office tenants have been gradually moved from the East tower to the building's North and West towers.

"There's strong demand for apartments in St. Paul," Crockarell said.

About 177,000 square feet of space in the East tower, which was built in 1915 and was originally known as the Merchants Bank Building, will be converted.

Tushie Montgomery Architects is designing the renovation. MP Johnson is handling the construction.

Madison Equities, which purchased the First National Bank Building in 2015, spent about $500,000 in 2016 to replace the neon lights in the "1st" sign with energy-efficient LED lighting. Madison Equities, which owns more than a dozen properties in downtown St. Paul, is also working on converting some of the office space in the Park Square Court building near Mears Park into a boutique hotel.

St. Paul has seen a resurgence of empty offices remade into residences in recent years such as the Sibley Square at Mears Park office building which reopened last year as the 333 on the Park apartments. Office occupancy rates dipped in 2017 in downtown St. Paul to 79.2 percent.