The 63 City Building, the nation’s second-tallest building, will undergo a five-year renovation including the replacement of its 13,400 gold-tinted windows, industry sources said Monday.

The 249-meter-high skyscraper in Yeouido, Seoul’s financial district, is currently home to more than 10,000 employees of Korea Life Insurance and other companies. The landmark building also houses a number of foreign companies operating in Korea.

The large-scale renovation, including the remodeling of vacant offices and upgrade of IT infrastructure, will continue until 2016.

The building’s status as the country’s tallest building has been usurped by new building projects such as the 284-meter-high Seoul International Finance Center, which opens this month in Yeouido.

“The 63 Building needs to be refurbished as its facilities have worn out over the past 30 years. When the work is completed, the building will transform into a new cutting-edge building,” said a Korea Life Insurance official.

Erected in 1985, the building houses company offices, an aquarium, an IMAX theater and an observatory. The surface color changes depending on the angle of sunlight.

The building receives 8,220 daily visitors, with the accumulated number surpassing 75 million as of this January.

By Lee Ji-yoon (jylee@heraldcorp.com)