Movie: in this exclusive interview, Rem Koolhaas tells Dezeen why the colossal new De Rotterdam tower is the most visible OMA skyscraper yet. "Nobody will be able to avoid" seeing it, he says.

Located on the south bank of Rotterdam's Maas river, De Rotterdam is a 150-metre structure where overlapping glazed towers accommodate apartments, offices and a hotel. It is only the fourth high-rise that OMA has completed, even though the firm has developed designs for dozens over the years.

"This is on a site where nobody will be able to avoid seeing the entire building," says Koolhaas, comparing the project with the Rothschild Bank Headquarters in London and CCTV Headquarters in Beijing, both of which are located within a dense cityscape. "It has a superb location on the river that can be only approached on one bridge, so we could really predict how it will be perceived," he said.

OMA originally looked at designing two buildings on separate plots. The architect explains that he wanted to avoid "planting needles" so instead came up with a concept for a single structure with large vertical openings that break up the overall mass.

"We made a building that consists of separate volumes that were slightly shifted vis-a-vis each other so that it was very adaptable," says Koolhaas. "We could easily replace one part with another part and therefore accommodate different logics and arguments."

"This shifting creates a large building, but a large building that is a very dynamic presence in the city, because it is very different from any angle. It can be a wall, it can be almost three separate buildings, it can be a single mass," he adds.

The building officially completed yesterday. Tenants including the municipality of Rotterdam are expected to move in over the next year.

Images of De Rotterdam are courtesy of the Netherlands Board of Tourism & Conventions.