The push to transform the Piraeus Tower into Greece’s greenest building shows what’s at stake in the EU’s decarbonization effort.

On the waterfront of the Greek port of Piraeus, a crane prepares to lift giant aluminum panels onto the shell of a 22-story tower. On an outdoor terrace, workers pour concrete in a gentle slope to steer rainwater into underground tanks. Inside, two men in hard hats plug strips of steel wool into an interior wall as insulation.

The €100 million ($103.5 million) renovation aims to turn the hulking Piraeus Tower, which has dominated the city’s skyline since the 1970s, into Greece’s greenest building. The facade will be covered with sun-deflecting fins, the thermal windows are made from recycled glass, each basement parking spot has an EV charging point, and sensors will measure the microclimate to help maintain green spaces. “The port was an ugly industrial area, derelict and dead,” says Olga Itsiou, chief operating officer of Dimand SA, the tower’s developer. “Our renovation will bring life back to the neighborhood.”