In a city known for leading the pack, one new building is pushing what is possible by doing more with less.
Nestled in Boston's Financial District, Winthrop Center just became the world's largest passive office building in the world.
The Germany-based Passive House Institute certified the building for hitting energy-efficiency metrics.
"It is truly innovative," said Brad Mahoney, director of sustainability for Millennium Partners. "It is a simple approach, but it is innovative because it is forward-thinking."
Last month, Boston estimated buildings in the city account for 70% of its greenhouse gas emissions.
"Winthrop Center will use 65% less energy than a typical office building and 65% less carbon, so it is critically important," Mahoney said.
Mahoney estimates meeting the Passive House Institute's levels added $12-$15 million in construction costs — money that the building will recoup fast in lower energy costs.
In addition to the windows, which are three layers, the building has energy-efficient climate zones, and a plan to harness heat from workers and computers to cut down on utility use.
The building is on the site of a former massive parking garage.
"This is a new dawn. We need solutions like this, and it shows that it can be done on a very large scale," Mahoney said. "People that come into this building, work in this building, they have that agency to be part of a climate solution."