A multifamily and retail project Brooklyn, New York, has employed the use of ground-glass pozzolans in their concrete mixes.

The new complex covers 789,000 sq ft, with Lendlease replacing 40% of the foundation's concrete with ground-glass pozzolan.

Lendlease states that when the project is completed, it will become the State’s greatest residential build using a geothermal system.

This mix lowers the embodied carbon of concrete, and utilises waste from municipal glass recycling programs.

The company also states that the addition of ground-glass is less permeable than cement made with slag or fly ash.

“We know that there’s a lot of glass available because, unfortunately, the U.S. is not fantastic about recycling glass through municipal recycling,” said Amanda Kaminsky, director of sustainable construction for Lendlease’s Americas portfolio.

When finished, Lendlease claims 1 Java Street will be fully electric and become New York state’s largest geothermal residential building, reducing annual carbon emissions from heating, and cooling by 53% compared with typical residential systems.

The project is expected to be open in late 2025, and will include 834 apartments, 13,000 sq ft of retail, 27,000 sq ft of amenities, 276 parking spaces, a waterfront esplanade, and a host of sustainable features.