World's Tallest Modular Building Tops Out

May 16, 2016




The residential tower at 461 Dean Street, part of the Pacific Park project in Brooklyn, New York, was topped out at 32-stories with the last of 930 steel modules.

The modules are built at a factory near the Brooklyn Navy Yard that assembles four modules a day, which allows about one floor a week to be completed. The tower's floors range from 36 modules at the bottom to 20 at the top.

The factory has a series of building stations. The first station preps and cuts all the materials – drywall, piping, etc. – so that only assembly is required in the module bays. Each module is numbered according to a coded system – for example 2419 is the 19th module on the 24th floor – and all parts are put together into kits that are delivered to the module construction bay as the steel frame is brought in to help reduce construction time. The steel frames are one of the few items not built in the factory, but are shipped up from Virginia.

The next station builds the bathroom modules. As bathrooms are more detailed and, as a result, require longer to construct than the rest of the module, they are built as separate sub-components, which are then inserted into the main modules. The last prepped component for a module is the façade pieces, which are built offsite and then attached in the factory. These pieces are self-sealing to limit the amount of work on the construction site.

The final stations are the module construction bays, which take up half of the entire factory space. With 26 modules under construction at a time, there is roughly a full floor being built at a time. Once finished, the modules will be shipped at night to the site, where they are then attached to the current building. The only work that then needs to be done is finalizing any connection points, such as pipes, electrical, and doorways.

Developed solely by Forest City Ratner Companies, half of the apartments will be available for low-, moderate-, and middle-income New Yorkers and an affordable housing lottery for the tower's Fall opening is open now at