Alexandria Real Estate Equities, Inc. has started site preparation at its new headquarters building in Pasadena.

Located at 380 E. Union Street, the five-story building will feature 82,000 square feet of office space atop an underground parking garage. The approximately 30,700-square-foot project site was previously a parking lot.

Global architecture firm Gensler is designing the low-rise structure, which will abut the building that currently houses ARE's offices. The design has been described by Pasadena Heritage as "hyper contemporary." A conceptual massing shows a low-rise structure with amorphous, offset floor plates.

Rios Clementi Hale Studios is the project's landscape architect.

The new office building joins a number of multifamily residential developments that have recently taken shape north of Colorado Boulevard.

ARE specializes in biotech real estate developments across the country.