The owners of the Glenstone Museum in the United States, Mitchell and Emily Rales, have announced the beginning of construction for a new building to house their extensive private art collection.

The museum will join an existing one on their private estate in Potomac, Maryland. The current building, which opened to the public in 2006, was designed by Charles Gwathmey of Gwathmey Siegel & Associates Architects and covers a total area of 23,000 sq ft (2,136 sq m).

By comparison, the new building will cover a much larger area at 150,000 sq ft (13 935sq m) and was designed by Thomas Phifer and partners.

According to the architects the new building will at first appear as a cluster of simple masonry forms, varying in size and embedded on a rise in the land. Upon reaching the building, the visitor will descend to gallery level and find a series of pavilion rooms, all of which will face inward toward a courtyard.

Landscaping was provided by PWP Landscape Architecture and will include integrated walking paths, bridges and restored meadows and woodlands. More than 6,000 trees will be planted from 40 native species.

The new edition to the museum is expected to be complete by 2016.