Architectural and development firm Flank is making an old sort of history in South Williamsburg.

The company announced on Monday that it has broken ground on what it says are the first two new timber buildings to be constructed in New York in over a century at 320 and 360 Wythe St. The three-story 320 Wythe is scheduled to be completed in the spring, and the five-story 360 Wythe is due by the end of 2018. Flank confirmed to Bisnow that it is the owner, architect and builder of the properties.

New York building regulations limit the height of timber buildings at six stories, and Flank will be filling its low-rise buildings with 57K SF of office space and 22K SF of retail. 360 Wythe will carry the bulk of that, with 46K SF of office above 18K SF of retail, with below-ground parking and a residential component on the top two floors.

320 Wythe will have 11K SF of office space above 4K SF of retail, and both buildings will have rooftop terraces. The structures will have brick exteriors and wooden interiors, including exposed wood structures. The wood will be in the form of mass timber, a form of wood engineered to be heavier and able to support more weight. Flank has enlisted Nordic Structures to provide the timber, made of black spruce from sustainable forests in Canada.

Flank co-founder Mick Walsdorf hopes the two buildings will usher in a new era of timber construction, more sustainable due to wood absorbing more carbon dioxide than it emits. Although the buildings are designed to fit the aesthetics of nearby turn-of-the-century industrial buildings, they will have modern technological and HVAC systems.

Howard Hersch and Michael Berg of JLL will handle office leasing for the buildings, while an RKF team of Alex Beard, Eddie Mamiye and Pierce Thompson will market the retail spaces. Leasing is open for both buildings.