State architect George Heins designed it for what was at the time the 29th Separate Company of the New York Army National Guard.

The surrounding properties are all residential, with the exception of a large former school building to the west on Catherine Street.

[2] The building itself is a two-story structure of Medina sandstone laid in a random ashlar pattern with a raised foundation.

It consists of two sections: the main administration building, facing south to Prospect Street, and an attached drill shed on the north.

The entrance itself is a recessed segmental-arched sally port with a pair of paneled oak doors below a tripartite transom.

Stepped gabled ends project from the hipped roof shingled in asphalt with standing seam metal.

[2] On the side elevations of the nine-bay drill shed is paired narrow flat-arched windows set off by buttresses.

The entrance hall has a large oak staircase, the company meeting room a tin ceiling.

The drill shed has exposed steel trusses, wainscoted ceilings, a balcony, and wooden floors.

[2] It was the first of seven extant armories designed by George Heins, who had replaced Isaac Perry as New York's state architect.

Like his predecessor, Heins used many features of medieval military architecture such as towers, crenelation, parapets, and sally ports, for an overall Gothic effect.

[2] In April 1917, the unit was deployed into World War I as part of the 27th Division, drawn entirely from the New York National Guard.