The Greystone Cellars building stands on a terraced hillside site on the west side of 29/128, about a mile north of St. Helena's central business district. It has , three stories, and a basement, and is around long, wide, and tall, with thick walls. As a wine cellar, it held 3.5 million gallons. The building was designed in the Richardson Romanesque style, with an arched entranceway and tower, stone mullions and transoms, a low sweeping roof, well-fitted stonework, and a large and simple stone façade. The building's exterior is made of local light gray volcanic stone put together with Portland cement; the trimmings are of a red stone. Bourne had insisted that gray stones were used in the east façade of the building (its main façade), with darker or other colored stones usable for the other sides of the building. The roof originally used black slate roof tiles.