The B.M. Allen House is a brick I-house of transitional Greek Revival/Italianate style, with Gothic Revival elements. The front door, lighted with a tall transom, is surrounded with a crossette architrave. The three-bay front porch sports a parapet pierced with pointed arches. A two-story ell abuts the north end of the main block; along its south face is a recessed double gallery, now enclosed. Six frame outbuildings, including two barns, enhance the property's significance.
The Allen farm is beautifully situated in the valley of Gunpowder Creek, with sweeping views in every direction. Riddles Run Road, a narrow rural road winding along the ridge, offers the traveler one of the finest vistas in the county and is a designated Kentucky Scenic Byway.
The House was added to the National Register in 1989.