A significant portion of the Charles Ennis house is dedicated to the massive concrete block retaining walls that support the building on the steeply-pitched hillside. Other concrete block houses designed by Frank Lloyd Wright, constructed in the same region and around the same time, exhibit a more typical scale in line with his approach to residential architecture. Wright referred to this as "human scale," intending to reduce the traditional unnecessary heights to a level that suits the occupants. However, the Ennis house deviates from this rule: its rooms have high ceilings, which results in the concrete block mass rising above the window lines.

In terms of the floor plan, the house essentially consists of two bedrooms, with a guest room located adjacent to the dining room. The bedrooms for the original owners are separated from each other and connected by a long enclosed gallery and an open terrace. The dining room, kitchen, and guest room are situated on a raised level above the living room. This residence is one of the last designed by Frank Lloyd Wright to feature stained glass and one of the first, alongside the nearby Freeman house, to incorporate mitred glass windows. The design's monumental nature is somewhat softened and made more human by the scale of the concrete blocks and the combination of plain and patterned blocks.

Pfeiffer, Bruce Brooks, Frank Lloyd Wright, 1867-1959: Building for Democracy, Taschen, 2004