The Hills-DeCaro House is most significant for its architecture which represents the transition and integration of Wright's early experimental style and his mature Prairie style.
 Among features which reference his earlier designs are the windows; instead of the elaborate, geometric art-glass patterns which Wright first introduced in the Frank W. Thomas House, Wright employs simpler leaded frames with clear glass.
 The design is most similar to that of the Robert G. Emmond House or the wood muntin configuration of the Thomas H. Gale House, two of Wright's first works.
 Additionally, the house has a finished basement and attic, both of which Wright would avoid whenever possible following the development of his Prairie house.

Elements which are purely Prairie in style include the extensive use of stucco contrasted with dark wood banding.
 Several later works, such as the Stephen M. B. Hunt House and Robert W. Evans House share similar detail work and employ the same rectangular frames at each corner.
 The horizontal emphasis created by this banding, as well as the deep overhangs and window groupings is also a hallmark of the Prairie style.
 The arrangement of rooms in the first floor of the Hills House and extended porches are evocative of the pinwheel shape found in the Ward W. Willits House, Darwin D. Martin House and other works.
 As Wright broke away from the conventional, rectangular floor plans with the development of his Prairie homes, the hidden entrance also became more common and can be found in nearly every one of his Prairie houses.

One component which epitomizes the transitional nature of the Hills-DeCaro House is the dual-pitched, Japanese inspired roof which recalls similar roof designs for the Harry C. Goodrich House and George W. Smith House, both completed ten years prior.
 However, the cantilevered eaves of the Hills-Decaro house are even deeper – stretching 5.5 feet (1.67 m) on the upper story – and the fascia is even thicker than those of its early predecessors.
 When paired with the unique, stepped shingle pattern, these adjustments further accentuate the Prairie style horizontality of the house.
The Hills-DeCaro House is most significant for its architecture which represents the transition and integration of Wright's early experimental style and his mature Prairie style.  Among features which reference his earlier designs are the windows; instead of the elaborate, geometric art-glass patterns which Wright first introduced in the Frank W. Thomas House, Wright employs simpler leaded frames with clear glass.  The design is most similar to that of the Robert G. Emmond House or the wood muntin configuration of the Thomas H. Gale House, two of Wright's first works.  Additionally, the house has a finished basement and attic, both of which Wright would avoid whenever possible following the development of his Prairie house.
Elements which are purely Prairie in style include the extensive use of stucco contrasted with dark wood banding.  Several later works, such as the Stephen M. B. Hunt House and Robert W. Evans House share similar detail work and employ the same rectangular frames at each corner.  The horizontal emphasis created by this banding, as well as the deep overhangs and window groupings is also a hallmark of the Prairie style.  The arrangement of rooms in the first floor of the Hills House and extended porches are evocative of the pinwheel shape found in the Ward W. Willits House, Darwin D. Martin House and other works.  As Wright broke away from the conventional, rectangular floor plans with the development of his Prairie homes, the hidden entrance also became more common and can be found in nearly every one of his Prairie houses.
One component which epitomizes the transitional nature of the Hills-DeCaro House is the dual-pitched, Japanese inspired roof which recalls similar roof designs for the Harry C. Goodrich House and George W. Smith House, both completed ten years prior.  However, the cantilevered eaves of the Hills-Decaro house are even deeper – stretching 5.5 feet (1.67 m) on the upper story – and the fascia is even thicker than those of its early predecessors.  When paired with the unique, stepped shingle pattern, these adjustments further accentuate the Prairie style horizontality of the house.
Edward R. Hills House