Save for the tasteful white slipcovered outdoor furniture, the courtyards and gardens of Van and Marsha Miller's French Quarter home seem much as they could have nearly 200 years ago.

The 3,573-square-foot house at 8631 Daytonia Ave. has a unique entrance: it’s separated from the street by an enclosed courtyard that sits behind a black exterior wall.

So getting the design right, Mr. Sottile said, is “incredibly important.” The front entrance is also a place where a few inexpensive changes can boost a home’s overall value.