Like other regional architects such as Virginia Beach's Lewis Rightmier, Richmond's E. Tucker Carlton and Alexandria's Charles M. Goodman, McCullough took the open plans, striking geometry and low profiles of houses by Frank Lloyd Wright and built houses with regional elements appropriate to Virginia's climate and history. McCullough's trademark features includes terrazzo floors and raised fireplaces with levitating hearths.
Like other architects who designed in a regional style, such as Lewis Rightmier in Virginia Beach, E. Tucker Carlton in Richmond, and Charles M. Goodman in Alexandria, McCullough utilized the open designs, striking geometries, and low profiles of Frank Lloyd Wright's houses to create homes with appropriate regional elements for Virginia's climate and history. One distinctive feature of McCullough's work was terrazzo floors and raised fireplaces with hearths that seemed to float.