Georgetown's residential architecture can be described as conservative in its orientation. There is very little of the architecture of theatrical display or of violent contrast with the work of the past. While the architectural developments in Georgetown follow leading contemporary trends in the United States, they frequently do not appear until one to three decades later. The delayed adoption of contemporary architectural styles naturally screens out excesses and tends to the normative middle course. Contributing to the continuity in residential architecture is the dominance of the builder-architect rather than the designer architect. Control of the middle and upper-middle class architecture by the constructor accounts in part for the similarities in style.