In the District Data Sheets attached to this nomination, vernacular houses have been described by their floor plan; stylistic designations have been used only for those buildings that possess individual decorative details derived directly from high-style architecture at the time of their installation.   Numerous timber-frame buildings have undergone alteration by the removal and replacement of their original chimneys; in these cases such buildings have been described by their apparent original plan (if exterior evidence exists) or merely as timber-frame vernacular if their original plan is unclear due to later alterations.


Since most buildings in the District do not have identified historic names, this category on the Data Sheets has been left blank in the cases of buildings constructed as free-standing single-family houses; other unnamed buildings have been identified by building type, specifically, double house, row house, apartment house, commercial block, school building and fire house.


The contributing status of structures has been assigned based on the retention of pre-1930 designs.   Buildings, which clearly major identifiable elements of their original (pre-1930) designs, have been designated as contributing [C].    Structures which appear to pre-date 1930 and which are similar in scale and materials to their neighbors, but which have undergone major alterations such that their period of origin cannot be readily determined, have been designated as minor contributing structures [MC].    Finally, those structures built after 1930 have been designated as intrusions [INT]; included in this last category are a number of buildings which may be re-considered as contributing structures once they achieve the age of fifty years.     Yards and vacant lots when they are separate parcels without buildings have not been designated as either contributing properties or intrusions.    Typical intrusions include gas stations, modern suburban houses and modern school buildings; most intrusions are of same scale, materials and use as contributing buildings, but are less than fifty years old.