REVISED: NPS Building Polygon Data Transfer Standard - Geometry

This data transfer standard describes a polygon structure for buildings. This data set includes both buildings that currently exist as well as sites of buildings that have been relocated or destroyed. Only features of a non-sensitive nature and freely available to the public are included (although the model has been designed to accommodate sensitive data in the future, if needed). Multiple feature polygons may coexist, including perimeter footprints, building envelopes, buffer areas and obscured polygons. Perimeter geometry is described as the total area upon which a building stands and is defined by the shape of the outer edge of the roof line. Envelope polygons are described as simple geometric rectangles that nominally enclose perimeter geometry. Buffer polygons are described as an area of defined distance that surrounds a structure. Obscured polygons are described as a polygon location that has been randomly shifted in order to obscure exact locations, while allowing display of approximate locations for mapping purposes. All buildings of interest to the National Park Service are included, including those not owned by the NPS but located within authorized park boundaries and facilities that are leased by the NPS and cooperators which are located outside park boundaries. Only structures with a roof, commonly enclosed by walls, and designed for storage, human occupancy, or shelter for animals are included. Other structures not designed for occupancy, such as fences or bridges, are excluded. Buildings include offices, warehouses, post offices, hospitals, prisons, schools, housing and storage units. Attribute data are intentionally limited to those necessary for spatial data maintenance and stewardship. Data from external database systems are intended to link with these data to provide basic feature attributes. The means to maintain unique identifiers for each building (BLDG_ID) as well as unique geometries associated with that feature (Geometry_ID) are linked through use of Globally Unique Identifiers (GUIDs). Information about the source and vintage of individual polygons is documented within the Edit_Date and Poly_Notes attributes.