This dataset consists of 2-dimensional roof outlines ("roofprints") for all buildings larger than 150 square feet, as interpreted by a contractor (Rolta) for the whole area of the Commonwealth using DigitalGlobe ortho images obtained in 2011 and 2012, supplemented with LiDAR (Light Detection And Ranging) data collected from 2002 to 2011 for the eastern half of the state.

The roofprints as delivered were enhanced by MassGIS using Normalized Digital Surface Models (NDSMs) derived from the same LiDAR data. Other layers were used, including the Level 3 Parcels, to aid in review, especially where LiDAR data were not available.

This feature class is being updated using ortho imagery captured in 2013, 2014 and 2015. The newer imagery allows MassGIS staff to remove, modify and add structures to keep up with more current ground conditions. Structures from the original compilation that are removed are stored in an "archive" feature class for edit tracking and historical purposes.

Last updated on 5/22/2017.

In ArcSDE the layer is named STRUCTURES_POLY.