For a considerate amount of time I was tasked with assisting the effort to bring Seaside to art standard.  This involved receiving concept art, consulting Environment Artists, and using references to bring certain buildings from blockout to full art.  This consisted of a mix of purpose-built assets coming in from the art team as well as basic BSP Brushes in Radiant Black.  A majority of these buildings shown below are created from basic brush shapes and layers of textured terrain sheets.