The coastal regions of South Carolina contain a rich diversity of vibrant ecosystems that provide invaluable services such as, producing oxygen, absorbing carbon dioxide, filtering water, purifying air, and providing wildlife habitat just to name a few. Sadly, many coastal ecosystems including; salt marsh, isolated wetlands, and upland forests, are at risk due to poorly planned land development. A more sustainable approach to urbanization having less impact on ecosystems is necessary to accommodate predicted increases in human population and preserve biodiversity and quality of life standards. Fortunately, South Carolina is home to a number of progressive planned developments, yet some questions remain regarding their levels of actual sustainability. Six planned communities in coastal regions of Charleston and Beaufort counties were analyzed for their levels of sustainable effectiveness. A set of sustainable land development principles that address environmental integrity, economic vitality, and social equity were applied to the case study sites. Findings revealed that few of these planned communities are optimally addressing all of the ten principles of sustainability, however, most of the principles were addressed to some degree.