3100 Clarendon Boulevard was a challenging renovation project in a partially occupied office and retail building in downtown Arlington, Virginia. Numerous curbs were installed on the edge of the building to accommodate a new façade. In the interior, new concrete beams were added on multiple floors to support the slab edge where shafts were added in the existing floor system. In addition to the curb and beam modifications, an area of structural topping slab on insulation was installed to raise the existing floor to create more usable interior floor space.