SYNTHETIC STUCCO & INSULATION SYSTEMS Whichever Product You Choose, Follow the Details To a Tee. by William Lotz A new system from Dryvit, called Exsulation, is installed over rigid fiberglass insulation rather than EPS. Another key difference from its peers: It's mechanically fastened, so it can go over virtually any substrate. Exterior insulation systems with expanded polystyrene (EPS) insulation and acrylic stucco were developed after World War II in Germany, and exported to this country in 1969. The systems are especially popular for retrofitting existing, uninsulated masonry buildings. They are also increasingly popular in southern climates for new residential and commercial construction. Many to Pick From Dozens of manufacturers are selling variations of the system. Some sell the components and instructions to anyone, and some sell only to approved, trained contractors.