A DER or Deep Energy Retrofit is not about reaching a certain number, using specific products, replacing an item, or slapping a band aid on an issue, but rather it implies a comprehensive inspection being done, a plan being developed, with the culmination of opening &/or accessing the areas needed to properly fix the energy related issues buried deep like insulation, ducts, etc… In order to qualify as a DER, the house should also be brought up to meet or exceed current energy codes (HERS Rating of 85 or less for 2009 code or a 70 for 2012). For More: Deep Energy Retrofits – a primer
