Welcome to the Deep Energy Retrofit (DER) website.

We created this site to help inform the public about the Deep Energy Retrofit process, and by doing so, stimulate future DER projects. A deep energy retrofit (DER) is a process of rebuilding the exterior of a structure using building science, in order to reduce energy consumption and improve the comfort and value of the home.  Old houses were built to be leaky, often on purpose do to construction limitations, specifically related to moisture and the materials and building science of the time. However, building science has advanced tremendously in the last two decades and we now know how to make homes that are high performance.  A high performance home provides great indoor environmental quality, improved livability, improved durability, and consume about 30% of the energy of a typically built home.

Existing housing is not efficient, with up to seventy percent of the energy it produces being wasted. Many houses are uncomfortable and expensive to heat and cool and the most cost effective time to do DER work is now. Interest rates are low and energy prices are high and getting higher. The following is just one example of how beneficial a Deep Energy Retro Fit can be for the owner of an older home.

 Rhinebeck Project

As you can see from the pictures below, this Rhinebeck home was in dire need of an external upgrade. Many of the windows were more than 100 years old, and the house was so leaky that in the winter snow could often be found on the floor after a storm. The complete report can be found here. 

The owners of this Rhinebeck Home report that the improved comfort and air quality are probably the most important values of their DER.  They also installed a geothermal HVAC system, which the 70% reduction in heating loads made economically possible.  Over time the reduction in energy consumption more than pays for the DER, but again, the most significant benefit is the improved livability of a high performance home.

Rhinebeck NY House prior to DER

The Rhinebeck Home with the DER complete