The purpose of this guide is to provide useful examples of high performance retrofit techniques for the building enclosure of wood frame residential construction in a cold and somewhat wet climate. The examples demonstrate effective management of liquid water (rain and ground water), airflow, water vapor flow and heat flow. Retrofit ventilation approaches are reviewed because mechanical ventilation is taken to be a necessary component in high performance buildings. This guide does not address mechanical heating, cooling or water heating systems beyond outlining basic combustion safety measures.

Existing homes present an incredible variety of conditions. The variations of building techniques over time and across different regions combined with the inherent individuality among builders lends to a mind-boggling variety of configurations in existing housing stock. Rather than try to encompass all of the possible solutions responding to each of various existing conditions, this guide details a limited number of options for deep energy retrofit of common configurations found in wood framed New England homes. Through its experience in guiding high performance retrofit projects, BSC has found the solutions in this guide to be applicable to the vast majority of circumstances. Some retrofit projects will require solutions that are not described in this guide.

Successful retrofit is a challenging endeavor. Successful high performance retrofit poses further challenges. This guide is not intended as a comprehensive guide to all challenges, hazards and constraints that may be encountered in the course of high performance retrofit. Contractors implementing deep energy retrofit (DER) projects must be able to recognize structural conditions and hazards - such as, but not limited to hazardous materials, faulty electrical or plumbing systems - that pose a risk to the building or occupants. This guide does not provide guidance on techniques for remediation or assessment of structural, electrical or plumbing systems nor does it describe the appropriate remediation of hazardous materials.

Despite every effort to describe proven and robust techniques, the guide cannot replace sound judgment. Neither can the guide compensate for lack of training. Individuals performing services directed to deep energy retrofit will need to exercise good judgment and draw upon appropriate training in implementing measures described in this guide.