Published in 2013 by Chelsea Green, The Greened House Effect: Renovating Your Home with a Deep Energy Retrofit, by Jeff Wilson, is a worthy read. Jeff Wilson is committed to doing what he can to conserve energy and safeguard our environment, and he does this through tackling his own home with a deep energy retrofit (DER). As a media professional focused on sustainable architecture and a former builder, he brings considerable knowledge to the topic. His detailed account of the experience is both instructive and entertaining.
The Wilson family had dreamed of building a new house in the countryside, abandoning their 70 year old house in Athens, Ohio. But then they realized that the more ecological thing to do was to stay put, drive less, and make their existing house more comfortable and energy efficient. They hired a professional energy consultant to perform a thorough energy audit of the old house, and he found many places to focus their attention on to get the best return on their investment.
While discussing the choices they made for their particular situation, Jeff covers practically all aspects of accomplishing a DER in general. His aim is to inform the reader of all of the options available for their personal situation. So while he describes the specifics of performing the renovation from the exterior of their house, he also explains how the same ends could be met through an interior retrofit.
The goal in all of this work is to greatly improve comfort and energy efficiency through adding insulation, sealing out air leaks, and reducing thermal bridging throughout the exterior envelope of the house. This includes foundations, floors, walls and roofs. The Wilsons managed to reduce the cost of the energy used in their house by 85% with the modifications they made, which included the replacement of some inefficient appliances.
While they were in the disruptive process of renovation, they decided that this would also be a good time to make a needed addition to their house, providing garage and office space. This led to completely changing the angle of part of their roof, and this made it possible to conveniently add solar electric panels on that roof. They mitigated the cost of the photovoltaic system through tax and renewable energy credits.
Jeff does mention how passive solar retrofitting can increase efficiency, bringing in sunlight to help heat your home, but he never explains why he opted not to do this in his own DER project. I would have preferred more emphasis on passive solar design, particularly given that a major home renovation can often benefit from this. Likewise, the role of thermal mass within the thermal envelope of the home is not adequately discussed. I feel that any house can be improved thermally with the strategic distribution of thermal mass, even when passive solar windows are not employed.
I appreciate the depth of detailed information provided in this book and recommend it to anyone considering taking on a home renovation project and would like to make their home more energy efficient.