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The Challenge of Existing Homes:
Retrofitting for Dramatic Energy Savings
This summary is a shortened, condensed version of the Full Article.
Executive Summary
Buildings can play a large part in reducing carbon dioxide emissions to mitigate the effects of global climate change. Much of the focus has been on reducing the energy use of new buildings by 50% or more, as called for by the 2030 Challenge, an effort championed by the organization Architecture 2030. The 2030 Challenge also calls for the renovation of existing building stock equal in square footage to that of newly constructed buildings and achieving the same 50% reduction in fossil fuel use. Achieving this goal with residential buildings would require leading-edge energy retrofits on about 1.5 million existing homes per year—many times the current rate of, at most, a few thousand homes a year.
Achieving a two- to three-fold reduction in energy use in an average existing home is not a simple or inexpensive task and it is best approached simultaneously with other renovations, such as siding replacement. Building owners can reduce energy demand in the house, which can involve adding high levels of insulation to wall cavities and the exterior of the house, air-sealing the house, replacing windows with high-performance models, and replacing mechanical equipment with energy-efficient models. Owners can also install renewable energy systems such as solar-thermal heating systems, photovoltaic power systems, and solar water-heating systems to meet remaining loads.
This article explores the scale of the challenge of retrofitting existing housing as well as specific strategies for lowering energy usage, and how best to approach those strategies in heating and cooling climates. Three case studies—in Massachusetts, New Jersey, and Texas—offer examples, and a checklist offers practical guidance.
DISCUSSIONSReader-contributed comments related to The Challenge of Existing Homes: Retrofitting for Dramatic Energy Savings - EBN: 16:7. Comments are listed with newest at the top.
The article quotes 0.2% as the turnover rate for existing residential buildings. This implies a 500 year time span for replacing them all, or say 250 average lifetime. Are you (and the EPA) really saying residences will last that long?
This is a good article on a difficult subject but I can't read the checklist!
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You're right--the replacement rate is pretty tiny. We derived that number from the number of tear-downs in the country each year, and I was pretty surprised that it was so small. To answer your question, a house life of 250 years isn't entirely unheard of, at least in the Northeast, where there are some houses still standing from the 1700s. But it's not typical. My guess is that the amount of new construction and major renovations far outweighs the actual tear-down-and-replace rate right now. That might change, if demand for housing increases in places where there is no available land. Then we might see the tear-down rate increase.