There is an incredible wealth of information on how to construct energy efficient, durable, and comfortable buildings. Sure, most of that information is totally disregarded when buildings are constructed. But it would be difficult to argue that houses in the US are constructed poorly because technicians don’t have access to good information. This wealth of information should be directly applied in the few hundred thousand new homes constructed each year.
On the other hand, there are roughly 125 million existing homes in the US. So modifying the stock of existing home is a much bigger deal, especially in terms of energy consumption and extending the lifespan of these homes. The approach to modifying existing homes is likely to be very different from building new. With few exceptions, (and deep energy retrofits are the exception and not the rule) most people will replace a small handful of building components at a time.
If we’re really lucky a sophisticated client (and hopefully all readers of this blog) will replace siding and windows simultaneously, thereby giving us the opportunity to add foam insulation to the outside of the building and install high-quality glazing. Many of our energy retrofit clients in New Jersey receive a water heater upgrade in conjunction with furnace, air-sealing, and insulation. But this approach is at least partly driven by high subsidies, and is not a trend we see outside the NJ Home Performance with Energy Star program.