Community Solution : Housing

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Buildings consume more than 50 percent of our nation’s energy, about 40 percent to operate and 10 percent to build, maintain, and eventually dismantle (the latter is often overlooked and is not shown on the following chart). They are major consumers of energy, even more than transportation. In addition they have a long life – 50 to 100 years or longer. Homes use a little more than half of the total energy used for all buildings, or 22 percent of total U.S. energy. There are more than 115 million households in the U.S. and new housing construction typically runs between 1 and 2 million residences yearly.

Since the late 1990s, there have been three standards for energy performance beyond the basic building code requirements set by the International Energy Conservation Code (IECC); these are EnergyStar, LEED, and Building America. The first two standards have set energy goal savings in the 15-25 percent range. Building America has a higher range (30-60 percent), but has built relatively few homes. Two other new standards have recently been defined, one by the National Association of Home Builders (NAHB) called the ICC-700-2008 National Green Building Standard, and the other from Germany, called Passivhaus (referred to as Passive House in this country).

The German Passive House standard sets a much higher energy savings goal than the other four. Passive Houses use ultra-thick insulation and highly efficient doors and windows, with an airtight building envelope to avoid heat loss through leaks. A Passive House uses so much less energy than a home built to conventional standards that little or no “active” central heating and/or cooling system is needed.

Because of global climate change, we need to dramatically reduce CO2 emissions by 80-90 percent before 2050. The building industry in the U.S. is now beginning to be aware of the seriousness of the CO2 problem and the need for deep energy cuts in buildings. However, the Green Building movement has so far had minimal effect on reducing building’s energy consumption. While some tens of thousands of so called “green” or energy-efficient buildings are now being constructed each year, this is a small number when compared to the conventional new homes being built. After ten years EnergyStar has certified only about 1 million of the more than 100 million existing homes.
Solution: Legislate 90% Energy Efficency in the Nation’s Building Codes

LEED certification program for commercial buildings has made only marginal progress and its parent organization, the US Green Building Council, has acknowledged that its position on energy consumption has not been a strong one. A new much higher performance standard is needed. National building codes for energy performance need to be legislated by the state and federal governments. These codes should meet the standards of 80% to 90% heating and cooling energy reductions of the German Passive House, the feasibility of which has been demonstrated in over 20,000 buildings in northern Europe over the last decade. A high standard will encourage innovation from builders and manufactures, as has been shown in Europe, which now has many super efficient products which are not available in the U.S. – yet.
Solutions: Retrofit the Millions of Existing Homes

Since homes last so long, it is important to deal with energy consumption in existing homes, not just in new homes. This is particularly true at a time when, due to the nation’s financial crisis, new building starts are at a very low point. For these reasons our main focus is on retrofitting the existing housing stock.

Home retrofitting should focus on making those changes with the greatest energy savings and least cost, such as finding and fixing air leaks, providing window coverings and/or replacements, eliminating phantom electrical loads, and installing ultra-low-energy appliances. Changes should be based upon an assessment of the individual house through the use of tools like blower door tests and infrared cameras. Part of the process of reducing energy use in buildings also includes increasing insulation in the building envelope (walls, ceilings and floor) and air-sealing the building. Only after heating loads have been reduced, ideally by 70 to 80 percent, will it then be time to consider replacing or eliminating the heating system and adding alternative energy sources.

Reducing energy use will conserve scarce resources, an important priority in the post-Peak Oil world, and reduce greenhouse gas emissions.