This 16 page PDF Building energy optimization. The most cost effective energy efficient house would not use current solar photovoltaic power
About 4.9% of the oil used in the United States is used to heat homes (mostly in the northeast). Adopting optimum cost effective energy efficiency can lower the cost of home ownership while saving oil and natural gas.
The combination of the building choices list above would be the most cost effective way to achieve high energy efficiency
the energy efficiency breakdown is charted above
There are large gains in heating and cooling
Initial energy efficiency gains reduce the monthly costs for a home. 50% energy efficiency can be cost neutral and 44% energy efficiency is near the maximum cost reduction.
Transitioning from oil plan
Thermoelectric technology for a lot of energy efficiency 2010+
Energy supplies in the USA
The Dept of Energy, has a section Energy Efficiency and renewable energy which is developing a lot of energy efficiency technology for buildings, commercial buildings, heating and cooling and lighting and vehicles. There are several technology roadmaps for more energy effiency.
The above chart breaks down the energy usage by major categories. The residential and commercial combine for a total building energy usage of 38%.
Industrial energy efficiency is another major area
Vehicle Energy efficiency technologies are another major area
Consider performing an energy audit of your home
Answers about home heating. Portable heating versus central heating cutoff points etc...