In this workshop, there was a consensus that EIA has the database, and from available data, energy intensity, e.g. energy used per household, can be calculated.
Energy efficiency is an interesting and useful concept for analyzing energy use.
Energy-efficiency loss occurs when more energy inputs are required to produce the same or reduced products or services. In reality, however, efficiency is difficult to measure. Because energy needs to be assessed relative to the amount of product or service provided, energy use rates, commonly called energy intensities, are the measures ordinarily used to assess efficiency trends. Energy intensities not only measure energy efficiency but also measures changes in other entities such as changes in weather and household income. However, the advantage of considering individual energy intensities is that you may easily measure and track them over time.