Asset vs. Operational
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What is an asset rating?
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.. figure:: ../images/pyramid.png
   :align: right

   **Figure 3. Home Energy Use Pyramid**

The Home Energy Score is an asset rating. An asset rating seeks to quantify the energy
efficiency of a building based solely upon the inherent components of the house. The
Scoring Tool captures data on insulation levels and the heating equipment efficiencies,
but does not take into account thermostat settings, appliances, or plug loads
because the energy used to operate these components can vary widely depending on
occupant behavior. The way the Scoring Tool defines "home assets" for Home Energy Score
is displayed in Figure 3.

An asset score allows homes to be compared an "apples to apples" basis because it compares houses to
one another based on their assets and not how occupants operate the houses. The Home Energy Scoring
Tool assesses the effect of changes in a home's assets, while the occupant-dependent factors and
behaviors are assumed to be somewhat constant.

What is an operational rating?
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

An operational rating normalizes the measured energy use of a building (e.g. energy bills) so that it can
be compared to the measured energy use of a similar building type, such as a single-family home,
school or office. Differences within building type, such as size, number of occupants, climate or hours of
operation, may be used to normalize the measured energy use to facilitate an equitable comparison.
Operational ratings can be used to prioritize a group of buildings for efficiency improvement based on
the poorest measured energy performance. Home Energy Score is not an operational rating, but can be
paired with operational assessments to further refine recommendations for each home.