Virtual energy audit can help energy service professionals quickly find the best targets, while it is not as detailed
as a traditional energy audit. On the other hand, to conduct an ASHRAE Level II detailed energy audit, plenty of
data need to be collected on site by auditors. Data of s ome existing residential buildings can be provided by owners
or designers, but may be incorrect due to building’s constant renovation, and insulation aging, and home owner’s
lack of technical knowledge. Among all the required data, collecting as -is building geometry and as-is thermal
resistance value of the envelope components is a labor-intensive, costly, and slow process. In addition, different
modelers inevitably create different simulation models even when they are modeling the same building using the
same modeling tool because modeling of thermal views of buildings and the corresponding definition of data needed
in the simulation is often arbitrary in practice