An infrared camera can be a useful tool when performing an energy assessment.
Infrared thermography consists of a thorough visual inspection of building with an infrared camera. It essentially takes the guess-work out of pinpointing the drafts and the leaky spots within a property. It registers the exact temperature of various areas and provides the building owner with a precise visual representation of the imperfections in the building's thermal envelope.
If a picture is worth a thousand words, an infrared picture could very well be worth a thousand dollars, because it reveals the spots where your building is wasting energy (and money), and gives you clear directions for remediating them. Some of the imperfections in your building's thermal envelope will be obvious: around windows and doors, for example. But chances are, there will be some big surprises, too; and that's part of what makes infrared imaging so valuable - you might discover that the constant draft in the foyer or reception area could be taken care of with a simple bead of caulk along the baseboards.
One last thing to consider when scheduling an infrared assessment is that for best results, there needs to be a temperature differential (delta T) between indoors and outdoors. Recommendations as to precise numbers differ, but you should talk to your auditor about an ideal differential for your region, climate and building.