That's assuming that you have access to exterior walls, otherwise, it's significantly more difficult to figure out what's going on.  ASHRAE has lots of publications on energy and conservation, but I've not run across anything specifically discussing energy audits.

Given the variations of materials and emissivities, it can still be quite tricky.  I'd assume that you'd be able to get gross indications of energy loss, but determination energy flux variations of less than 30% are probably the best that one could do, unless one had lots of moey for calibration and characterization of materials, paints, etc.

TTFN

Contact me at toadsack@arkansas.net for further contacts.  What you are looking for is taught by some ir training groups and there are guidelines available through at least one.  Also, a friend was responsible for the structural energy auditing program (using level I thermography)for Arkansas.  I will talk to him to see if he would mind sharing with you.  He is now retired.

I currently use Infrared Thermography to do Energy Audits on Commercial buildings.  Provided I understand what you are looking for I will give it a go.  I generally scan the exterior and interior of the building gathering good qualative images that tell the story.  You should have a delta T of at least 20 deg F.  I have 16 + years in commercial building construction and inspection so the things i see make sense to me.  I take Emissivity into consideration but I do not measure it.  My value given to the service is determined in btu/h loss through conduction and convection. btu/h loss = delta T x Area x U value.  I can give you a lot more info but it will be a long winded conversation if you are interested.

Yes, training is essential. But, as you can see, I am biased! Experience is also critical to getting good results as is defining the task. Without the framework of a procedure, most building inspections are less than useful or, perhaps, dangerously misleading. This is especially true at we hear more and more about mold growth and moisture in buildings!

With regard to standards, there are two main standards that can be used for frame buildings:
1. ASTM C-1060: Standard practice for Thermographic Inspection of insulation Installations in Envelope Cavities of Frame Buildings
2. ISO 6781 Thermal insulation, qualitative detection of thermal irregularities in building envelopes, Infrared Method

A further related standard is:
ASTM C-1046 Standard practice for in-situ measurement of heat flux and temperature on building envelope components

For concrete buildings the American Concrete Institute (ACI) Design Standard 530 incorporates an excellent procedure that include infrared testing.

A great deal has been published with regard to building inspections over the years. I suggest you turn to either the Proceedings of Thermosense, published by SPIE (www.spie.org) or Thermal Solutions (www.thermal-solutions.org).

If I can be of further assistance, please feel free to contact me.
Thermally yours,
John Snell
jsnell@snellinfrared.com
http://www.snellinfrared.com
http://www.thermal-solutions.org