Home energy audits in Ontario give you access to government grants for anything from a Tankless Water heater to home insulation. Below is a brief synopsis of the steps a homeowner should take to when getting an energy audit.
Find a government certified service organization that is licensed to provide an energy evaluation where you live.

Book your D-Audit. This is the first audit and it takes the longest (2-3 hrs)
Preform all renovations and upgrades you are planning on doing.
Finalize by getting the E-Audit completed. This proves to the government that the changes you claimed to have completed are actually done.
Receive your grant money for the upgrades done.
Thats about it, you get a more efficient home and the Federal and Provincial governments will help you pay for it, not a bad deal.