We used a local company named GreenQuest home solutions. They came in and did a free inspection of multiple points in our home. They discovered unsealed doors and windows, cracked forced air heat in our crawl space and no insulation below our floors. They repaired and updated our system to operate more efficiently. We would recomend GreenQuest to anyone that has questions about their homes utility use and health. The HomeHealth checkup was great!
While Actera does a good job with analysis, they are not general contractors like GreenQuest.

The benefit to a having a non-contractor do your audit should be obvious -- they've got no financial incentive driving their recommendations.