Here is an intro from their web site:
America’s existing housing needs help. Many of the 130 million homes in this country were constructed before modern energy and building codes were established. These homes often suffer from performance problems ranging from inflated energy consumption to poor thermal comfort to indoor air quality issues.
The Building Performance Institute, Inc. (BPI) is the nation's premier standards development and credentialing organization for residential energy efficiency retrofit work. We are helping build an industry, create a workforce, and support programs through professional certification, contractor accreditation, and quality assurance services
There are dozens of these professionals in the St. Louis area and more are being trained as I write. The group pictured below is in the process of a a 2 week multi-certification program. The candidates bring experience to the program from wide variety of related fields including heating and cooling, construction and weatherization programs.
They will be trained to use the latest diagnostic equipment, including a blower door (pictured below), among others that will provide real metrics for understanding and correcting issues around the house the decrease comfort and increase bills.
A big issue in the world of business is summed up with this: "You can't manage what you can't measure." You can get the measurements you need to make informed decisions about home improvement and energy efficiency concerns. Do it. For all the right reasons.
Google: home energy audit in st. louis and get a quote or 2, make a decision, and get to work.