5 
12 *The Angi rating for Energy Efficiency Auditing companies in O Fallon, IL is a rating based on verified reviews from our community of homeowners who have used these pros to meet their Energy Efficiency Auditing needs.
*The HomeAdvisor rating for Energy Efficiency Auditing companies in O Fallon, IL is a rating based on verified reviews from our community of homeowners who have used these pros to meet their Energy Efficiency Auditing needs.
Last update on July 30, 2026
Serving O Fallon, IL and surrounding areas
In business since 2001
Free estimates
Credit card accepted
"St. Louis Insulation did a great job. Zac and his team were great to work with and they cleaned up after their work was completed. We were very happy with the project results and highly recommend St. Louis Insulation."
+40
Serving O Fallon, IL and surrounding areas
In business since 1978
"Paul Peterson is a knowledgeable and friendly guy.? Arrived at my house 15 min. prior to apt time.? Paul reviewed the areas I thought were the worst, and showed me leaks in the house I would never have thought of.? I was not surprised at the outcome of the energy audit, but I was surprised by the price.? It was less than I thought it would've been."
Serving O Fallon, IL and surrounding areas
In business since 2022
Free estimates
Credit card accepted
"They are in the process of sending out an engineer"
+3
Serving O Fallon, IL and surrounding areas
In business since 1971
Emergency services offered
Credit card accepted
"Our water heater went out the other night. I called and explained what was going on and they assured me that someone will be out as soon as possible. A bit later the technician came to the house ,first he greeted us then he put on his shoe covers before coming into the house. When I showed the technician the problem he was very patient in explaining to me what all needed to be done and he answered all my questions in a way that i could understand. I was impressed with his knowledge of the business but more impressed with his people skills. That night was our first time to call a plumber and if we ever need one again we will definitely call them!"
Serving O Fallon, IL and surrounding areas
In business since 2009
Free estimates
DelVon Hardaway is the professional you are looking for when a home or business energy analysis is required. More and more this is becoming a valuable tool across the country. Everyone needs a current energy audit, so do not hesitate to call DelVon Hardaway for your energy savings analysis.
Serving O Fallon, IL and surrounding areas
In business since 1990
Emergency services offered
Credit card accepted
"Excellent. Eddie Givens, the owner of the company, personally fixed our AC unit. All of his HVAC technicians were working today. Eddie offers a wealth of services. We plan to next use him for an electrical project and replacing our current HVAC contractor with twice annual check ups. We strongly recommend Eddie Givens"
From average costs to expert advice, get all the answers you need to get your job done.
Discover the average home energy audit cost, what impacts pricing, and how to save money on your audit. Get transparent, expert-backed cost info for homeowners.
Get a detailed breakdown of thermal imaging home inspection costs, including average prices, cost factors, and tips to help homeowners budget.
Discover the energy-efficient window costs. Learn about installation prices, cost factors, and tips to save money on your window upgrade.
Wondering what an energy audit is and how it can help keep you safe? Keep reading to learn about home energy audits and how they can save you money.
A home energy audit is a detailed write-up of how to lower your utility bills and increase your comfort level. Find out if they’re worth the cost.
Thinking about scheduling a home energy audit? Learn how to improve energy efficiency, lower your utility bills, and hire the right local pro for the job.
