
Serving Derby, CT and surrounding areas
Approved
In business since 2007
Free estimates
Customers say: Quick response
"Did a great job. Prompt, efficient asbestos removal from my basement. Very courteous and professional. Would definitely recommend."

*The Angi rating for Energy Efficiency Auditing companies in Derby, CT 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 Derby, CT 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 September 01, 2026

Serving Derby, CT and surrounding areas
Approved
In business since 2007
Free estimates
Customers say: Quick response
"Did a great job. Prompt, efficient asbestos removal from my basement. Very courteous and professional. Would definitely recommend."

Serving Derby, CT and surrounding areas
Approved
Emergency services offered
Small jobs welcome
Credit card accepted
I conduct energy audit tests for homes, whether they are colonial or brand new construction. I can recommend you various forms of weathersealant, thermal wrappings, and storm window techniques, saving you thousands in the form of long-term heat insulation tech-forward solutions.
Serving Derby, CT and surrounding areas
Approved
In business since 2021
Free estimates
We pride our company on reliability, great communication, integrity, and quality work. We believe in giving our absolute best in all of our projects, no matter how big or small. You will find us to be competitively priced, with close attention to the details of each and every project. We are experts in our trade and will always keep you educated on your particular task or project. We look forward to earning your business, so please ask us for references. \n

Serving Derby, CT and surrounding areas
In business since 1935
Emergency services offered
Credit card accepted
"Everybody at the company is excellent! Especially Anthony, who did the audit. He was very courteous, knowledgeable, and professional."




Serving Derby, CT and surrounding areas
In business since 2006
Free estimates
Credit card accepted
"We have had NECS to our home several times for different projects: energy audit, attic insulation, and wall insulation. These are very professional, considerate, and honest people to do such work in your home. Our house is much more energy efficient after all we have done. Insulation pays for itself very quickly, and NECS took care of all incentive programs for us. You won't go wrong with them."



Serving Derby, CT and surrounding areas
In business since 2009
Emergency services offered
"I could not be more pleased with this company or this service. I found them here on AL and with a rebate, it was a great deal. When I called, the woman who answered was extremely polite and helpful and took the time to go over the entire audit process with me (she wasn't rushed as some receptionists are). They sent an email to confirm the date and time.
When the team arrived, they were on time and each of them introduced themselves by name to me before coming into my house. They were all very polite and courteous. The leader (I can't remember his name) gave me an overview of the process and explained things as they went. Basically, they simulate high winds around the house and then monitor for where leaks are. My house is relatively new and has no basement, so it was already pretty efficient, but there were some major leaks by the front door and attic door, which they sealed on the spot. They also showed me that I could hold my hand over any electrical socket, even ones on interior walls, and feel the "wind"--which means air was leaking out those! So I plugged them all with those little socket protectors. The guys also took me into the attic and showed me some leaks, and fixed them--and fixed the attic door by adding a little latch to help it stay closed. All in all, they reduced the amount of air getting into my house by 500 (I forget the units). It was clear they didn't just make up this number--they showed me the number after the first test and then after the second test (when they had treated the problem areas).
I also got a few free CFLs and LEDs, and bought 3 more LEDs since they were at a great price. They left some rebates with me, although all my appliances are new so I didn't need anything.
When they left, they each said goodbye and were very professional until the end. They were respectful in my home and asked before opening any closets or doors, etc. I felt very safe with them here, which is not always the case when people are in your home working. I think the price is a fantastic one, especially with the AL rebate that was on when I scheduled. I feel I got my money's worth. My husband and I had tried to plug some leaks ourselves, but we didn't really know what we were doing and we had no way to measure if we were really helping anything. This audit gave me hard numbers to look at and I was impressed that they did the fixes on-site (included in the price--for instance, they plugged a whole around my front door frame by installing a clear plastic barrier). It was a great deal and a great experience. Highly recommend!
Bonus--when we resell this house in a few years, I will definitely list that we got a professional energy audit performed on it and that it's very efficient. Definitely a selling point!
"





+38

Serving Derby, CT and surrounding areas
In business since 1992
Free estimates
Emergency services offered
"I rated them B for responsiveness because the first time I called I was told they would call back and they did not. As you would expect the price was too high. They ended up tightening a union of pipes and testing to see if it leaked. The first time it was tightened, it did leak and they went to replace the part. A second tech tightened it further, retested and it did not leak.Not sure why the first person didn't tighten further. So the question remains; is the problem solved. We will see when the heating season begins. The techs were young, personable and seemed knowledgeable and willing to answer all my questions. They spent over two hours here, some of it waiting to get the heating up for testing. Had a $50.00 coupon or the cost would have been over $400."





+9

Serving Derby, CT and surrounding areas
In business since 2001
Free estimates
Emergency services offered
"It was excellent. Ramon was incredibly thorough in terms of checking everything. Anytime there's any issue I can call him and troubleshoot through the phone, and if not, he'll come over and fixed it."





+19

Serving Derby, CT and surrounding areas
In business since 2022
Free estimates
Credit card accepted
We provide residential and commercial solar power options, and provide support services for industry partner companies. We offer no cost consultations and $0 down financing. Please contact our office for a consultation at (931)922-8258.





+3

Serving Derby, CT and surrounding areas
In business since 2005
Free estimates
Emergency services offered
"They did an excellent assessment, were good listeners for our goals, gave us updates as to when the custom windows would arrive, installed promptly and expertly respecting our time limits due to our children's nap schedule, cleaned up, communicated with us through the installation, and we have had reductions in our energy bill since the installation.
"





+41
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