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Verified Reviews for Energy Efficiency Auditing pros in Williams, CA

*The Angi rating for Energy Efficiency Auditing companies in Williams, CA 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 Williams, CA 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 October 04, 2025

Find Energy efficiency auditors in Williams

RSS Solar

Aurora Ave.
No reviews yet

RSS Solar

Aurora Ave.
No reviews yet
Free onsite estimate

We make solar simple-- We are dedicated to making solar energy affordable and accessible to everyone-- with ZERO upfront costs.* Your home can become its own tiny power station and generate plenty of reliable energy, all while reducing your electricity bill. Plus, it doesn't hurt that your greener lifestyle will help your state achieve its renewable energy goals.

We make solar simple-- We are dedicated to making solar energy affordable and accessible to everyone-- with ZERO upfront costs.* Your home can become its own tiny power station and generate plenty of reliable energy, all while reducing your electricity bill. Plus, it doesn't hurt that your greener lifestyle will help your state achieve its renewable energy goals.

USA Alarm Service, Inc

510 S Clearwater Loop
No reviews yet

USA Alarm Service, Inc

510 S Clearwater Loop
No reviews yet
29 years of experience

USA Alarm is a national company that has more than two decades of experience and an award winning command center that protects more than 700,000 homes and businesses through the United States, 24 hours a day and 7 days a week. We have offices located throughout the US, with two main offices in Indianapolis, Indiana and Post Falls, Idaho.

USA Alarm is a national company that has more than two decades of experience and an award winning command center that protects more than 700,000 homes and businesses through the United States, 24 hours a day and 7 days a week. We have offices located throughout the US, with two main offices in Indianapolis, Indiana and Post Falls, Idaho.

NRG Clean Power

7012 OWENSMOUTH AVE
4.58(
43
)

NRG Clean Power

7012 OWENSMOUTH AVE
4.58(
43
)
Customers say: Terrific value
25 years of experience

NRG Clean Power is California’s leading clean power provider. We leverage over 30 years of superior customer service installing solar from the south of San Diego to the northern border with Oregon. In other words, regardless of where you are in California, we can help you make the switch to solar! Not only do we offer top-tier solar services, we are also a total home performance company, devoted to sustainability and energy efficiency. We offer fully customized home and business solar installations with battery backup capabilities. We do not service solar systems that we did not install. We believe the future is clean, renewable energy and with your help we are committed to creating it together. Customer satisfaction is a crucial aspect and the cornerstone of our business. As a result, we have earned the prestigious Diamond Certification 4 years in a row, along with the 2019 Angie’s List Super Service Award. NRG Clean Power offers the finest solar products at the best rates with finance options for everyone. We will be with you every step of the way and for years to come. Check out our promos to take advantage of our best deals. And ask about our Referral Program that allows customers like you to earn cash bonuses for referring friends and family!

"No doubt they hire great installation people, but their communication and honoring their quotes has little to be desired. I will elaborate. I was given a quote, left on my voicemail. I responded the next day letting NRG know I accepted their quote. 1 week later I received a phone call telling me they wouldn't honor the quote give, and they cited the reasons as Tarif's. This was back in April 2025. I still went with NRG, albeit at a$1000.00 increase. The second reason I wouldn't recommend this company, and this for me is the final straw, after installing my solar NRG didn't let me know I needed to have an ESR release, in layman's terms this is necessary for your power company to accept your new solar system. I found out this information when they contacted me in August 2025. NEG blamed the company who upgraded my Electrical Panel. NRG INSTALLED MY SOLAR AFTER THE PANEL WAS UPGRADED. Since this company doesn't communicate with its clients I would say go with another company."

Daniel S on August 2025

NRG Clean Power is California’s leading clean power provider. We leverage over 30 years of superior customer service installing solar from the south of San Diego to the northern border with Oregon. In other words, regardless of where you are in California, we can help you make the switch to solar! Not only do we offer top-tier solar services, we are also a total home performance company, devoted to sustainability and energy efficiency. We offer fully customized home and business solar installations with battery backup capabilities. We do not service solar systems that we did not install. We believe the future is clean, renewable energy and with your help we are committed to creating it together. Customer satisfaction is a crucial aspect and the cornerstone of our business. As a result, we have earned the prestigious Diamond Certification 4 years in a row, along with the 2019 Angie’s List Super Service Award. NRG Clean Power offers the finest solar products at the best rates with finance options for everyone. We will be with you every step of the way and for years to come. Check out our promos to take advantage of our best deals. And ask about our Referral Program that allows customers like you to earn cash bonuses for referring friends and family!

"No doubt they hire great installation people, but their communication and honoring their quotes has little to be desired. I will elaborate. I was given a quote, left on my voicemail. I responded the next day letting NRG know I accepted their quote. 1 week later I received a phone call telling me they wouldn't honor the quote give, and they cited the reasons as Tarif's. This was back in April 2025. I still went with NRG, albeit at a$1000.00 increase. The second reason I wouldn't recommend this company, and this for me is the final straw, after installing my solar NRG didn't let me know I needed to have an ESR release, in layman's terms this is necessary for your power company to accept your new solar system. I found out this information when they contacted me in August 2025. NEG blamed the company who upgraded my Electrical Panel. NRG INSTALLED MY SOLAR AFTER THE PANEL WAS UPGRADED. Since this company doesn't communicate with its clients I would say go with another company."

Daniel S on August 2025

Solar Wolf Energy

202 Worcester St
2.00(
2
)

Solar Wolf Energy

202 Worcester St
2.00(
2
)
10 years of experience

Solar Wolf is a full service solar company with a great reputation and an old world belief to our customers. To under-promise and over-deliver, period. We have 18 years experience in construction, remodeling, roofing, solar water heaters, solar pv systems, battery back-up systems and much more. See what Solar Wolf Energy can do for you!

Solar Wolf is a full service solar company with a great reputation and an old world belief to our customers. To under-promise and over-deliver, period. We have 18 years experience in construction, remodeling, roofing, solar water heaters, solar pv systems, battery back-up systems and much more. See what Solar Wolf Energy can do for you!

Landmark Energy Upgrades

12515 Sherman Way
4.89(
56
)

Landmark Energy Upgrades

12515 Sherman Way
4.89(
56
)
Customers say: Super punctual
Recommended by 98% of Angi customers
Recommended by 98% of HomeAdvisor customers

Whether your project is a new construction, custom built home, an existing remodel, or an energy efficient upgrade, Landmark Construction has the industry experience and skilled staff to make your construction project a success. Our goal is to save you money through energy-efficient construction. Landmark Construction is California’s premier Air-Conditioning Contractor and Heating Contractor. Along with HVAC contracting we can better regulate your home’s temperature with new insulation and a new roof. Landmark Construction doesn’t stop at just energy upgrades. When it comes to renovations of existing homes, we pride ourselves in the ability to maintain your home’s charm and style with solutions for every kind of interior need from tile, drywall accents and wainscoting detail, cabinetry and countertop selection, to redesigning entire interior floor plans. Our network of interior designers can help you get just the look you envisioned from your remodeling or new construction project. We proudly serve Southern California including Bel Air, San Marino, Malibu, Calabasas, Beverly Hills, Century City, Encino, Brentwood and everywhere in between! When clients want to build it strong, build it beautiful, they build it Landmark! Do not hesitate to contact us regarding your next general construction project in Southern California. We look forward to providing you with a free, no obligation consultation today!

"Ezra and Charles are very friendly and personable. That is, when they want to take your money. What good is a 12-year warranty if you start ignoring your customers at 2 years. I needed my HVAC replaced. Because the HVAC sits on my roof, I decided to redo the roof too. Ezra and Charles came out and were really friendly so I immediately had a good impression of them. Even though it would’ve been cheaper to go with a roofer and a separate HVAC company, I decided to go with Landmark Construction Crew, aka Landmark Energy Upgrades. I figured it would be a more seamless process for one company to do both. I got this done in December of 2016. The thing with a roof is that you don’t know if it’s a good job or not until it rains so I waited to write a review. Around January 2018 ( a little over a year later ) we got some much needed rain but unfortunately, I had a leak coming from one of my vents. I emailed Ezra and he sent out a roofer. The roofer came, looked at the vent, jumped up on the roof for ten minutes and said he was done. Months later, it rained again, it leaked again, I emailed Ezra again. I decided to take a closer look at the vent and noticed that there was sunlight in the ductwork. I figured sunlight equals gap somewhere. When the roofer came, I told him and he said it’s nothing, probably just a reflection, without even taking a look. Then the roofer tells me that the next time there is a leak, I need to call the HVAC guy because it’s not a roof problem. I couldn’t believe it so I told him that HIS company IS the HVAC guy!! I used one company to do the roof and the HVAC so there is NOBODY else to blame. So, he jumps back on the roof and was done and gone in 10 minutes. About a month goes by and the rain is back and so is my leak. It’s 2019 so it rained a lot this year. Good for California, bad for me. So, I emailed Ezra again. After a few weeks, no reply. So, I email him again with pictures, a few more weeks go by and no reply. So, I call him and he picked up the phone. He sounded surprised to hear from me (probably didn’t recognize my phone number) and I start telling him about the leak. He said he didn’t get my emails but just text him my address and he’ll send somebody. A couple of weeks goes by and nothing. So, I text him again and after weeks and weeks of waiting, no reply. I’ve emailed, called, and texted so, at this point, it’s very obvious he’s avoiding me. If you are looking for a friendly company that is willing to take your hard-earned cash then Landmark is for you. But if you’re looking for a company that is accountable for their work then look elsewhere. I know I am."

Tony T on March 2019

Whether your project is a new construction, custom built home, an existing remodel, or an energy efficient upgrade, Landmark Construction has the industry experience and skilled staff to make your construction project a success. Our goal is to save you money through energy-efficient construction. Landmark Construction is California’s premier Air-Conditioning Contractor and Heating Contractor. Along with HVAC contracting we can better regulate your home’s temperature with new insulation and a new roof. Landmark Construction doesn’t stop at just energy upgrades. When it comes to renovations of existing homes, we pride ourselves in the ability to maintain your home’s charm and style with solutions for every kind of interior need from tile, drywall accents and wainscoting detail, cabinetry and countertop selection, to redesigning entire interior floor plans. Our network of interior designers can help you get just the look you envisioned from your remodeling or new construction project. We proudly serve Southern California including Bel Air, San Marino, Malibu, Calabasas, Beverly Hills, Century City, Encino, Brentwood and everywhere in between! When clients want to build it strong, build it beautiful, they build it Landmark! Do not hesitate to contact us regarding your next general construction project in Southern California. We look forward to providing you with a free, no obligation consultation today!

"Ezra and Charles are very friendly and personable. That is, when they want to take your money. What good is a 12-year warranty if you start ignoring your customers at 2 years. I needed my HVAC replaced. Because the HVAC sits on my roof, I decided to redo the roof too. Ezra and Charles came out and were really friendly so I immediately had a good impression of them. Even though it would’ve been cheaper to go with a roofer and a separate HVAC company, I decided to go with Landmark Construction Crew, aka Landmark Energy Upgrades. I figured it would be a more seamless process for one company to do both. I got this done in December of 2016. The thing with a roof is that you don’t know if it’s a good job or not until it rains so I waited to write a review. Around January 2018 ( a little over a year later ) we got some much needed rain but unfortunately, I had a leak coming from one of my vents. I emailed Ezra and he sent out a roofer. The roofer came, looked at the vent, jumped up on the roof for ten minutes and said he was done. Months later, it rained again, it leaked again, I emailed Ezra again. I decided to take a closer look at the vent and noticed that there was sunlight in the ductwork. I figured sunlight equals gap somewhere. When the roofer came, I told him and he said it’s nothing, probably just a reflection, without even taking a look. Then the roofer tells me that the next time there is a leak, I need to call the HVAC guy because it’s not a roof problem. I couldn’t believe it so I told him that HIS company IS the HVAC guy!! I used one company to do the roof and the HVAC so there is NOBODY else to blame. So, he jumps back on the roof and was done and gone in 10 minutes. About a month goes by and the rain is back and so is my leak. It’s 2019 so it rained a lot this year. Good for California, bad for me. So, I emailed Ezra again. After a few weeks, no reply. So, I email him again with pictures, a few more weeks go by and no reply. So, I call him and he picked up the phone. He sounded surprised to hear from me (probably didn’t recognize my phone number) and I start telling him about the leak. He said he didn’t get my emails but just text him my address and he’ll send somebody. A couple of weeks goes by and nothing. So, I text him again and after weeks and weeks of waiting, no reply. I’ve emailed, called, and texted so, at this point, it’s very obvious he’s avoiding me. If you are looking for a friendly company that is willing to take your hard-earned cash then Landmark is for you. But if you’re looking for a company that is accountable for their work then look elsewhere. I know I am."

Tony T on March 2019

Liberty Solar

3414 Putter Place
5.00(
1
)

Liberty Solar

3414 Putter Place
5.00(
1
)
Customers say: Quick response
Recommended by 100% of Angi customers
Recommended by 100% of HomeAdvisor customers

Liberty Solar designs, engineers, and installs Advanced Renewable Energy Systems. We do NOT use sub-contractors. We take great pride in our work and we install only the best American-made equipment and the best prices. We have many financing options available.

Liberty Solar designs, engineers, and installs Advanced Renewable Energy Systems. We do NOT use sub-contractors. We take great pride in our work and we install only the best American-made equipment and the best prices. We have many financing options available.

Energytech Inc. DBA Advance Power Redding

843 N. Market St.
No reviews yet

Energytech Inc. DBA Advance Power Redding

843 N. Market St.
No reviews yet
24 years of experience

Wholesale & retail renewable energy store specializing in energy conservation & production. We install solar or sell you the materials. We stock Solar panels, 6v batteries, LIPO-4 batteries, DC to AC power inverters, wind turbines, Hydro turbines & parts, radiant barrier foil, Son Shield insulating paint & roof coat. And much more.

Wholesale & retail renewable energy store specializing in energy conservation & production. We install solar or sell you the materials. We stock Solar panels, 6v batteries, LIPO-4 batteries, DC to AC power inverters, wind turbines, Hydro turbines & parts, radiant barrier foil, Son Shield insulating paint & roof coat. And much more.

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FAQs for energy efficiency auditing projects in Williams, CA

An energy audit costs about $420 on average, ranging from $100 to $2,250, depending on the size of your home, property, location, and the tests the auditor needs to perform. Keep in mind that the 2022 Inflation Reduction Act’s Energy Efficient Home Improvement credit covers up to $150 of home energy audit costs. Common energy audit tests include:

  • Blower door test: $350

  • Duct testing: $100

  • HERS test: $375

  • HERS certification: $200

  • Infrared imaging: $200

The difference between an energy auditor and a home inspector is primarily in the purpose of the inspection. The energy auditor conducts tests in your home to determine the energy efficiency levels in areas like windows, insulation, and doorways. The auditor then makes recommendations for ways to improve a home’s energy efficiency. 

A home inspector examines various structures of your home to determine that everything is up to code and gauge the condition of features like the roof, foundation, HVAC, and electrical. The home inspector reports on the overall home and makes repair recommendations.

Typically, a local home energy auditor is responsible for performing energy audits. A home energy auditor will conduct one of three energy audits designed by the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) to determine the energy efficiency of your home. The auditor often provides analysis that can help guide changes and improvements to your home for better energy efficiency, giving recommendations as necessary.

The three levels of home energy audits include:

  • Level 1: Review of your energy bills and home for signs of energy inefficiency and areas for improvement. The average cost range is $0.08 to $0.12 per square foot.

  • Level 2: A level 2 ASHRAE energy audit costs $0.12 and $0.35 per square foot. In-depth analysis of your energy usage and provides a report of cost-saving changes.

  • Level 3: Comprehensive analysis and detailed recommendations for ways to improve your home’s energy efficiency. A level 3 audit costs about $0.36 to $0.50 per square foot.

To find a reputable energy auditor, find a local company that offers energy audit services. Research the company’s reviews, methods, and certifications to find a reliable professional in your area. The most reputable energy audit companies are HEP-certified by the Building Performance Institute (BPI). Be sure to check our state licensing tool to review the local energy auditor guidelines to ensure you’re hiring a certified professional.

The Williams, CA homeowners’ guide to energy efficiency auditing services

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