Contractor · Westminster, CO · reviewed since 2019
iHow the Experts Score is calculatedEach factor is scored 0–100 on absolute terms (standing in the category can only raise it), then weighted; problems flagged in review highlights or a recent slide in ratings are subtracted:Satisfaction 59%98+57.5Reliability 26%97+25.3Value 15%100+15.2Craft & service penalty87−1.3Experts Score= 97Not enough data for replies to reviews; its weight is shared by the others.Grade A: A = 80+, B = 60–79, C = 40–59, D = 20–39. Needs 10+ reviews.97SCORE
AGradeiLetter from the Experts Score: A = 80+, B = 60–79, C = 40–59, D = 20–39, F = under 20.
#15 of 56 radon testing servicesiPosition by Experts Score among all companies we track in this category. · better than 75%
5.0★★★★★159 Google reviews · 22 photos
99%five-star reviews
5.00★last 12 monthsiAverage stars on reviews from the last 12 months only.
0%1–2★ in 2 yearsiShare of 1–2★ reviews in the last 24 months — or the 20 newest reviews when the company had fewer than 20 in that time.
Google reviewers rate Mile High Radon Control five stars based on 159 reviews, with the owner responding to 84 percent of them. Customers frequently cite punctuality, clear communication, and fair pricing for radon mitigation services, including crawl space vapor barriers and system repairs. Many note that the team handles difficult installations professionally and offers honest advice, such as suggesting DIY fixes when appropriate. One lower-rated review criticized the visual appearance of an installation and alleged that the company was defensive when addressing the issue.
Google rating: 5.0 out of 5 from 159 reviews (99% five-star).
Reviews on this page: 159 Google reviews (150 with written comments, 13 with photos).
Owner responses: the business replied to 84% of reviews.
Most recent review: October 21, 2026.
Service: Radon Testing Service serving Westminster, Colorado.
Data from Google, last updated October 26, 2026.
Score profile vs other radon testing services
Score per factor (100 = best)iEach factor is scored 0–100 on absolute terms (star average, share of 1–2★ reviews, price verdicts…); standing within the category can only raise it, never lower it.. Strongest: value and momentum; weakest: craft & service.
Mile High Radon ControlRadon Testing Services median0 = centre, 100 = best
SatisfactioniSatisfaction · 54% of the scoreRecency-weighted star average (2-year half-life), shrunk toward the category mean by review volume; the company’s own lifetime average as the prior; absolute: 4.0★ = 0, 5★ = 100.Mile High Radon Control: 98/100 on this factor. Category median: 95.A
98
ReliabilityiReliability · 24% of the scoreHow rarely jobs go badly: share of 1–2★ reviews — 60% the last 24 months (or the 20 newest if fewer), 40% all-time; 0% = 100, 15%+ = 0; the category percentile can only raise it.Mile High Radon Control: 97/100 on this factor. Category median: 95.A
97
Craft & serviceiCraft & service · penalty only, up to −10 pointsGoogle review highlights: Quality, Professionalism, Responsiveness, Punctuality — how rarely reviewers flag them as a negative, per review since highlights began; 0% = 100, 5%+ = 0. Subtracted from the score (up to −10), never averaged in — clean highlights are the norm, not a bonus.Mile High Radon Control: 87/100 on this factor. Category median: 98.A
87
ValueiValue · 14% of the scoreCustomers’ own price verdicts (Great / Reasonable vs Overpriced) and Value highlights; 65% absolute (all “reasonable” ≈ 80, “great” = 100), the category percentile can only raise it.Mile High Radon Control: 100/100 on this factor. Category median: 100.A
100
MomentumiMomentum · penalty only, up to −10 pointsPenalises only a real slide: last-12-month average below lifetime (−0.5★ = 0). Still 4.8★+ over the last year, or steady/improving = 100. Subtracted from the score (up to −10), never averaged in.Mile High Radon Control: 100/100 on this factor. Category median: 100.A
100
Replies to reviewsiReplies to reviews · 7% of the scoreHow often the owner publicly replies to reviews under 5★ (1–4★). Needs 3+ such reviews, otherwise not counted; 65% absolute (80%+ replied = 100), the category percentile can only raise it.Not enough reviews for this factor yet. Category median: 82.–
–
Bar = this company · dark tick = category median.
Star ratings
159 Google reviews we collected
5.0of 5
5 stars15799%
4 stars11%
3 stars00%
2 stars11%
1 star00%
Praise vs complaints
Phrases our text analysis found in 150 written reviews
99%praise
Praise41299%
Complaints31%
PriceiGoogle asks reviewers whether the price was great, reasonable or overpriced; these are their answers.
Price verdicts customers left with their Google review
100%fair
Great price267%
Reasonable133%
Overpriced00%
Not sure00%
Topic share
How often each topic comes up in the written reviews
7topics
Speed & response8621%
Would recommend8320%
Staff & attitude8220%
Quality & results6215%
Price & value5012%
Communication399%
Honesty & trust133%
What customers talk about
We read 150 written reviews and marked every phrase about these topics. The same colors are highlighted in the reviews.
“Darren provided prompt customer service and explained everything needed to mitigate our home.”
“I would highly recommend Darren, his company and his employees for any radon work you might need.”
“Integrity and professionalism, can't recommend them enough.”
“He is a great guy, extremely friendly and knowledgeable and worked very efficiently.”
“He referred us to 1-800-Got-Junk who came and did a wonderful job.”
“I am so glad I put a priority on choosing a local vendor who provided excellent service and results at a reasonable price.”
“They have great communication, follow through on what they say, give proper advice, and just do an outstanding job overall!”
“I can't thank them enough for their honesty and integrity!”
People customers mention
Darren45 reviews
Jimmy8 reviews
Longmont3 reviews
praise complaint · found by our text analysis, Google review wording unchanged.
Reviews for your job
Customers hired Mile High Radon Control for 4 kinds of job. Pick one to see what they paid and said.
Brigitte6 reviewsiTotal number of Google reviews this person has written across all businesses on Google Maps (not just this one). More reviews usually means a more experienced, trustworthy reviewer. · 5 days ago★★★★★
Darren and his team are excellent!! Darren provided prompt customer service and explained everything needed to mitigate our home. Jaden did a stellar job installing our system. Even when our home proved to be a very challenging install with hard cement-like dirt underneath our crawl space, he worked to do the job…
Reasonable price
MikeLocal Guide · 73 reviewsiTotal number of Google reviews this person has written across all businesses on Google Maps (not just this one). More reviews usually means a more experienced, trustworthy reviewer. · a month ago★★★★★
I needed a radon system for a tricky crawlspace/basement. A lot of companies turned me down or gave me an inflated price to not have to deal with it. Darren at Mile Hi worked with me and got the job done! The price was great and so was the quality of the work! Great communication from him and his team. If I ever…
Great price
ColeLocal Guide · 33 reviewsiTotal number of Google reviews this person has written across all businesses on Google Maps (not just this one). More reviews usually means a more experienced, trustworthy reviewer. · a month ago★★★★★
Incredible service, professionalism, and craftsmanship! I wasn't even home, since I had not made the move yet. They were in and out super quickly and these mitigations look absolutely textbook. Almost exactly like their photos on their website!
Denis3 reviewsiTotal number of Google reviews this person has written across all businesses on Google Maps (not just this one). More reviews usually means a more experienced, trustworthy reviewer. · a month ago★★★★★
It has been awesome working with Darren. Fixed my radon problems at a fair price.
Great price
David6 reviewsiTotal number of Google reviews this person has written across all businesses on Google Maps (not just this one). More reviews usually means a more experienced, trustworthy reviewer. · 3 months ago★★★★★
This should be the ONLY radon company you call! They have great communication, follow through on what they say, give proper advice, and just do an outstanding job overall! As a realtor, i interact with many different companies, & these guys are the ones i used on my personal residence for a reason.
Cameron1 reviewiTotal number of Google reviews this person has written across all businesses on Google Maps (not just this one). More reviews usually means a more experienced, trustworthy reviewer. · 4 months ago★★★★★
Darren and Jimmy are the exact type of contractors you should support. Hired them for radon mitigation in my 1967 Longmont home.The clay under the slab is as hard as granite. Notice the clean cut into the slab in my photo. The obstacle didn’t scare them though, they immediately had solutions and were flexible.…
Darren and his team are excellent!! Darren provided prompt customer service and explained everything needed to mitigate our home. Jaden did a stellar job installing our system. Even when our home proved to be a very challenging install with hard cement-like dirt underneath our crawl space, he worked to do the job right. They went above and beyond. Highly recommend!
Price assessment: Reasonable price
Jim Rose6 reviewsiTotal number of Google reviews Jim has written across all businesses on Google Maps, not just this one.
We were referred to Darren at Mile High Radon Control by our neighbors who had positive experiences with his work. On his first visit to our crawl space, he advised us we had to have the area cleaned out before he could do any work. He referred us to 1-800-Got-Junk who came and did a wonderful job. We notified Darren that the crawl space was now cleaned and ready for mitigation. It was a 2-step process. The first being Brandon Dominguez coming and installing the piping and fan system. After consultation with us he was able to install the system in a location of our preference. He is a great guy, extremely friendly and knowledgeable and worked very efficiently. He also made a small fence adjustment to help our gate close. He was a pleasure to have in our house. Two days later, Tyler came and installed the vapor barrier in the crawl space. Since he spent his time down there, we did not interact too much with him, but the little we he was very nice and also very knowledgeable of his tasks. I would highly recommend Darren, his company and his employees for any radon work you might need.
Response from the owner · a week ago
Hi Jim. Thank you for such positive and detailed review! We are very thankful.
Mike PatricioLocal Guide · 73 reviewsiTotal number of Google reviews Mike has written across all businesses on Google Maps, not just this one.
I needed a radon system for a tricky crawlspace/basement. A lot of companies turned me down or gave me an inflated price to not have to deal with it. Darren at Mile Hi worked with me and got the job done! The price was great and so was the quality of the work! Great communication from him and his team. If I ever need another radon system, they will be my first and only call!
Price assessment: Great price
Response from the owner · a week ago
Thank you Mike! We really appreciate your kind words. I’m glad you had a great experience with us.
Cole SwingholmLocal Guide · 33 reviewsiTotal number of Google reviews Cole has written across all businesses on Google Maps, not just this one.
Incredible service, professionalism, and craftsmanship! I wasn't even home, since I had not made the move yet. They were in and out super quickly and these mitigations look absolutely textbook. Almost exactly like their photos on their website!
Response from the owner · a month ago
Thank you Cole! And thank you for trusting us from another state.
Denis Tramarin3 reviewsiTotal number of Google reviews Denis has written across all businesses on Google Maps, not just this one.
This should be the ONLY radon company you call! They have great communication, follow through on what they say, give proper advice, and just do an outstanding job overall! As a realtor, i interact with many different companies, & these guys are the ones i used on my personal residence for a reason.
Response from the owner · 3 months ago
Thank you so much David! It’s always a pleasure for us to be one of your vendors for your team.
Cameron Ferguson1 reviewiTotal number of Google reviews Cameron has written across all businesses on Google Maps, not just this one.
Darren and Jimmy are the exact type of contractors you should support. Hired them for radon mitigation in my 1967 Longmont home.The clay under the slab is as hard as granite. Notice the clean cut into the slab in my photo. The obstacle didn’t scare them though, they immediately had solutions and were flexible. Locally owned and operated. I will only recommend Mile High Radon to my residential HVAC clients moving forward.
Response from the owner · 4 months ago
Cameron thank you for the kind words! We appreciate you taking the time to leave a review.
Kyle8 reviewsiTotal number of Google reviews Kyle has written across all businesses on Google Maps, not just this one.
The team worked incredible hard and were fantastic. I have a small basement / crawl space and they did a fantastic job covering everything that was exposed and installing the system. They were super professional, timely, and kind. I do not envy their job! That is hard work. Would absolutely recommend them to anyone needing radon mitigations
Mike Larremore12 reviewsiTotal number of Google reviews Mike has written across all businesses on Google Maps, not just this one.
