Skip to content
Best in Hood
Menu
Categories Cities Guides How we rank
Get listed

5 Best Insulation Services in Denver (2026)

Ranked by real Google ratings and review volume · How we chose

Brad Smith
By Brad Smith, Home Services Expert · ✓ Updated · 7 min read

We compared 17 insulation services in Denver on Google Maps · 5 listed · How we rank

Sorting insulation services in Denver by star rating gets you nowhere: every business below is rated between 4.9 and 5, and together they hold more than 770 Google reviews. What separates them is the work reviewers actually describe, from attic air sealing and blown-in R-60 to crawl spaces, and who handles the Xcel rebate paperwork.

Short answer: NetZero Insulation in Englewood is the top pick at 4.9 stars from more than 170 Google reviews, with Koala Insulation of Denver at 4.9 on more than 170 and AtticPro Insulation at a perfect 5.0 on more than 130. Reviewers mention Xcel Energy rebates on several of these jobs. Pricing depends on attic size, insulation type and air sealing, so request a written estimate.
Jump to a business

Denver Insulation Contractors at a Glance

# Business Rating Reviews Best for
1 NetZero Insulation 4.9 ★ 179 Attic work with rebate help View ›
2 Koala Insulation of Denver 4.9 ★ 174 Free efficiency review View ›
3 AtticPro Insulation 5.0 ★ 134 Attic R-60 upgrades View ›
4 REenergizeCO 4.9 ★ 146 Energy upgrades and solar View ›
5 Insulation Nation 4.9 ★ 140 Rebates and competitive quotes View ›
5 Best Insulation Services in Denver (2026)

Attic, crawl space and wall specialists, reviewed

NetZero Insulation logo
#1 Overall🕑 Open 6 days/wk

NetZero Insulation

4.9179 Google reviews

NetZero Insulation is an Englewood insulation contractor. Its site lists attic insulation, air sealing, crawl space insulation, insulation removal and replacement, spray foam, fiberglass and cellulose, garage and living-space insulation, soundproofing and energy audits, and it advertises help with Xcel Energy rebates. Reviewers describe attic jobs with before-and-after photos, and in two cases wall or rec room insulation done alongside.

What people praise

  • Before-and-after attic photos shared with customers, according to several reviewers
  • Rebates applied directly to the invoice, per one reviewer who also credited the estimator with walking through each line item
  • Crews that lay down tarps and plastic and leave the house clean
  • One reviewer had a concrete rec room insulated and a disconnected bathroom vent hose fixed during the same visit
Reputation scorecardrank in Denver
Rating4.9 / 5
Review volume179 · 97th
Confidencemoderate
Recency8 weeks ago
Info completenesssite · phone · hours
Rating breakdown97% 5-star
✓ VerifiedSource: Google

Our take: A 4.9 rating on the largest review base here, with detailed accounts of attic air sealing, removal and blown-in insulation. A strong first call for an attic upgrade that involves rebates.

Website+1720-517-0011 Directions

1940 W Adriatic Pl, Englewood, CO 80110

Koala Insulation of Denver logo
#2🕑 Open 5 days/wk↩ Responds to reviews

Koala Insulation of Denver

4.9174 Google reviews

Koala Insulation of Denver is the Denver-area branch of the national Koala Insulation brand, based in Commerce City. Its site lists spray foam, blown-in attic insulation, insulation removal, batt installation, solar attic fans, air sealing, crawl space encapsulation and commercial insulation, and it offers a no-cost home efficiency review. Reviewers describe attic jobs and whole-space upgrades, with a quoting rep named Kayla coming up repeatedly.

What people praise

  • Crews that protect floors and belongings and double-check cleanup, according to one reviewer
  • Plenty of documentation of attic work, so owners did not have to climb up to check
  • One reviewer said the rep later visited again and advised them not to buy unnecessary services from a pest company
  • A consultation and quote handled in person by the same rep who returns for testing on install day

Worth knowing

  • One four-star review mentions a lot of dust to clean up afterward and some difficulty communicating with one crew member
Reputation scorecardrank in Denver
Rating4.9 / 5
Review volume174 · 91st
Confidencemoderate
Recency2 months ago
Info completenesssite · phone · hours
Rating breakdown97% 5-star
✓ VerifiedSource: Google

Our take: A branch of a national brand whose rating and review volume sit close to the top pick's. Reviewers keep naming the quoting rep, so it is worth asking who will visit your house.

Website+1720-824-6030 Directions

6185 E 56th Ave, Commerce City, CO 80022

AtticPro Insulation logo
#3🕑 Open 7 days↩ Responds to reviews

AtticPro Insulation

5.0134 Google reviews

AtticPro Insulation is a Lakewood insulation contractor that takes bookings online. Its site lists attic insulation, wall insulation, spray foam, blown-in insulation, insulation removal, rodent proofing, crawl space encapsulation, attic air sealing and solar attic fans, plus help with rebates and financing. Reviewers describe attic jobs, several of them R-60 blown-in upgrades on Lakewood and Denver homes.

What people praise

  • One reviewer said the crew sealed gaps around pipes and ductwork before upgrading the insulation
  • Help understanding the available Xcel Energy rebate options, per one reviewer
  • On-time crews that leave the attic clean, according to reviewers
  • One reviewer noticed the difference in the house right away after attic work

Worth knowing

  • Reviewers describe attic insulation jobs; its site also lists wall, spray foam and crawl space work that they do not mention
Reputation scorecardrank in Denver
Rating5 / 5
Review volume134 · 74th
Confidencemoderate
Recency7 weeks ago
Info completenesssite · phone · hours
Rating breakdown100% 5-star
✓ VerifiedSource: Google

Our take: Perfect 5.0 on the smallest review base on this page. A solid fit for a straightforward attic upgrade, and a reasonable call to compare against the larger names.

Website Book now+1720-343-2337 Directions

720 Kipling St #12, Lakewood, CO 80215

REenergizeCO logo
#4🕑 Open 5 days/wk↩ Responds to reviews

REenergizeCO

4.9146 Google reviews

REenergizeCO is a Denver energy-efficiency contractor on East 58th Avenue. Google lists it as an insulation contractor and a solar energy company, and reviewers describe attic and crawl space insulation, air sealing, a full HVAC system overhaul through an energy-upgrade program, and solar panel installation with a home battery.

What people praise

  • A crew that hauled equipment by hand up a steep driveway and left no trace of mess, according to one reviewer
  • Attic and basement resealed before new insulation was blown in, said one reviewer
  • Responsive support after a solar install, including help with an inverter issue
  • One reviewer with solar-industry experience called the install quality impressive

Worth knowing

  • One reviewer in the CARE energy program described about a year from application to completion, including a wait of about 10 months before the energy audit
Reputation scorecardrank in Denver
Rating4.9 / 5
Review volume146 · 85th
Confidencemoderate
Recency3 months ago
Info completenesssite · phone · hours
Rating breakdown96% 5-star
✓ VerifiedSource: Google

Our take: Rated 4.9 and stands out for pairing insulation and air sealing with solar and HVAC work. A good pick if you want the whole energy upgrade handled by one company.

Website+1303-227-1000 Directions

1805 E 58th Ave Unit K, Denver, CO 80216

Insulation Nation logo
#5🕑 Open 5 days/wk↩ Responds to reviews

Insulation Nation

4.9140 Google reviews

Insulation Nation is a Denver insulation company on West Warren Avenue. Its site lists attic insulation, cellulose and fiberglass blow-in, attic air sealing, a radiant barrier, crawl space insulation, batt insulation and Xcel Energy rebate processing in six metro-area counties. Reviewers describe attic sealing and blow-in jobs, quotes sent by email before a visit and crews that cleaned up well.

What people praise

  • Reviewers call the rates competitive, with one comparing three estimates before choosing
  • A crew that was professional, quick and answered questions, per several reviewers
  • One reviewer tested the result in a cold snap and said the room held its temperature much longer
  • A project scheduled within two weeks, according to one reviewer
Reputation scorecardrank in Denver
Rating4.9 / 5
Review volume140 · 79th
Confidencemoderate
Recency5 months ago
Info completenesssite · phone · hours
Rating breakdown96% 5-star
✓ VerifiedSource: Google

Our take: A 4.9 rating with feedback centered on attic sealing, fiberglass blow-in and rebate processing. A sensible bid to collect alongside the larger names.

Website+1720-410-9414 Directions

4665 W Warren Ave, Denver, CO 80219

6

Your business here

Get listed on this page, in front of local customers already searching for you.

Claim this spot ›

Reading the scorecards

Each number here comes from public Google data on the date shown. Rating is the live Google star average. Review volume is how many customers have rated the business, compared with other Denver insulation contractors. Confidence weighs the rating by that volume, which matters when every rating is close. Recency reflects how recently customers still review. No business can edit these figures.

What shapes insulation cost in Denver (2026)

Insulation pricing depends on the size of the attic or wall area, the insulation type (blown-in fiberglass, cellulose or spray foam), whether old material must be removed and how much air sealing is needed first. Xcel Energy rebates can lower the final bill, and some contractors in this list apply them directly to the invoice, so ask how that works.

Insulation contractors serving the Denver metro

These businesses are based in Englewood, Commerce City, Lakewood and Denver itself. Insulation Nation’s site lists service in Denver, Douglas, Jefferson, Arapahoe, Adams and Broomfield counties, and AtticPro works Lakewood and the wider metro. Searching for insulation services near me? Each listing shows a direct phone number and map link.

Questions for an insulation contractor

  • Will you air seal the attic before adding insulation?
  • What R-value are you recommending for my attic, and why?
  • Do you process the Xcel Energy rebate, and is it applied to the invoice or paid back to me later?
  • Will you take before-and-after photos of the attic?
  • How will you protect floors and contain dust inside the house?

Frequently asked questions

Do Denver insulation contractors handle the Xcel Energy rebate paperwork?

Several do. One NetZero reviewer said the rebates were applied directly to the invoice so they did not have to front the money, and another said NetZero introduced them to the Xcel programs. Insulation Nation’s site says it processes rebates in-house, and an AtticPro reviewer said the crew helped explain the rebate options.

Which of these insulation contractors also do air sealing?

Reviewers describe air sealing along with insulation at NetZero, AtticPro, REenergizeCO and Insulation Nation, and Koala’s site lists an air sealing service. Ask any contractor whether sealing is part of the quote or an extra line.

Is there an insulation company here that also installs solar panels?

REenergizeCO. Google lists it as both an insulation contractor and a solar energy company, and one reviewer bought a 10 kW solar system with a battery from it while another had solar panels plus air sealing and insulation done. Koala’s site lists solar attic fans, which are a ventilation product rather than solar panels.

What documentation should I expect after an attic insulation job in Denver?

Photos are the common one. NetZero reviewers describe before-and-after attic photos, and one also received a certificate for future home inspections. A Koala reviewer said they got plenty of documentation of the attic work so they did not need to climb up themselves.

Where to start

NetZero Insulation is the safe default for an attic upgrade with rebate help, with Koala and Insulation Nation worth pricing against it. Choose REenergizeCO if solar or HVAC work is part of the plan. Get the estimate in writing, with the rebate treatment spelled out.

Own one of these businesses, or want to be here?

Claim your spot on this page: Basic listing $50 or Premium $100 for the top spot, held a full year. Both include a permanent link to your site.

Get listed See pricing