Before you hire any of the insulation contractors in your area, get four things from them. Ask for the city contractor license number, an insurance certificate for liability and workers’ comp, and proof the crew is trained, with BPI certification being the most common. Then get a written quote that names the material, the R-value, the square footage and the air sealing. A company that can’t hand those over is one we’d skip.
We should be upfront here. Grizzly Insulation Co is one of the companies you probably found, so we’re not exactly neutral. But this is honestly the list we’d want our own parents to use before letting anybody up into their attic.
Does an Insulation Contractor Need a License in Colorado?
Not from the state, which surprises a lot of people. Colorado leaves contractor licensing to each city and county, so the rules in Aurora might not match the ones in Lakewood or Boulder.
Denver’s version is easy to follow. The city’s contractor licensing page describes a two-step process, and the permit office says any contractor doing work inside city limits needs the right license, along with a supervisor certificate when the job calls for one. If you’re out in the suburbs, your own building department can tell you what applies in a quick phone call.
How Do You Check an Insulation Contractor's Credentials?
A good contractor expects you to check, and won’t mind when you do. These are the five things we’d want to see from any company, including ours:
A license number that the city or county can confirm.
An insurance certificate for general liability and workers’ comp, mailed or emailed to you by the insurance company itself.
BPI certification, which tells you the crew has been trained by the Building Performance Institute on air sealing, ventilation and safety testing.
Rebate know-how. If you’re counting on an Xcel Energy rebate, the contractor may need to be part of Xcel’s program.
References and reviews. Recent customers you can phone, and reviews that describe real jobs instead of just stars.
In our experience, the companies that get prickly about this list are the ones you’d regret hiring.
Why Does Insurance Matter When Hiring an Insulation Contractor?
Attics are rough places to work. Crews balance on joists, reach around wiring and, every so often, a boot goes through a ceiling. Without insurance, an injury or a busted ceiling can turn into your problem instead of theirs.
Liability coverage pays for damage to your home. Workers’ comp pays for injuries to the crew. The certificate should come straight from the insurer, and it’s worth glancing at the dates to make sure the policy hasn’t lapsed.
Should an Insulation Contractor Test Your Home First?
A good one will. A blower door test measures how leaky the house is before and after the work, so you can see the air sealing actually did something. BPI-trained contractors also check gas appliances, like the furnace and water heater, to make sure they still vent safely once the house is tighter.
Ask about bag labels too. The Insulation Institute advises homeowners to deal in R-values, not inches, and to avoid any contractor who uses unlabeled bags. For blown-in work, the R-value depends on how much material goes in, not just how deep it looks.
What Should a Good Insulation Quote Include?
A clear quote spells out exactly what you’re paying for. Look for:
The material, such as blown fiberglass, cellulose or closed cell spray foam.
The target R-value and depth, or the number of bags for blown-in.
The square footage being covered.
Air sealing, listed as its own line, with the spots it covers.
Baffles and vents, so the attic still breathes.
Removal of old insulation, if needed.
Cleanup, warranty and timeline.
If two quotes look far apart, compare them line by line. Often the cheaper one skips air sealing. Our guide on how much insulation an attic needs helps you check the R-value they’re promising, and types of attic insulation explains the materials.
Should an Insulation Contractor Air Seal Before Insulating?
Yes. The testing on this is clear. ENERGY STAR’s savings estimates for homeowners count air sealing and insulation together, because insulation works far better when air isn’t leaking through it. A crew that blows insulation over open gaps around lights, pipes and the attic hatch is leaving savings on the table.
So where does the idea that “more insulation fixes everything” come from? Mostly from sales pitches. Nobody has shown that piling on R-value makes up for a leaky ceiling. If your attic were ours, we’d insist on seeing the air sealing plan before any insulation goes in. Our air sealing service blog shows what that work looks like.
What Are the Red Flags When Hiring an Insulation Contractor?
Here are the warning signs homeowners tell us about most:
Door-to-door pressure with a “today only” price.
Huge savings promises, like cutting your bill in half with one product.
No written quote, or a quote with only a total price.
Cash only, or a large deposit before any work starts.
Radiant barrier pitches are a common one in our area. They’re often sold with big savings claims, but in a cold, heating-heavy climate like ours, the benefit is usually small.
What Questions Should You Ask an Insulation Contractor?
Ask these before you sign:
What R-value will my attic or walls have when you’re done?
Will you air seal first, and where?
Does the old insulation need to come out? Why or why not?
How Can You Tell the Insulation Job Was Done Right?
Check the attic when the crew is done. For blown-in attic insulation, the code requires depth markers, usually rulers stapled to the trusses, about one for every 300 square feet. You should also see a certificate near the attic access listing the material, the R-value and the installed thickness.
Look for an even layer with no bare spots, baffles at the soffits, and a sealed, insulated attic hatch. Ask for before-and-after photos, too. A good crew takes them without being asked.
Are There Rebates When You Hire an Insulation Contractor?
Often, yes. Xcel Energy runs rebate programs for insulation and air sealing in Colorado, and some rebates require a participating contractor. Federal tax credits have also covered insulation for many homeowners. Our blog on the new insulation tax credit explains what to ask about, and energy efficient insulation covers which upgrades tend to qualify.
Should You Hire an Insulation Specialist or a General Contractor?
For insulation work on its own, a specialist is usually the better call. General contractors often hand insulation to a subcontractor anyway, and that adds a layer between you and the crew in your attic. A specialist owns the whole job, from testing and air sealing to the final depth check.
Specialists also tend to have the gear that makes the work cleaner. That includes blowing machines, sealed vacuum systems for pulling out old insulation, and spray rigs with trained operators. If your old insulation is moldy or full of rodent mess, ask whether they handle removal themselves, like our insulation removal crew does.
A general contractor makes sense when insulation is one piece of a bigger remodel, like a kitchen addition or a finished basement. Even then, ask who will actually install it and check that company’s credentials too. For foam jobs, ask whether the installer sprays foam every week, the way our spray foam insulation team does, or only now and then.
How Much Should You Expect to Pay an Insulation Contractor?
Prices vary by material, access and how much air sealing your home needs, so get at least two or three written quotes. Blown-in attic insulation is usually the most affordable big upgrade. Spray foam costs more but seals and insulates in one step. Be wary of any quote far below the others, since corners have to be cut somewhere.
Conclusion
The right installer is licensed where you live, insured, trained, and happy to put everything in writing. Check those boxes, compare quotes line by line, and ask about air sealing, and you’ll avoid most of the headaches people run into. Our guide to signs your home needs better insulation can help you decide what to ask for.
We’d love to be on your shortlist. Grizzly Insulation Co is BPI Certified and an Xcel Energy rebate partner, and we put every quote in writing.
Call (303) 854-6221 to have us look at your Denver home and check out our attic insulation service.
How to Choose an Insulation Contractor in Your Area and Check a Denver Installer’s Credentials
Before you hire any of the insulation contractors in your area, get four things from them. Ask for the city contractor license number, an insurance certificate for liability and workers’ comp, and proof the crew is trained, with BPI certification being the most common. Then get a written quote that names the material, the R-value, the square footage and the air sealing. A company that can’t hand those over is one we’d skip.
We should be upfront here. Grizzly Insulation Co is one of the companies you probably found, so we’re not exactly neutral. But this is honestly the list we’d want our own parents to use before letting anybody up into their attic.
Does an Insulation Contractor Need a License in Colorado?
Not from the state, which surprises a lot of people. Colorado leaves contractor licensing to each city and county, so the rules in Aurora might not match the ones in Lakewood or Boulder.
Denver’s version is easy to follow. The city’s contractor licensing page describes a two-step process, and the permit office says any contractor doing work inside city limits needs the right license, along with a supervisor certificate when the job calls for one. If you’re out in the suburbs, your own building department can tell you what applies in a quick phone call.
How Do You Check an Insulation Contractor's Credentials?
A good contractor expects you to check, and won’t mind when you do. These are the five things we’d want to see from any company, including ours:
In our experience, the companies that get prickly about this list are the ones you’d regret hiring.
Why Does Insurance Matter When Hiring an Insulation Contractor?
Attics are rough places to work. Crews balance on joists, reach around wiring and, every so often, a boot goes through a ceiling. Without insurance, an injury or a busted ceiling can turn into your problem instead of theirs.
Liability coverage pays for damage to your home. Workers’ comp pays for injuries to the crew. The certificate should come straight from the insurer, and it’s worth glancing at the dates to make sure the policy hasn’t lapsed.
Should an Insulation Contractor Test Your Home First?
A good one will. A blower door test measures how leaky the house is before and after the work, so you can see the air sealing actually did something. BPI-trained contractors also check gas appliances, like the furnace and water heater, to make sure they still vent safely once the house is tighter.
Ask about bag labels too. The Insulation Institute advises homeowners to deal in R-values, not inches, and to avoid any contractor who uses unlabeled bags. For blown-in work, the R-value depends on how much material goes in, not just how deep it looks.
What Should a Good Insulation Quote Include?
A clear quote spells out exactly what you’re paying for. Look for:
If two quotes look far apart, compare them line by line. Often the cheaper one skips air sealing. Our guide on how much insulation an attic needs helps you check the R-value they’re promising, and types of attic insulation explains the materials.
Should an Insulation Contractor Air Seal Before Insulating?
Yes. The testing on this is clear. ENERGY STAR’s savings estimates for homeowners count air sealing and insulation together, because insulation works far better when air isn’t leaking through it. A crew that blows insulation over open gaps around lights, pipes and the attic hatch is leaving savings on the table.
So where does the idea that “more insulation fixes everything” come from? Mostly from sales pitches. Nobody has shown that piling on R-value makes up for a leaky ceiling. If your attic were ours, we’d insist on seeing the air sealing plan before any insulation goes in. Our air sealing service blog shows what that work looks like.
What Are the Red Flags When Hiring an Insulation Contractor?
Here are the warning signs homeowners tell us about most:
Radiant barrier pitches are a common one in our area. They’re often sold with big savings claims, but in a cold, heating-heavy climate like ours, the benefit is usually small.
What Questions Should You Ask an Insulation Contractor?
Ask these before you sign:
On removal, an honest answer is often “no.” Dry, clean insulation can usually stay. See whether to remove old insulation first.
How Can You Tell the Insulation Job Was Done Right?
Check the attic when the crew is done. For blown-in attic insulation, the code requires depth markers, usually rulers stapled to the trusses, about one for every 300 square feet. You should also see a certificate near the attic access listing the material, the R-value and the installed thickness.
Look for an even layer with no bare spots, baffles at the soffits, and a sealed, insulated attic hatch. Ask for before-and-after photos, too. A good crew takes them without being asked.
Are There Rebates When You Hire an Insulation Contractor?
Often, yes. Xcel Energy runs rebate programs for insulation and air sealing in Colorado, and some rebates require a participating contractor. Federal tax credits have also covered insulation for many homeowners. Our blog on the new insulation tax credit explains what to ask about, and energy efficient insulation covers which upgrades tend to qualify.
Should You Hire an Insulation Specialist or a General Contractor?
For insulation work on its own, a specialist is usually the better call. General contractors often hand insulation to a subcontractor anyway, and that adds a layer between you and the crew in your attic. A specialist owns the whole job, from testing and air sealing to the final depth check.
Specialists also tend to have the gear that makes the work cleaner. That includes blowing machines, sealed vacuum systems for pulling out old insulation, and spray rigs with trained operators. If your old insulation is moldy or full of rodent mess, ask whether they handle removal themselves, like our insulation removal crew does.
A general contractor makes sense when insulation is one piece of a bigger remodel, like a kitchen addition or a finished basement. Even then, ask who will actually install it and check that company’s credentials too. For foam jobs, ask whether the installer sprays foam every week, the way our spray foam insulation team does, or only now and then.
How Much Should You Expect to Pay an Insulation Contractor?
Prices vary by material, access and how much air sealing your home needs, so get at least two or three written quotes. Blown-in attic insulation is usually the most affordable big upgrade. Spray foam costs more but seals and insulates in one step. Be wary of any quote far below the others, since corners have to be cut somewhere.
Conclusion
The right installer is licensed where you live, insured, trained, and happy to put everything in writing. Check those boxes, compare quotes line by line, and ask about air sealing, and you’ll avoid most of the headaches people run into. Our guide to signs your home needs better insulation can help you decide what to ask for.
We’d love to be on your shortlist. Grizzly Insulation Co is BPI Certified and an Xcel Energy rebate partner, and we put every quote in writing.
Call (303) 854-6221 to have us look at your Denver home and check out our attic insulation service.
Frequently Asked Questions
Search locally, then check each one’s license, insurance and reviews before calling.
The city requires all contractors working there to hold the appropriate license. Check with the city for your specific job.
It’s a credential from the Building Performance Institute showing training in home energy, air sealing and safety.
At least two or three, compared line by line.
A small deposit is normal. Avoid large upfront payments.