⭐⭐⭐⭐⭐ Trusted by Denver-area homeowners · 150+ insulation projects completed
Insulation Contractors in Longmont, CO
From the early-1900s Victorians and brick bungalows of Old Town Longmont to the newer subdivisions out toward Prospect and McIntosh Lake, one certified local crew handles your attic insulation, air sealing, and rodent defense — and backs every job with a 100% guarantee.
- Free, itemized estimates
- Financing available
- Most attics done in 1–2 days
- Serving Longmont, CO and all of Jefferson County
Get Your Free Longmont Estimate
Takes 30 seconds. We reply within 24 hours, no pressure, no spam.
1–2 Days
Most Projects Completed
R-49–R-60
Climate Zone 5B Attic Target
150+
Insulation Projects Completed
5 ZIPs
All of Longmont Covered
- Insured & Certified
- 100% Guarantee
- Free Estimates
- Locally Owned · Commerce City, CO
INSULATION COMPANY LONGMONT, CO
Insulation Built for Longmont, From Old Town Longmont to Prospect
Longmont was founded in 1871 as a planned farming colony and kept its historic grid. Old Town Longmont holds compact early-1900s Victorians and brick bungalows — often with almost no insulation to begin with — while newer neighborhoods like Prospect, St. Vrain Creek, and around McIntosh Lake were built to 1990s–2000s code minimums. Each era needs a different fix.
Sitting in Boulder County on the St. Vrain floodplain near the foothills, Longmont also sees strong Front Range wind, hard freeze-thaw swings, and the flash-flood and hail risk the St. Vrain corridor knows. A tight, well-insulated envelope is about comfort, efficiency, and resilience all at once.
Colorado sits in IECC Climate Zone 5B, which calls for R-49 to R-60 in the attic. Many older Longmont homes we inspect measure R-19 or less — and the oldest measure close to zero. Grizzly handles every service on this page for homeowners across 80501.
R-49+
The attic standard Longmont's climate calls for
TRUSTED PRODUCTS & PARTNERS
The Brands Behind Every Grizzly Install
We don’t install mystery material. Every Longmont project uses products from the industry’s most trusted manufacturers.
ALL INSULATION SERVICES
All Longmont Insulation Services, Grizzly
Click any service below for the dedicated Longmont page with full details, process, and neighborhood context:
Blown-in and batt upgrades to R-49–R-60 — from near-zero Old Town Longmont cottages to code-minimum Prospect homes. Most attics done in a day.
Closed-cell air-barrier foam for rim joists, additions, and the wind-exposed assemblies of Longmont’s older and newer homes alike.
Sealing the ceiling plane against Front Range wind before insulation — because in a leaky early-1900s cottage, air sealing is where the savings start.
HEPA-filtered removal of old, settled, or rodent-soiled material — clean deck, healthier air, disposal handled, ready for a proper reset.
Moisture-smart crawl space insulation and encapsulation for Longmont’s older cottages and St. Vrain Creek-corridor foundations.
EPA-registered TAP® borate insulation adds thermal performance and rodent deterrence in one install — built for open-space-adjacent Longmont homes.
Spray foam and fiberglass systems for Old Town Longmont’s Main Street storefronts, offices, and light-industrial space — off-hours, on schedule.
Not Sure What You Need?
Free home assessment across Longmont. We measure what your home has today and tell you exactly what it needs — no pressure.
WHY LOCAL EXPERTISE MATTERS
Longmont's Insulation Challenges
Three local realities shape how we quote, prep, and install every Longmont job — from Victorians and brick bungalows to open-space wildlife.
From Older Homes to New Subdivisions
Longmont’s homes span the early-1900s to today. Old Town Longmont’s Victorians and brick bungalows often have empty wall cavities and next to no attic insulation; the 1990s–2000s builds in Prospect and St. Vrain Creek carry code-minimum R-19. Each needs its own fix — dense-pack, top-off, or a full removal and reset.
Front Range Climate Extremes
Longmont sits on the St. Vrain floodplain near the foothills, where temperatures swing sharply and Front Range wind pushes cold air through every gap. Freeze-thaw cycling works openings loose around can lights, flues, and framing. Insulation without air sealing simply can’t keep up here.
Open Space = Rodent Pressure
St. Vrain Creek, McIntosh Lake, and the open space around Longmont funnel mice toward warm attics every fall. Rodent-soiled insulation loses R-value and hurts air quality. We handle removal, exclusion, and borate-treated pest-control insulation in-house.
150+
Projects Completed
10 mi
From Our Shop to Longmont
TAP®
Pest-Control Insulation Partner
EPA
Registered Borate Products
WHERE WE WORK
Longmont Neighborhoods We Serve
Grizzly serves every Longmont neighborhood and ZIP code (80501). Here’s how we typically approach insulation across the area:
ZIP codes covered: 80002 80003 80004 80005 80007
OUR PROCESS
How Grizzly Insulation Works in Longmont
Every Longmont project follows the same transparent path, from first call to final walkthrough, with financing made simple.
Free Home Assessment
We visit your Longmont home, measure existing insulation depth, map air leakage, and check for moisture or rodents. No charge, no obligation.
Clear, Itemized Quote
A detailed written quote with every line item priced and explained in plain English. No mystery numbers, no pressure.
Pick Your Plan
Pay up front or choose a monthly payment option that fits your budget. Apply in seconds, decisions are fast.
Professional Installation
Our crew air-seals, cleans, and insulates — most Longmont attics in 1–2 days — and hauls away every scrap of debris.
SAVE ON YOUR PROJECT
Longmont Insulation Rebates & Incentives
Most Longmont homes are served by Xcel Energy, and qualifying insulation and air-sealing upgrades can earn meaningful rebates — plus Boulder County efficiency programs. We handle the paperwork so your project qualifies.
Xcel Energy Rebates
Rebates available for qualifying insulation and air-sealing upgrades in Xcel service territory, which covers Longmont.
Federal 25C Tax Credit
30% of qualifying insulation project costs, up to $1,200 per year, under the Inflation Reduction Act.
Flexible Financing
Monthly payment plans so you can fix the attic now and pay over time, apply in seconds by text or link.
REVIEWS
What Homeowners Say About Grizzly
★ ★ ★ ★ ★
We kept hearing scratching in the attic every October, and the upstairs bedrooms never held heat. Grizzly’s crew vacuumed out sixty years of filthy insulation, sealed the entry gaps, and blew in the pest-control insulation, all in one day. Two winters later: no mice, warmer bedrooms, and our January Xcel bill dropped noticeably.
S
Sarah M.
Homeowner · Old Town Longmont Longmont · Removal + Pest-Control Insulation
★ ★ ★ ★ ★
“Our Old Town Longmont cottage had almost no insulation and a furnace that never caught up. Grizzly dense-packed the walls, air-sealed the attic, and brought it to R-49. Warm for the first time in years — and the bills dropped fast.”
D
David R.
Homeowner · McIntosh Lake, Longmont · Air Sealing + Attic Insulation
INSULATION LONGMONT
Frequently Asked Questions
Common questions about insulation in Longmont, answered straight.
Longmont is in Climate Zone 5B, where attics should carry R-49 to R-60 — roughly 16–20 inches of blown-in insulation. Old Town Longmont cottages often measure near zero; even 1990s Prospect homes measure R-19 or less. A free assessment shows exactly where you stand.
Almost always — the Victorians and brick bungalows have the most to gain because they started with so little. We often dense-pack the empty walls and air-seal first, then top the attic to R-49+. Degraded or rodent-soiled material comes out before new goes in.
Yes, in-house. St. Vrain Creek, McIntosh Lake, and Longmont’s open space put homes near steady rodent pressure. We remove soiled insulation with HEPA vacuums, seal the entry points, and install borate insulation that resists nesting.
They solve different problems. Blown-in cellulose is the cost-effective choice for open attic floors where R-49+ is the target. Spray foam delivers the highest R-value per inch and doubles as an air barrier, ideal for rim joists, crawl spaces, and garages. Many Longmont projects combine both.
Often, yes. Longmont is in Xcel Energy territory, and qualifying insulation and air-sealing work can earn utility rebates, plus the federal 25C tax credit covers 30% of qualifying costs up to $1,200/year. Programs change, so we confirm current eligibility during your free estimate and help with documentation.
Most single-family projects finish in 1–2 days. An attic top-off with air sealing on a typical Longmont ranch is often a single day. Whole-home projects touching the crawl space and rim joists may run two full days. You get a clear timeline with your quote, and we stick to it.
All of them, Old Town Longmont to Prospect, ZIP codes 80002, 80003, 80004, 80005, and 80007. Our crew is based in Commerce City, about 20 minutes away via I-76, and we offer free estimates across the entire city and Jefferson County.
EVERY COMMUNITY WE SERVE
Insulation Services Across the Front Range
Grizzly serves the entire Denver metro from our Commerce City base. Click your city for local details:
GET AN ESTIMATE
Schedule Your Free Longmont Home Insulation Assessment → No Pressure, Written Quote
We measure your current insulation, identify your biggest energy losses, and give you a clear, honest recommendation — warmer rooms, lower bills, and no uninvited critters in the walls.
- (303) 854-6221 · Mon–Sat 8 AM–5 PM · Sun by appointment
- info@grizzlyinsulationco.com, we reply fast, usually same day
- 7140 Ivy St Unit B, Commerce City, CO 80022, 10 miles from Longmont
Insured & Certified · 100% Guarantee · Locally Owned & Operated
Serving Longmont & Boulder County
7140 Ivy St Unit B, Commerce City, CO 80022 — fast dispatch across Longmont & Boulder County.