Custom Window & Door Replacement & Installation in Longmont, CO
From design to installation, we craft custom replacement windows and doors to ensure a fit for your Longmont home.
★★★★★ 400+ Google Reviews | Serving Longmont Since 2003
Longmont’s Leader in Windows & Doors
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Your Hometown Replacement Window Team in Longmont, CO
Offering top-quality exterior solutions and replacement windows in Longmont, CO, to enhance your home’s comfort, style and everyday life.
Window & Door Upgrades for Longmont’s Front Range Homes
Longmont offers every season in a single week. Window World installs energy-efficient replacement windows and doors built to help keep your home comfortable no matter the weather, with professional installation to back them up. Reach out to our local team for a free estimate.
Replacement Window Styles We Install in Longmont, CO
Outfit your Longmont, CO home in Prospect New Town with products you’ll adore at unbeatable values.
Energy Efficient Windows in Longmont, CO Homes
Because Prospect New Town in Longmont, CO sits around 4,984 feet, there’s less atmosphere to soften the sun’s UV. Every window we install includes Low-E glass that helps block it, protecting your floors, furniture and drapes.
A cold morning, a warm afternoon and a freezing night can all happen in one Longmont, CO day. Our windows combine insulated frames with argon-filled glass to slow heat transfer and keep your home comfortable through every change.
Entry & Patio Door Replacements in Longmont, CO
Find products you’ll love for your Longmont home, at prices made for your family.
What Your Longmont Neighbors Are Saying
See Why Longmont Homeowners Choose Window World
The installers did an incredible job, and my new windows are stunning! I’d recommend them to anyone and everyone!
10 out of 5 stars! Window World showed up on time, finished the job in less than a day, and left my house cleaner than they found it.
Window World made the process so easy and the install was top notch. I can’t believe the difference it’s made inside and out!
The Local Leader
Neighborhoods We Serve in Longmont
Window World of Denver serves Longmont from the historic homes around Main Street and the east side to Prospect New Town and the newer neighborhoods near Union Reservoir. Upgrading your Longmont windows with energy-efficient replacements helps block winter wind off the plains and keeps summer heat out.
- Prospect New Town
- Southmoor Park
- Sunset
- Rainbow Ridge
Longmont, CO Window Replacement: Frequently Asked Questions
Find fast, helpful answers to the questions we hear most from Longmont homeowners.
Longmont Power & Communications customers can get $3.75 per square foot for ENERGY STAR version 6 (Northern) windows, up to $1,500, or $5.00 per square foot for version 7, up to $2,000, through Efficiency Works in 2026. The rebate only applies when the work is done by an Efficiency Works–listed provider, and Window World of Denver isn’t currently on that list, so confirm eligibility before you plan around it.
Yes. Longmont has more than 130 local landmarks, and changes to designated properties, explicitly including window and door replacement, need a Certificate of Appropriateness from the Historic Preservation Commission. Colorado’s historic tax credit can count eligible window work on landmarked homes.
Prospect New Town, begun in the mid-1990s, was Colorado’s first New Urbanist neighborhood, with distinctive, traditional-style architecture. Double-hung and casement windows in colors that match the home’s exterior keep that look intact. Check the neighborhood’s design guidelines before changing window styles.
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