New windows.
Lasting comfort.
Energy-efficient replacement windows and doors — measured, built, and installed by K Windows & Doors' own certified crews you can count on.
Every window and door, handled by one team
Replacement Windows
Double-hung, casement, bay & bow — energy-efficient frames that cut drafts and lower bills.
Learn more →Entry & Patio Doors
Steel, fiberglass, and sliding glass doors that seal tight and lift your home's curb appeal.
Learn more →Repair & Service
Glass replacement, seal failures, hardware, and screens — diagnosed and fixed fast.
Learn more →New Construction
Builder packages from standard to high-performance for additions and new homes.
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The difference is in who shows up — and what they leave behind.
Four steps, no surprises
Free consultation
In-home or virtual. We listen, measure, and quote — with no pressure.
Custom measure & order
Precise field measurements. Windows built to your exact openings.
Clean installation
Our certified crews protect your home and haul away the old units.
Built to last
Quality products and careful installation — backed by our family's craftsmanship since 1957 and thousands of completed projects.
Find the right window for every room
Recent projects
Glen Ellyn Door Conversion
Arched window to full glass door conversion in Glen Ellyn.
Before
After
Before
“KWindows made what I thought was going to be an incredibly challenging installation look simple. My house is over 100 years old, and nothing is standard about it. They arrived on time, completed the work quickly, and kept a clean workspace. Would recommend!”
“We have 20 large nonstandard windows and a brick house… He is a true craftsman, reliable and does not overbook. Your job will be completed in time and you will LOVE your new windows. Your home will be quieter and hold heat and cool infinitely better.”
"He was wonderful. Explained what he was doing and was focused on what we asked and needed. I would highly recommend!!"
"Greg was a smart friendly guy who really knows what he is doing. I had been having door issues for years and in less than an hour Greg made them go away forever!!"
"Great installation! Look and operate perfect. Great on the clean up too!"
Ready for a clearer view?
Book a free, no-pressure in-home estimate. Most quotes take less than an hour — and there's never an obligation to buy.