Trusted Window and Door Installation in Lebanon, NH

Historic homes and newer construction each need a different approach. A1 Pro handles both, with permits pulled on every job and a 50-year manufacturer’s warranty on installed materials.

Window and Door Installation for Lebanon Homes

A1 Pro installs and replaces windows and doors across the Upper Valley, from historic neighborhoods to newer builds near West Lebanon:

Full-frame window replacement backed by a 50-year manufacturer warranty.
Entry, patio, and interior door installation.
Retrofits that respect the character of older homes.
Energy-efficient upgrades that lower heating and cooling costs.

One estimate, one price. No surprises.

Window Installation Service in Lebanon, NH

Door Installation for Upper Valley Homes

See Recent Installations

Ready for Windows That Actually Keep the Cold Out?

Every winter you sit through with drafty windows is money lost to heating bills. A free estimate tells you exactly where you stand, with no obligation.

Signs It's Time for New Windows or Doors

Not sure whether to repair or replace? Homeowners typically call us when they notice:

Drafts near the frame even with everything closed.
Windows or doors that stick, warp, or won’t latch.
Condensation or fog trapped between glass panes.
Rising heating bills with no clear explanation.
Wood rot or soft spots around the frame.

A free inspection will tell you whether repair or replacement makes more sense for your home.

Serving Lebanon and the Upper Valley

The A1 Pro Difference

A1 Pro pulls a permit on every job, backs every installation with a 10-year labor warranty, and gives Lebanon homeowners honest, upfront pricing, no hard sell, no surprises.

10-Year Labor Warranty

Permits Pulled on Every Job

Free, No-Pressure Estimates

What Lebanon Homeowners Are Saying

Brandon Stachulski

Exceptional craftsmanship and outstanding quality. Despite unexpected challenges like exposing rot, they adapted quickly and delivered within the original timeline. Special thanks to Ed in sales, owner Luis, and the entire team on-site.

Casey G.

A1 Professional came quickly to give me a quote for a large deck. Gave me a great price and started on time. They took care of permits and was here every day until they finished. They are the best I’ve ever worked with!!

Nicolas Kensington

Great design and build — new deck, clearing trees and a pathway to my lake. Quality exceeded expectations, completion time was impressive and the price was reasonable. Will use them again.

Cheryl Sealey

A1 did a wonderful job, quoted and done in 1 day. My garage roof looks great too. I highly recommend this company. Thank you for your professionalism. — C Sealey

Mary Brown

Great guys to work with. My chimney replacement looks great. Company is very responsive, got back to me with an estimate within the week after inquiring about the leak around my chimney.

Leslie Badore

A1 Professional did a great job installing siding on our home. The crew is neat, professional and hard-working. Everyone is polite and easy to work with. We are so pleased and will be happy to recommend them in the future. Well done!

Get Your Free Lebanon Estimate Today

One visit, one honest number, no obligation. Military and senior discounts available.

Frequently Asked Questions

How much does door installation cost in Lebanon, NH?

Cost depends on the door type, size, and material. A1 Pro gives you an exact number on the spot during a free estimate, not a rough figure over the phone.

Do I need to be home during window installation?

It helps, but it’s not required for most installations. A1 Pro walks you through the schedule ahead of time and lets you know if your presence is needed for any part of the job.

Is it better to replace all my windows at once or one at a time?

Replacing all your windows together usually costs less per window and gets the job done in one visit. A1 Pro can also phase the work for homeowners who prefer to spread out the investment.

What kind of warranty comes with window installation?

Every window and door installation from A1 Pro is backed by a 5-year transferable craftsmanship warranty plus a 50-year manufacturer warranty on materials, both delivered in writing before the job starts.