Window Icon

Window replacements are usually not a priority for most people when they think about home improvement projects.


Door Icon

Door replacement offers one of the most effective and cost-wise ways to improve both the safety and the appearance of a home.


Siding Icon

It’s obvious new siding makes your house look great, but siding is about more than aesthetics; it’s critical to your home’s structural integrity.

Exterior Remodeling and Replacement Windows in Billerica, Massachusetts from O'Sullivan Installs

Remodeling Your Home in the Middlesex County, Massachusetts and Surrounding Areas the Right Way with Quality Windows, Doors, Vinyl Siding and James Hardie Siding Installation Solutions.

With over 20 years experience serving the greater Billerica, Massachusetts area, O’Sullivan Installs is the premier choice for your home improvement project. Specializing in replacement windows, siding installation and exterior doors, we offer a wide range of industry recognized products and award winning installation, all at surprisingly reasonable pricing. At O’Sullivan Installs we don’t dictate how your home renovation project will go, we work with you to plan the best options and scheduling to work within your family life and budget.

Plus, with our ultimate package of windows, doors, and siding, our energy-efficient services are easy on your wallet and the environment!

Don't Just Take Our Word For it Though!

Here's what one of our happy customers had to say about our work:

"We had a large project to do. We wanted to reside our whole house, including all the trim. They ran into various issues & always communicated with us exactly what was going on. Guess the thing that impressed me most was the job cost what they said it would cost, even though we ran into some wood rot issues, that could have cost us thousands more to repair. They ate that cost, providing an excellent solution. Can't say enough about the great job they did. We constantly get compliments from the neighbors on the great job they did. they kept the site as clean as possible, always tidying up before going home. I would recommend O'Sullivan Installs in a heartbeat. Tim is a super guy as are all his team members."

~ Jim H. of Acton, MA

Dave Seymour Recommends O'Sullivan Installs

Dave Seymour of the hit show 'Flipping Boston' shows off the siding he had installed on his own home by O'Sullivan Installs.

10 Year Exterior Remodeling Workmanship Guarantee

o'sullivan installs 10 year guarantee badgeMost remodeling and home improvement companies would NEVER guarantee their work for more than 1-Year (the minimum allowed by law). Why? Because they just aren't confident in their services to guarantee this in writing beyond 1-Year. NOT O'Sullivan Installs! We believe you deserve the best service for your investment, so we hold our workmanship to a higher standard. We are so confident in our services and the products we use in your home that we offer an unprecedented 10-Year Workmanship Guarantee.

We stand behind what we install and want you to be a client for life. Most of our clients end up doing multiple remodeling projects with us over the course of their lives. This is a direct testament to the fact that we won’t nickel and dime you if something goes wrong. We strive to be 100% perfect on every project but if we do make a mistake or you are not happy with something, please let us know and we will be out to your house within 24-48 hours.

Contact Us to Get a Free In Home Consultation Today!


Easy Ways To Fix What's Broken

Which Replacement Product Is Right For You?

Existing product replacements allow you to get the latest in performance features while preserving the original frame, exterior trim and look.

Full replacement products mirror new construction installations. The entire existing product is removed, resulting in weather tightness and often greater function.

Superior Customer Service

We believe that a satisfied customer is the best advertising available to any business.

Our product innovation and personnel training guarantee our customers the finest quality product and workmanship at an equitable price. Serving the Boston area with superior products and outstanding customer service.