Windows, Doors and Vinyl Siding Installers in Chelmsford MA 01824, 01863


  • Exterior Door Installation
  • Replacement Window Installation
  • Vinyl Siding Installation


Replacement Door Company Serves the Greater Chelmsford Area

For all your Front Doors Installed in Chelmsford MA Replacement Door Improvements, O’Sullivan Install is the best company to call. There are many reasons why homeowners want or need to replace the exterior doors on their home – to let in more light, aesthetics, security, etc.

We offer high quality replacement doors that are from the industry’s leading brands, such as Top of the Line ProVia, and much more.


We are able to handle the following types of installations:

  • Storm Door Installations
  • Patio Doors Installations
  • Interior Door Installations
  • Aluminum Exterior Door Installations
  • Fiberglass Exterior Door Replacements
  • Steel Exterior Door Installations
  • Wood-Clad Door Installations


We Make It Easy To Replace Your Doors

We here at O’Sullivan Installs have been replacing doors for more than two decades on New Hampshire and Massachusetts homes. You can rely on us to provide you with excellent replacement door product lines along with superior service and great installation.

You can fully expect that installing your next replacement door will be a smooth and easy process. We will take care of everything for you.


Call Today (978) 362-2396


Window Replacement and Installation in Massachusetts

No other New Window Replacement Services in Chelmsford MA company in Essex and Middlesex County can provide you with better installation or a better quality window than O’Sullivan Installs. Quality is our main emphasis, and always will be.

Whenever you hire us to have your replacement windows installed, you can be confident you have hired the best company who will do the job right the first time and takes great pride in all of the work that we do.


We can handle all of the following kinds of installations:

  • Bow Window Installations
  • Bay Window Installations
  • Casement Window Installations
  • Double Hung Installations
  • Lite Sliding Installations
  • Picture Window Installations
  • Sliding Window Installation


Prevent Weather from the Outdoors from Entering Inside

Replacement windows work as an effective barrier against outside weather. In addition, they provided an added level of protection against moisture to keep humidity and rain out. Windows also provide the home with protection from strong winds.

There are many companies that offer a number of different glass options to homeowners. The level of ultra-violet light is reduced by the Low-E glass. Two additional glass options are heat mirrors and gas fills. Insulation is increased by gas fills through filling the space that is in between glass panes with krypton and argon. With heat mirrors, a piece of heat film is added in between the two panes.

The film filters 99.4 percent of the UV rays out. A good option for areas with harsh weather conditions is composite window replacement. The exterior of these windows is made out of aluminum or weather-resistant vinyl. They are also water and air-tight.


Why does your house need to have insulated vinyl siding?

Are you searching for an affordable way ofVinyl Siding installations in Chelmsford MA improving the function and look of the exterior of your home? If so, you have come to the right place. Vinyl siding is the leading exterior cladding in the U.S., and when you consider that air leakage may account for 30% or more of the cooling and heating energy costs of a Massachusetts home, insulated vinyl siding offers a clear solution.

The purpose of insulated vinyl siding is to improve the curb appeal and stability of the siding, increase the wall system’s insulation value and reduce energy consumption. When it comes to external noise, insulated vinyl also acts as a noise barrier.


Durable Insulated Vinyl Siding

In contrast to conventional hollow siding, which may be damaged by things like flying baseballs, hail and rain, insulated vinyl siding provides impact resistance that is five times greater than hollowing siding offers. There are various colors that insulated vinyl is available in and requires no or little maintenance.

Compared to traditional siding, insulated vinyl siding provides better sound control properties and better weather performance. Insulated vinyl siding has a rigid foam backing that makes it possible for the material to lay down flat and provides a cleaner, straighter exterior.


Click here to see what our customers are saying about us

Installation went well. Had to wait a long time for the custom patio doors to be mfg. Quality of the doors is very good so far. Had a problem with the tempered glass thickness when installed. Tim spotted it right away. Had the doors replaced w thicker tempered glass @ N/C by ProVia. Both the thin and thick glass were within code but we wanted the thicker one.

Better safety. ||Finding doors took a lot of research. Many brands that had been highly rated, in the past, now had serious problems reported on line. Several had class action law suits for warranty non-compliance. Many horror stories. I thought ProVia had a better “current” reputation and warranty than many of the other larger companies. Time will tell.

Description of work:
Installation of doors.

• Overall A
• Price B
• Quality A
• Responsiveness A
• Punctuality B
• Professionalism A

Category: Doors
• Services Performed: Yes
• Hire Again: Yes


After reading some of the reviews on Angie’s List, I contacted O’Sullivan Installs for an estimate to replace 7 Anderson crank windows with double hung windows and to side my home. I met with George, the salesman for the company, he was very professional, patient, answering all my questions, and those of my curious 9yr old child! He explained the difference in the two styles of siding O’Sullivan Installs uses and demonstrated the benefits of the windows that they carry.

He gave me a written estimate that was more than I anticipated, but I was impressed with the reviews and the information George provided, so I gave him the deposit check after I had picked out the color and style of siding. Within a short time, the owner of the company Tim O’Sullivan came to my home to go over measurements and make sure all the information I had received was correct. He assured me that he would be in contact soon regarding an installation date. Due to nasty weather, the install did get delayed, however, as soon as the weather cleared a dumpster was delivered to my driveway, after receiving a text from Tim to ensure that the timing was appropriate.

I did not realize the scope of the job until I came home one day to find my house with 7 new wonderful windows that brought so much light into my dark family room and my house partially wrapped in Tyvek and the dumpster was full of the shingles, clapboards, and various materials that had been the outside of my home. I did not remember until then that George had mentioned that they go down to the bare wood on the house and wrap it to ensure a good strong moisture barrier. In short order, the rest of my house was Tyveked and gradually the new siding was installed. There were several workers and all were very polite and professional.

At one point they had to be inside my house to install the windows and I felt perfectly comfortable with them being inside. They even were able to corral my two dogs when they escaped the room they were in and get them secured in another room so they did not take advantage of the open door to explore the neighborhood. The most time consuming job the men did was the installation of the trim. Tim O’Sullivan is a dream contractor-he is a perfectionist and will make the workers take trim pieces down and reinstall them until he is satisfied. He even insisted on replacing the sashes on most of my new windows because he found that the grids were not straight.

I examined these grids themselves and even with Tim pointing it out, I could not find the inconsistencies he did. However if he wanted to replace them, I was okay with that and once again, when the time came for that work to be done, he was certain to make sure the time was convenient for me. Overall I am extremely pleased with the work done on my home and would and have recommend O’Sullivan Installs. Tim O’Sullivan is very easy to work with, yet is a perfectionist, which I think is a perfect combination in a contractor.

Several neighbors commented on the improvement in my home from the day the windows were installed, some neighbors who I had not personally known. It has made an enormous improvement in both the outside of my home and the new windows and insulated siding have much improved the temperature and comfort of the family room and it is like having a brand new room! To be perfectly honest, the estimate that initially seemed a bit high to me ended up being extremely reasonable given the quality of the work, professionalism of the workers, and perfectionist of the contractor.

Description of work:
Complete house siding including trim and installation of 7 large double hung windows.

• Overall A
• Price A
• Quality A
• Responsiveness A
• Punctuality A
• Professionalism A

Category: Siding, Windows
• Services Performed: Yes
• Hire Again: Yes


EXCELLENT EXCELLENT EXCELLENT. I can’t say enough positive things about my experience with O’Sullivan Installs. My calls were actually returned (unlike most contractors out there!!), the work was delayed a bit due to storms but when they were able to finally get out, they worked ALL DAY (in the cold I might add!) with meticulous attention to detail and clean up.

They respected our home laying down plastic around all work areas (George, the person who comes out, measures, and gives you a quote) even took his shoes off coming in the house!! They’re all very courteous people. Tim, the owner, comes out to the house before the job even begins to inspect the job site reviewing the quote with you, and while the job is on-going he also comes out (although he really didn’t have to, his workers were terrific).

While installing windows along a bump out bay, it was discovered we had a lot of rot under the siding surrounding the bay – we knew we had issues there, but never addressed it properly. Tim came out, inspected the damage and referred us to a contractor who was out the next day to look at it and the following week to remove siding, replace the rot, and improve insulation. Reside the house and fix the deck and they too (North Tewksbury Construction) did an outstanding job (we ended up talking with them about a 3 season porch that we are going to install and will give them our business too).
I have no hesitation giving O’Sullivan Installs the highest rating on all counts – from beginning, answering questions on the quality of the windows, install procedure, etc., through to the end. We love the windows (Soft-Lite) and Pro Via slider) and have noticed a big difference in the house already. No more drafts and definitely much warmer. Go with them, you won’t be disappointed.

Description of work:
Replace all windows in hours/install new slider/garden window in kitchen/replace some additional trim around the house

• Overall A
• Price A
• Quality A
• Responsiveness A
• Punctuality A
• Professionalism A

Category: Windows, Carpentry – Woodworking, Doors
• Services Performed: Yes
• Hire Again: Yes


Free, No-Obligation Consultations in Massachusetts

Get a Free Exterior Door Consultation Today!


Any Questions?
Call Us (978) 362-2396


Chelmsford, MA 01824, 01863


We are also serving:
Chelmsford, Lowell, Tewksbury, Billerica, Carlisle, Westford and Tyngsboro