Several years ago in 2015, KCSI did a great job replacing the siding on my single-family home, detailing all of the window trim, and replacing a sliding glass door with a patio French door. Recently, in 2025, I initiated a new home improvement project that would impact some of the siding on the rear of the house. Rather than relying on a general contractor to replace the siding, along with some other repairs, I reached back out to KCSI. Once again KCSI came through and did a quality job. They were flexible with scheduling, attentive to details, and the results look great. I clearly made the right choice years ago when I selected KCSI, and I’m happy as a repeat client.
Jeff Seguin
Aug 2025
We recently hired KCSI Construction Inc to replace the vinyl siding on the side of our home. John Knowlan was very knowledgeable and easy to work with. Excellent communication throughout the project. His crew was hardworking and professional, and it was clear that they paid attention to the details. When the old siding was removed, we knew there would be problems that needed to be addressed. John proposed new sheathing to provide a more solid foundation, and the price was reasonable. If you are looking for a professional, detail oriented construction company that KNOWS THEIR TRADE - you should strongly consider going with KCSI Construction.
Rozita Ezazi
Aug 2025
John and his Team did a wonderful Job replacing the entire Windows in our townhouse . Quality Products, Punctuality, attention to details .They provide it all. John is very helpful and kind, I highly recommend KCSI . Their entire process was perfect. Thank you KCSI .
John D'Emidio
Jul 2025
I highly recommend KCSI Construction company...A storm destroyed the vent in the siding near the roof and I did not know what to do, nor where to begin looking for someone who could help me. Through word of mouth, I contacted John and his company. His prompt reply was very much appreciated. Within a couple of days they rebuilt the hole so a new vent could be put in. I was scared of wild animals getting into my roof area so the quick response prevented that and was just great. Thank you!! Susan D'Emidio
Mark Sullivan
Jul 2025
KCSI did a fantastic job in replacing the roof on our single-family home in Arlington in May 2025. Co-owner John Knowlan and his experienced team went above and beyond in executing the project with good communication throughout, attention to details, and thorough final cleanup. It’s not a surprise that John and his team did such a great job since they had worked on our home a dozen years ago when they did a phenomenal job installing new siding and trim, gutters and down spouts, and a new patio door. We were very lucky then to find a company we could trust and so happy to do business with them again.
Taner Durusu
Jan 2025
John and his team did a fantastic job on repairing our box bay bump out window. Not only was the work of high quality, John made the project scoping and estimating process exceedingly easy. He gave us lots of advice and suggestions without being pushy or over-selling. Can’t recommend them enough.
Darrin Speck
Oct 2024
John and his team replaced all the windows as part of a larger house renovation and I couldn't be happier. Very easy to work with and top quality. Will definitely use again.
Robert Lauder
Oct 2024
After we had a wasp infestation under our siding we called in an exterminator to resolve the issue. They had to lift siding to get to the wasps and really mangled the siding. Called in John to see if it could be repaired or have to do the whole house (old house, aluminum siding). John took a look and said he could repair the siding and you’ll never know it happened. He was right, looks great. I fully believe any other contractor would have said to replace the siding.
Corinne Abbott
Sep 2024
John Knowlan is the best contractor we have worked with. Very knowledgeable, thinks ahead, listens to your preferences then gently guides you to the best choices, products are high quality, price is great, seeks deals for you where he can, always offers to return if there are any problems, very responsive. His workers stay with him a long time - a very good sign.
Laurie Smith
May 2024
This company is terrific. Their workmanship is great. The entire process from estimate to completion was easy with no problems. We had some scheduling issues because of permitting but KCSI was willing to accommodate our needs. I highly recommend them.
TRogers
Several years ago in 2015, KCSI did a great job replacing the siding on my single-family home, detailing all of the window trim, and replacing a sliding glass door with a patio French door. Recently, in 2025, I initiated a new home improvement project that would impact some of the siding on the rear of the house. Rather than relying on a general contractor to replace the siding, along with some other repairs, I reached back out to KCSI. Once again KCSI came through and did a quality job. They were flexible with scheduling, attentive to details, and the results look great. I clearly made the right choice years ago when I selected KCSI, and I’m happy as a repeat client.
Jeff Seguin
We recently hired KCSI Construction Inc to replace the vinyl siding on the side of our home. John Knowlan was very knowledgeable and easy to work with. Excellent communication throughout the project. His crew was hardworking and professional, and it was clear that they paid attention to the details. When the old siding was removed, we knew there would be problems that needed to be addressed. John proposed new sheathing to provide a more solid foundation, and the price was reasonable.
If you are looking for a professional, detail oriented construction company that KNOWS THEIR TRADE - you should strongly consider going with KCSI Construction.
Rozita Ezazi
John and his Team did a wonderful Job replacing the entire Windows in our townhouse . Quality Products, Punctuality, attention to details .They provide it all. John is very helpful and kind, I highly recommend KCSI . Their entire process was perfect. Thank you KCSI .
John D'Emidio
I highly recommend KCSI Construction company...A storm destroyed the vent in the siding near the roof and I did not know what to do, nor where to begin looking for someone who could help me. Through word of mouth, I contacted John and his company. His prompt reply was very much appreciated. Within a couple of days they rebuilt the hole so a new vent could be put in. I was scared of wild animals getting into my roof area so the quick response prevented that and was just great. Thank you!! Susan D'Emidio
Mark Sullivan
KCSI did a fantastic job in replacing the roof on our single-family home in Arlington in May 2025. Co-owner John Knowlan and his experienced team went above and beyond in executing the project with good communication throughout, attention to details, and thorough final cleanup. It’s not a surprise that John and his team did such a great job since they had worked on our home a dozen years ago when they did a phenomenal job installing new siding and trim, gutters and down spouts, and a new patio door. We were very lucky then to find a company we could trust and so happy to do business with them again.
Taner Durusu
John and his team did a fantastic job on repairing our box bay bump out window. Not only was the work of high quality, John made the project scoping and estimating process exceedingly easy. He gave us lots of advice and suggestions without being pushy or over-selling. Can’t recommend them enough.
Darrin Speck
John and his team replaced all the windows as part of a larger house renovation and I couldn't be happier. Very easy to work with and top quality. Will definitely use again.
Robert Lauder
After we had a wasp infestation under our siding we called in an exterminator to resolve the issue. They had to lift siding to get to the wasps and really mangled the siding. Called in John to see if it could be repaired or have to do the whole house (old house, aluminum siding). John took a look and said he could repair the siding and you’ll never know it happened. He was right, looks great. I fully believe any other contractor would have said to replace the siding.
Corinne Abbott
John Knowlan is the best contractor we have worked with. Very knowledgeable, thinks ahead, listens to your preferences then gently guides you to the best choices, products are high quality, price is great, seeks deals for you where he can, always offers to return if there are any problems, very responsive. His workers stay with him a long time - a very good sign.
Laurie Smith
This company is terrific. Their workmanship is great. The entire process from estimate to completion was easy with no problems.
We had some scheduling issues because of permitting but KCSI was willing to accommodate our needs. I highly recommend them.