Welcome to Nisi:

Your Ultimate Destination for
Home Improvement Roofing Solutions!

Protecting HOMES

SINCE 2004

Proudly Serving Nassau

and Suffolk Counties in Long Island NY.

WHAT OUR

CUSTOMERS

ARE SAYING:

ExcellentGoogle star 1Google star 2Google star 3Google star 4Google star 55.0285 reviews
5.0Google star 1Google star 2Google star 3Google star 4Google star 5
Excellent285 reviews
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Natum Sanchez profile picture
Natum Sanchez
2 November 2026
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Hi Marvin, Maggie and I wanted to personally thank you and your entire team for the excellent work repairing the roof and gutters and making the exterior of our home look immaculate. Your team was truly professional from start to finish, and we couldn't be happier with the results. We will definitely recommend you and your company to anyone in need of home improvements. Once again, we can't thank you enough for your hard work, attention to detail, and professionalism. Muchísimas gracias! Best regards, Nate & Maggie
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Urszula Zych profile picture
Urszula Zych
23 October 2026
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Outstanding Roofing and Gutter Installation! I highly recommend NISI Home Improvement, Inc. for their exceptional work on our complete roof and gutter replacement. From start to finish, the entire experience was professional, organized, and stress-free. A special thank you to Marvin Guevara for his outstanding customer service, professionalism, honesty, and attention to detail. He took the time to explain everything, answer all our questions, and make sure we were completely satisfied. The crew did an amazing job installing our new Owens Corning roof, replacing the skylight, and upgrading our gutters and downspouts. Their workmanship was excellent, and they treated our property with care, leaving everything clean and spotless. The quality of work exceeded our expectations, and our home looks beautiful! If you’re looking for a reliable, knowledgeable, and professional roofing company, NISI Home Improvement is an excellent choice. Thank you, Marvin and the entire NISI team, for a job exceptionally well done! Highly recommended!
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Michael Tucciarone profile picture
Michael Tucciarone
23 October 2026
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Siding repaired for new electrical meter installation. Great job
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Marco Antonetti profile picture
Marco Antonetti
21 October 2026
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⭐⭐⭐⭐⭐ NISI Home Improvement — Outstanding Work, Exceptional Service, and Unmatched Quality! I couldn’t be happier with the work NISI Home Improvement did on my home. They installed new windows, siding, a roof, and a beautiful new front door. They also built out the soffits and overhang for a new porch, and the finished result is absolutely amazing! From start to finish, the entire experience was outstanding. The team was extremely responsive, thorough, and professional throughout the entire process. Every step of the way, they took the time to explain my options, answer my questions, and guide me toward making the best possible decisions for my home. The quality of their workmanship was exceptional, and it was clear that they take tremendous pride in what they do. What really sets NISI Home Improvement apart is their integrity and attention to detail. They don’t cut corners, they don’t nickel-and-dime you, and they consistently go above and beyond to make sure everything is done right. They genuinely care about the quality of their work and making sure their customers are happy. Finding a contractor you can trust to deliver outstanding results, communicate effectively, and treat your home as if it were their own is not easy. NISI Home Improvement exceeded my expectations in every way. I would recommend NISI Home Improvement without hesitation to anyone looking to improve their home. If you don’t use this company, you’re making a big mistake! I couldn’t be happier with the results and would absolutely use them again.
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Rebecca Baffi profile picture
Rebecca Baffi
15 October 2026
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+0
Rey was the best to deal with. They did such a great job.
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Dan Hunt profile picture
Dan Hunt
3 October 2026
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Awesome Job! Done on time. I liked to deal with Marvin.
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Ashok Sharma profile picture
Ashok Sharma
30 September 2026
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Job was done on, I am very pleased with their work.
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Jacqueline Charlton profile picture
Jacqueline Charlton
29 September 2026
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NISI does excellent work, The workers are efficient and professional, This is the third time I have used this company. I will always recommend.
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Michael O'Leary profile picture
Michael O'Leary
28 September 2026
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I hired NISI to replace my roof last fall. Nelson came out and quickly provided me with a detailed estimate of the project. The estimate was less than other companies had provided Nelson was great to work with and was on the job site from start to finish. I can’t say enough of how easy Nelson was to work with, answering all questions and explaining in detail the work involved. They even encountered a broken vent pipe and were able to secure a plumber to complete the work immediately. This was no small matter and was handled quickly and efficiently The job was completed within the timeframe presented and my property was thoroughly cleaned afterwards I cannot say enough how pleased I was with hiring NISI to replace my roof I can highly recommend NISI for roofing but I would expect that their same high level of professionalism would apply to any of the services they provide
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Aimee Hsu profile picture
Aimee Hsu
23 September 2026
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Easy, straightforward process. Rey and his guys were great to work with. Respectful and did a great job fixing our leaking skylight. Would definitely use them again.

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