Home Extensions & Additions on Long Island
Expand your living space with high-quality, code-compliant home extensions built by NJM’s licensed and experienced construction team. From single-room additions to full multi-level expansions, we deliver durable, seamless structures for homes across Nassau and Suffolk County.
Expert Residential Additions • Structural Integrity • Code-Compliant Builds
Professional Home Extensions Backed By Decades of Construction Experience
Whether you’re expanding your living room, adding new bedrooms, or building a larger kitchen, NJM Mechanical and Contracting provides reliable, high-quality extension construction throughout Long Island, NY. Our licensed and insured team brings over 33 years of experience to each project, ensuring safe, code-compliant, and long-lasting additions.
From foundation work and framing to roofing, insulation, and interior finishing, we deliver complete extension solutions that blend seamlessly with your home while improving functionality, space, and property value.
Expand your home with fully customized room additions designed for comfort, functionality, and seamless integration with your existing structure.
Increase your kitchen’s footprint with professionally built extensions that improve layout, storage, and modern usability.
Add a full second level or additional upper-floor rooms with code-compliant framing, roofing, and engineering for long-term stability.
Transform your garage into a finished living area, workspace, or guest room with proper insulation, flooring, electrical, and HVAC integration.
Create comfortable private living quarters complete with proper utilities, accessibility, and customized layouts for extended family.
Build functional and beautiful outdoor additions including covered patios, enclosed spaces, and seasonal living areas.
Expert Home Extensions Backed
by Over 33 Years of Experience
Why Choose NJM for Home Extensions & Additions
Expert extension construction backed by licensed professionals and decades of hands-on building experience.
Our team is fully licensed and insured to perform structural additions and major home expansion projects across Long Island.
We ensure all extensions are reinforced properly, aligned with existing load-bearing systems, and engineered for long-term safety.
Roofing, siding, flooring, and trim are carefully matched to create a cohesive, natural extension of your current home.
We handle plumbing, HVAC, and electrical integration with full adherence to Nassau and Suffolk County building regulations.
Decades of professional experience mean we install fixtures, piping, and full systems correctly the first time — with workmanship that lasts.
No hidden charges or surprise add-ons. You’ll receive a clear estimate outlining exactly what your installation includes.
Foundation & Structural Load Assessment
Ensuring the new extension is properly supported through reinforced foundations and accurate load distribution.
Insulation & Moisture Protection Review
Verifying insulation, vapor barriers, and weatherproofing for comfort and energy efficiency.
Roofline & Framing Inspection
Reviewing roof tie-ins, trusses, and framing connections for long-term structural integrity.
Exterior Weatherproofing & Flashing Checks
Ensuring siding, roofing, and flashing are installed correctly to prevent leaks and water damage.
Utility & Infrastructure Planning
Inspection of electrical, plumbing, and HVAC line extensions for safe, compliant integration.
Code Compliance & Permit Assistance
Support with building permits and adherence to Nassau and Suffolk County regulations.
Trusted Construction Expertise for Long Island Homes
Our Extension Safety & Structural Inspection Services Include:
NJM provides detailed evaluations, structural reviews, and compliance checks to ensure your home addition is safe, durable, and built to code.
Find Contracting Services Near You!
Service Area Links:
- Long Island
- Nassau County
- Suffolk County
What Our Long Island Clients Are Saying...
Kris
I couldn’t recommend Neil enough! From start to finish him and his team were professional, efficient and experienced. We had a job pulling up rocks and putting top soil down which I know can be a tedious job. We appreciate the work and look
Evelyn Powers
We had an ongoing issue with clogs. My daughter woke up to flooding in her bedroom from her toilet, which was not fun! This was our first time having NJM in our home. Neil was knowledgeable and gave us several options. we chose to have him use the camera to get to the root of the problem. He was able to pinpoint several issues and was able to fix clog and clean out the pipes. Neil and his crew were very professional,
Irene Cheung
I contacted NJM Mechanical because I didn’t have hot water anywhere in my house. Neil was able to diagnose the issue and get to work. My navien tankless water heater is only a year old and still under warranty. Instead of waiting on Navien to send the part so the issue can be corrected, Neil went out, found the part, purchased it,
William Lo
Great experience. Neil came out and took the time to explain everything thoroughly. He was able to fix all the errors on our Navien and have it back up and running. Following up a week later. Neil and Mike came out to redo the Navien system for proper instillation.
Unfortunatley, after there was a gas leak with our Navien system. Neil was able to get
James Farnworth
Neil from NJM was able to get my ac system up and running when others could not. He was honest with me right from the beginning and all costs were discussed before repairs began. Additionally, Neil spent time explaining to me how my system operates and the things I could do to help it run at peak performance. It was quite refreshing to experience a service technician who demonstrated the uppermost
Raul Chardon
Honest professional full of knowledge not BS. Takes pride in his craft and is a master of it.
Contact NJM Mechanical & Contracting For Plumbing Services
Need reliable plumbing solutions? Whether it's an emergency repair or routine maintenance, NJM Mechanical & Contracting is here to help. Our expert team, including a Licensed Master Plumber, has been solving plumbing issues for Long Island homeowners since 1991. From small leaks to major installations, we handle it all with professionalism and care.
Get in Touch Today!
Phone: (631) 587-0085
Email: njmcontracting@gmail.com
Service Area: Long Island,
Nassau County, Suffolk County
Don’t wait for small problems to turn into big ones. Contact NJM Mechanical & Contracting for trusted, professional plumbing services you can rely on.