General Contracting Services on Long Island, NY
From residential renovations to commercial construction, NJM delivers licensed, professional contracting services across Nassau and Suffolk County. With decades of hands-on experience, we handle structural work, utility installation, site preparation, and full-service construction with precision and reliability.
Available for Residential & Commercial Contracting Projects
Trusted Contracting Experts for Nassau and Suffolk County
Licensed and experienced contractors with over 33 years of expertise delivering safe, reliable, and code-compliant construction for homes and businesses across Long Island.
NJM builds custom dormers that expand living space, increase home value, and improve natural light — completed with precise structural framing and code-compliant construction.
From room expansions to full home additions, our licensed contracting team delivers seamless, durable extensions that blend perfectly with your existing structure.
Professional installation of energy-efficient windows designed to improve insulation, reduce drafts, and enhance the appearance of your home or business.
Secure, properly fitted door installations including entry doors, interior doors, sliding doors, and commercial-grade options — all installed with long-lasting durability.
Full-service kitchen remodeling including cabinetry, flooring, plumbing, lighting, appliances, and structural work — built to your specifications with exceptional craftsmanship.
From layout changes to complete bathroom rebuilds, NJM delivers high-quality tiling, plumbing, fixtures, and finishes to create modern, functional bathroom spaces.
Expert Contracting Solutions Backed
by Over 33 Years of Experience
Why Long Island Property Owners Trust NJM for Contracting Services
With decades of field expertise, certified professionals, and a reputation for quality workmanship, NJM delivers reliable contracting services for any size project.
NJM is fully licensed and insured, ensuring every contracting project meets local Long Island safety and building requirements.
Our team includes specialists experienced in excavation, structural framing, concrete work, and full-scale renovations.
All projects are completed to Nassau and Suffolk County building code standards for safety, durability, and compliance.
We coordinate every phase—from inspection to completion—to keep your project efficient, organized, and on schedule.
Serving Long Island since 1991 with proven reliability and technical expertise.
Upfront quotes, no hidden fees, and clear explanations for every service.
Structural Integrity Inspections
Assessment of framing, load-bearing components, foundations, and structural systems for safety and stability.
Concrete & Masonry Evaluation
Review of concrete curing, blockwork, footings, and foundational integrity to ensure long-term durability.
Excavation & Site Safety Review
Evaluations for trench safety, soil stability, drainage, and grading to ensure proper site conditions before construction.
Permit & Code Compliance Checks
Ensuring all plumbing shut-off valves function properly in the event of leaks or system failures.
Utility System Compliance
Inspection of installed piping, mechanical lines, and infrastructure to meet local utility standards and code requirements.
Pre-Construction Planning Assessments
Thorough evaluations of site logistics, safety risks, and material readiness before work begins.
Trusted Contracting Expertise for Long Island Homes & Businesses
Our Construction Safety & Inspection Services Include:
NJM provides comprehensive contracting inspections, permitting guidance, and structural evaluations to ensure safe, compliant, and long-lasting construction outcomes.
Proudly Serving Long Island and Surrounding Areas.
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.