Basement Finishing & Renovations
Turn your unfinished basement into valuable living space — home offices, entertainment rooms, guest suites, and more.
Your basement is one of the largest unused spaces in your home. A professionally finished basement adds significant living space and property value without the cost of an addition. JZ Development provides basement finishing and renovation services across Long Island, transforming dark, damp basements into beautiful, functional rooms.
Our basement finishing process starts with moisture management — the most critical step for Long Island basements. We address any water intrusion issues, install vapor barriers, and ensure proper drainage before any framing begins. Then we frame walls, run electrical and plumbing (if needed), insulate, install drywall, flooring, and finish work.
Popular basement conversions include home offices, entertainment and media rooms, playrooms, home gyms, guest bedrooms with full bathrooms, wet bars, and combination spaces. We design layouts that make the most of your available square footage while working around mechanical systems, support columns, and egress requirements.
Every basement is unique, and we tailor our approach to your specific space, goals, and budget. Whether you want a basic finished basement with carpet and painted walls or a high-end living space with custom built-ins, heated floors, and a full bathroom, JZ Development delivers quality results.
What We Do
- Full basement finishing
- Basement bathroom installation
- Home office conversion
- Entertainment & media rooms
- Basement bedroom with egress
- Wet bar & kitchenette
- Basement waterproofing & prep
Basement Finishing Across Long Island
We provide basement finishing services throughout Nassau and Suffolk County:
Frequently Asked Questions
How much does basement finishing cost on Long Island?
Basement finishing on Long Island typically costs $30-$75 per square foot, depending on finishes and features. A basic 800 sq ft finished basement (framing, drywall, flooring, lighting) runs $24,000-$60,000. Adding a bathroom, wet bar, or high-end finishes can push costs higher. We provide detailed estimates tailored to your project.
Do you handle basement waterproofing?
Yes. Moisture management is the first step in any basement finishing project. We address water intrusion, install vapor barriers, and can coordinate interior drainage systems and sump pumps when needed. We won't build over moisture problems — we solve them first.
Can I add a bathroom to my basement?
Yes. Basement bathrooms are one of the most valuable additions to a finished basement. If your plumbing doesn't already extend to the basement, we can install an up-flush system or break the slab for traditional below-grade plumbing. We handle all plumbing, tiling, fixtures, and ventilation.
Do I need an egress window for a basement bedroom?
Yes. Building code requires egress windows or doors in any basement bedroom for emergency exit. The window must meet minimum size requirements. We install egress windows as part of basement bedroom conversions, including the window well and drainage.
How long does basement finishing take?
A typical basement finishing project takes 4-8 weeks from start to finish. Basic finishes with no bathroom may take 3-4 weeks. Projects with bathrooms, custom features, or extensive plumbing/electrical work may take 6-10 weeks. We provide a detailed timeline during planning.
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Get a free estimate for your basement finishing project on Long Island. We're here to answer your questions and help bring your vision to life.