Licensed contractor with 10+ years of experience transforming unfinished basements into beautiful living spaces across Suffolk County and Nassau County.
At Gonzaga Professional Builders, we specialize in basement finishing in Long Island, NY. Whether you want to create a home theater, a guest suite, a home office, or a multi-purpose family room, our experienced team transforms underutilized basements into stunning, functional living spaces.
As a licensed remodeling contractor in Suffolk County and Nassau County, we handle every aspect of your basement conversion — from waterproofing and insulation through framing, electrical, plumbing, drywall, flooring, and custom finishes. Our in-house architect ensures all permits and codes are properly addressed.
Complete transformation of unfinished basements into comfortable living spaces with proper insulation, drywall, flooring, lighting, and climate control.
Custom home theater build-outs with soundproofing, tiered seating platforms, dedicated electrical circuits, and media wall installations.
Dedicated workspace solutions with proper lighting, electrical outlets, data wiring, climate control, and sound isolation from the rest of the home.
Complete guest living quarters with bedroom, bathroom, kitchenette options, and egress windows to meet all safety and building code requirements.
Full and half bathroom installations including plumbing rough-in, fixtures, tile work, ventilation, and proper drainage solutions.
Comprehensive moisture control with interior drainage, vapor barriers, spray foam insulation, and dehumidification systems for a dry, comfortable space.
Browse our recent basement transformations across Suffolk County and Nassau County. Every project reflects our commitment to quality craftsmanship.
Over a decade of basement finishing experience across Long Island. We understand the unique challenges of Long Island basements including moisture, low ceilings, and foundation considerations.
Fully licensed contractor with comprehensive insurance coverage. Your home and investment are protected throughout every phase of the project.
Our in-house architect handles permit facilitation, egress requirements, and ensures your basement project meets all local building codes.
Detailed written estimates with no hidden fees. We provide honest pricing and keep you informed at every stage of your basement conversion.
We coordinate all trades — framing, electrical, plumbing, HVAC, drywall, flooring — so you have a single point of contact throughout the project.
Every basement finishing project comes with a comprehensive workmanship guarantee. We stand behind the quality of our work long after the project is complete.
We assess your basement's condition, discuss your vision, evaluate moisture levels and structural elements, and provide a detailed written estimate — completely free.
We create a layout that maximizes your basement's potential, plan for proper egress, HVAC, and electrical needs. Permit facilitation handled by our in-house architect.
Address any moisture issues with proper waterproofing, install vapor barriers, and prepare the space with insulation and structural modifications as needed.
Framing, electrical, plumbing, drywall, flooring, trim, painting, and fixture installation — all executed by our experienced team with constant quality supervision.
Thorough quality inspection and walkthrough with you to ensure every detail meets your expectations. We don't consider a project complete until you're satisfied.
We proudly serve homeowners throughout Long Island, NY. Our basement finishing services are available in the following areas and surrounding communities:
Basement finishing costs in Long Island typically range from $20,000 to $50,000 for a standard conversion, while high-end build-outs with bathrooms, wet bars, or home theaters can range from $50,000 to $100,000+. Contact us for a free, personalized estimate.
A typical basement finishing project in Long Island takes 4 to 8 weeks depending on the scope. Simple finishing with drywall and flooring may take 3-4 weeks, while full conversions with bathrooms and custom build-outs can take 8-12 weeks.
Yes, finishing a basement in Suffolk County requires building permits, especially when adding electrical, plumbing, egress windows, or changing the use of the space. Gonzaga Builders handles the entire permit process through our in-house architect.
Yes, we regularly add full and half bathrooms to basement conversions. We handle all plumbing, including sump pump considerations and proper drainage, to ensure a fully functional and code-compliant bathroom.
Yes, proper waterproofing and moisture control are essential parts of every basement finishing project we do. We address drainage, vapor barriers, insulation, and dehumidification to ensure a dry, comfortable living space.
Absolutely. A professionally finished basement can add significant value to your home and increase usable living space by 30-50%. It's one of the best return-on-investment home improvement projects you can do in Long Island.
Contact us today for a free consultation and estimate on your basement finishing project in Long Island, NY