Addition & Alteration Contractor

Q: What’s the difference between an addition and an alteration?

An addition increases your home's square footage, while an alteration modifies the existing layout or structure without expanding the footprint.

Q: Can you match the new addition to the existing structure?

Yes, we ensure all additions blend seamlessly with the existing structure through matching materials, finishes, and architectural details.

Q: Do additions add value to a property?

Yes, well-planned additions can significantly increase property value, improve functionality, and enhance long-term usability.

Expert Additions & Alterations Designed for Structural Integrity and Modern Living

Expand and enhance your property with our addition contracting services built to meet modern standards, structural requirements, and long-term performance goals. We handle room additions, floor expansions, layout reconfigurations, dormers, extensions, structural upgrades, and interior/exterior alterations for residential, commercial, and multi-unit buildings. Our team manages every phase—from planning and permitting to framing, mechanicals, and finishing—ensuring all work meets code, integrates seamlessly with the existing structure, and supports your property’s future needs.

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What We
Offer

01

Full Home Addition

We build full‑scale home additions that expand living space with new foundations, framing, utilities, and premium finishes. This service delivers a seamless extension of the home with modern comfort and long‑term value.

03

Garage Conversions & ADU Build‑Outs

We convert garages into livable spaces or build accessory dwelling units with full plumbing, electrical, insulation, and custom layouts. This service adds rentable or multi‑use square footage with strong ROI.

02

Second‑Story or Vertical Additions

We add new floors or expand upward with structural reinforcement, new layouts, upgraded mechanicals, and full interior build‑outs. This service dramatically increases square footage without sacrificing yard space.

04

Multi‑Room Expansion Packages

We expand multiple areas of the home at once—such as adding square footage to kitchens, living rooms, and bedrooms—complete with new foundations, framing, utilities, and premium finishes. This delivers a cohesive, large‑scale upgrade.

Who We Serve

New York

Bronx, NY
Queens, NY
Brooklyn, NY

Staten Island, NY
Manhattan, NY
Westchester County, NY

Nassua County, NY
Suffolk County, NY

New Jersey

Hudson County, NJ
Essex County, NJ
Union County, NJ

Bergen County, NJ
Middlesex County, NJ

NATIONAL COMMERCIAL GENERAL CONTRACTING SERVICES

Addition & Alteration FAQs

1

What’s the difference between an addition and an alteration?

An addition increases the building’s footprint or square footage, while an alteration modifies the existing structure—such as reconfiguring layouts, adding dormers, removing walls, or upgrading mechanical systems. Both require proper planning, permitting, and structural review.

2

Can you match the new addition to the existing structure?

Absolutely. We ensure the new work blends seamlessly with the original building—matching materials, finishes, rooflines, mechanical systems, and architectural details for a cohesive final result.

3

Do additions add value to a property?

Yes. Well‑planned additions—such as extra bedrooms, expanded living areas, or commercial space upgrades—typically increase property value, improve functionality, and enhance long‑term usability.