Dormer Additions on Long Island.
Raise the roof. Keep the footprint. Add a full primary suite without touching the foundation.
Dormer walk-through
The owner or our addition superintendent will visit and scope the job within 7 days.
Why Long Island Homeowners Choose Dormer Additions
A dormer addition is the fastest way to double your usable upper-floor space without expanding the footprint of your home. On Long Island, where lot coverage limits in Nassau and Suffolk often prevent building out, going up through a dormer is the practical, code-compliant answer to the space problem. Shed dormers, Cape Cod conversions, and full dormer additions let homeowners add a primary suite, extra bedrooms, or a home office under a raised roofline — all while keeping the yard, driveway, and setbacks untouched.
Since 2007 our dormer crews have framed and finished over 170 dormer projects across Long Island. Every dormer we build follows the same one-day strip-and-frame protocol: the existing roof comes off at 7 AM, new framing goes up by mid-afternoon, and the structure is sheathed and watertight before the crew leaves. This approach minimizes weather exposure and lets your family stay in the home through nearly the entire build. From PE-stamped structural plans through final paint, we handle permits, inspections, and every trade in-house so there is one point of contact and one fixed-price contract.
Dormer Additions Long Island — Nassau & Suffolk County
We complete dormer additions across all of Long Island — Nassau County communities including Garden City, Hempstead, and Mineola, and Suffolk County towns including Huntington, Babylon, and Smithtown. Every Long Island township has its own permit process and building department, and our team has navigated them all since 2007. Types we build: shed dormers (the full-width raised-roof configuration that creates the most space), gabled dormers (single symmetrical dormer popular on colonials and Tudor revivals), and hip dormers (suited to hipped-roof homes where a shed dormer would alter the roofline profile). Cost ranges for dormer additions on Long Island typically run $25,000–$65,000 for smaller gable dormers and $75,000–$145,000 for full shed dormers including structural engineering, permits, framing, roofing, windows, insulation, and drywall. Interior finishes are quoted separately. The owner visits every site before pricing — call or submit the form to schedule.
Our Garden City dormer addition team has completed 15+ projects in Nassau County's most architecturally demanding community. Garden City's Historic District ARB process, Village Building Department permit requirements, and strict material-matching standards for Tudor revival and center-hall colonial homes make it a specialized sub-market within Long Island dormer work. Learn more on our dedicated Dormers Garden City NY page.
Serving every Long Island township
Dormers Old Bethpage
1960s ranches and hi-ranches with low-pitch roofs ideal for full shed dormers. Town of Oyster Bay permits — we know the building department.
Dormers Oyster Bay
Colonial and Cape stock in the TOB. Dormers matched to cedar shake and clapboard originals. ARB-sensitive builds in the village districts.
Dormers Muttontown
Estate-zone dormers on larger lots. Village of Muttontown requires architectural review — we've cleared it on multiple builds.
Dormers Bethpage
Classic 1950s Cape Cod territory. Raise-the-roof conversions that double the second floor. Town of Oyster Bay permits handled.
Dormers Williston Park
Tight-lot Capes and colonials in the Village. We navigate the Village Building Department and keep neighbor-facing facades clean.
Dormers Garden City
Tudor and Colonial dormers under Village Building Dept oversight. Historic District ARB experience and material-matched construction.
Five dormer configurations
Shed Dormer
Single long pitched-roof addition. Max floor area and headroom for a Cape or ranch. Our most common build.
Full Dormer
Takes the entire second story out to the wall — essentially a new full-height floor. 800–1,200 sq ft of new living space.
Cape Cod Dormer
Our LI specialty. Raise-the-roof on 1950s Capes across Levittown, Hicksville, Bethpage. 90+ Capes dormered.
Dormer Addition
Add a bedroom, bathroom, or primary suite via targeted dormer. Permit-to-paint turnkey.
Attic Dormer
Unfinished attic to finished suite — dormer adds the headroom, egress, and natural light.
Second Story Partial
Half-footprint dormer build for homes where a full second story isn't needed or wanted.
On the boards right now
Full Shed Dormer + Primary Suite — Levittown, NY
Stripped the roof on a 1953 Cape, framed and watertight day one. Added 840 sq ft primary suite with walk-in and spa bath. Town of Hempstead permit.
Cape Cod Conversion — Hicksville, NY
Raised the roof on a 1954 Cape — added two bedrooms, a full bath, and a reading nook. Town of Oyster Bay permit.
Attic Conversion with Dormer — Bethpage, NY
Unfinished attic to finished suite — dormer added headroom, egress, and natural light. 420 sq ft bonus room conversion.
About dormer additions
A shed dormer is a single long pitched roof section lifted from the main roof — it creates the maximum amount of headroom and floor area under a Cape or ranch roof. A full dormer takes the entire second floor out to the wall line, which essentially converts the upper half of the house into full-height rooms. We build both, and we'll recommend based on your roof pitch, existing framing, and zoning coverage.
The framed-and-watertight day is the critical one: we strip the roof at 7am, frame by mid-afternoon, and sheath or tarp before dinner. From permit-to-paint (including interior finishes) a typical shed dormer runs 6–9 weeks. Plans and permitting add 4–8 weeks on the front end depending on the township.
Usually no. A shed dormer only opens the upper floor — the lower level of the house stays fully livable. The one-day strip-and-frame is noisy and dusty, but we tarp interior spaces and clean nightly. Full second-story additions are different and often do require a rental for 4–6 weeks mid-build.
Pricing depends on dormer size, finish level, and structural scope. The honest answer is 'come walk the site and we'll tell you.' We don't publish numbers because every Cape Cod is different — an 1856 pre-war frame and a 1953 Levitt Cape cost different amounts to reinforce. We give a firm fixed-price quote after the walk-through.
Yes — they're a third of our dormer work. Long Island's 1950s Cape stock is prime for raise-the-roof conversions. We've done 90+ Capes since 2007 across Levittown, Hicksville, Bethpage, and Seaford.
Absolutely — that's the most common ask. A full shed dormer typically yields 800–1,200 sq ft of new living space, which easily accommodates a primary bedroom, walk-in closet, spa bath, and a reading nook. We coordinate with your architect (or our in-house AIA) to maximize the usable layout.
Yes — dormers in Garden City are among our most specialized projects. Garden City is an incorporated village with its own Building Department and Historic District Architectural Review Board. We've completed 15+ dormer additions in Garden City since 2007, including shed dormers on center-hall colonials ($90K–$145K) and gable dormers on Tudor revivals ($75K–$110K). Our in-house architect handles every Garden City ARB application — every submission approved. See our dedicated dormers Garden City NY page for full details on pricing, permits, and the ARB process.
Wondering what a dormer will cost on your house?
Read our 2026 Long Island dormer addition cost guide — real ranges for shed, Cape, and full dormers, permit costs by town, and what drives the number.
Dormer additions on Garden City's Tudor & Colonial homes
Village Building Dept permits, Historic District ARB experience, and material-matched dormers on Garden City's 1920s–1950s housing stock. Shed dormers $90K–$145K.
Ready to raise the roof?
We can have a framed-and-watertight dormer on your Cape or ranch in under 10 weeks from signed contract.
Mon–Fri, 7am to 6pm | Saturdays by appointment · Call or text anytime