You’re not outgrowing your neighborhood. You’re outgrowing your floor plan.
A dormer addition solves that without the nightmare of moving. You get functional living space where there was just dark attic before. Natural light floods in. Your kids get separate rooms. You finally have a home office that isn’t the kitchen table.
The North Shore market is brutal right now. Homes in Roslyn Harbor are selling fast with multiple offers, and median prices across Nassau County hit $644,000. Moving means competing in that chaos, paying more per square foot, and likely settling for a different school district or longer commute.
Or you stay put and build up. A dormer gives you 150 to 400 square feet of finished space, depending on your roofline and layout. That’s a real bedroom, not a glorified closet. It’s an investment that returns 40-50% of the cost when you eventually sell, and in the meantime, you’re living in a home that actually fits your life.
We’ve been handling major renovations across Nassau and Suffolk County for over 40 years. Dormers, extensions, full kitchen and bathroom remodels—the kind of work that actually changes how you live in your house.
We’re licensed, insured, and bonded. Our BuildZoom score puts us in the top 1% of contractors in New York, which matters when you’re cutting into your roof and adding structural load.
Roslyn Harbor homeowners deal with the same issues we see across the North Shore: older Colonials and Cape Cods with great bones but layouts that don’t work for modern families. We know how to blend new construction into existing architecture so it doesn’t look like an afterthought. And we keep job sites clean, show up when we say we will, and answer the phone—things that shouldn’t be differentiators but somehow are in this industry.
First, we come out to look at your attic and roofline. Not every house is a good candidate, and we’ll tell you straight if yours isn’t. Assuming it works, we measure everything, talk through what you want to use the space for, and put together a detailed estimate.
Once you’re ready to move forward, we handle permits if needed. Then we build the dormer frame, typically a shed or gable style depending on your home’s architecture and your budget. Shed dormers are more affordable and give you the most usable space. Gable dormers cost more but add serious curb appeal.
We tie the new structure into your existing roof, frame out walls, install windows, and get everything weathertight before moving inside. Insulation, drywall, electric, HVAC if you’re adding it—all the finish work that turns framing into a room you’d actually want to be in.
Most dormer projects take 4 to 8 weeks start to finish, depending on size and weather. Long Island winters can slow things down, but we work year-round. You’ll have dust and noise during construction, but we clean up daily and keep disruption as minimal as possible when we’re cutting into the space you’re living in.
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A dormer isn’t just about square footage. It’s about making your attic habitable, which means solving ventilation, insulation, and light problems all at once.
You get windows that actually open, so the space doesn’t turn into an oven in summer. Proper insulation keeps it comfortable year-round and cuts down on energy waste—Long Island winters will find every gap in your building envelope, and heating an uninsulated attic is like burning money. We make sure your new space is sealed tight and ventilated right.
The structure itself is engineered to handle the load. We’re not just slapping a bump-out on your roof. Everything gets properly framed, flashed, and integrated so you don’t end up with leaks or sag five years down the line. Roofing, siding, trim—it all matches your existing home or we coordinate an update so the whole house looks intentional.
Inside, you get a finished room. Drywall, paint, flooring, electric outlets, lighting. If you’re adding a bathroom up there, we run plumbing. If it’s a bedroom, we make sure it meets egress code with a proper window. The goal is a space that feels like it was always part of the house, not an add-on you’re making excuses for.
Most dormer projects in Nassau County run between $18,000 and $40,000, depending on size, style, and how finished you want the interior. A basic shed dormer that adds 150 square feet of space and gets framed, insulated, and drywalled will land on the lower end. A larger gable dormer with custom windows, a bathroom, and high-end finishes will push toward the upper range or beyond.
The biggest cost drivers are size and complexity. Cutting into your roof and adding structural framing is labor-intensive. Then there’s everything that goes inside: electric, HVAC, flooring, trim. If you’re adding plumbing for a bathroom, that’s another jump.
We give you a detailed estimate upfront so there’s no guessing. The number we quote is the number you pay unless you change the scope mid-project. And yeah, it’s an investment—but you’re adding real square footage to your home in a market where space is expensive and hard to find.
Plan on 4 to 8 weeks from start to finish for most projects. Smaller shed dormers on the quicker end, larger or more complex builds on the longer end.
Weather plays a role, especially in winter. We work year-round, but snow, ice, and freezing temperatures can slow things down when we’re working on your roof. Permits can add time on the front end if your project requires them, though not all do depending on scope and local requirements.
The actual construction breaks down into phases. Framing and getting the structure weathertight happens first—that’s the loudest, most disruptive part, but it usually wraps in a week or two. Then interior work: insulation, drywall, electric, finish carpentry. That’s where the bulk of the time goes, but it’s also quieter and less invasive. We’re not tearing your house apart for months. You’ll have a finished, usable room in under two months in most cases.
If it’s done right, yes. If it’s done poorly, it’ll stick out like a bad toupee.
We specialize in blending new construction with existing architecture. That means matching rooflines, siding, trim, and window styles so the dormer looks like it was part of the original build. A lot of homes in Roslyn Harbor and across the North Shore are Colonials or Cape Cods from the mid-20th century. Those styles have specific proportions and details, and we pay attention to that stuff.
Gable dormers tend to integrate more naturally with traditional home styles because they echo the existing roofline. Shed dormers are more modern and utilitarian, but they maximize interior space and can still look clean if the details are right. We’ll walk you through options during the planning phase and show you what makes sense for your house. The goal is added space that increases your home’s value and curb appeal, not a weird bump that makes people wonder what you were thinking.
Usually, yes. Any time you’re altering your roofline or adding structural elements, Nassau County wants to see plans and issue a permit. That’s not us being difficult—it’s code.
The permit process involves submitting drawings, getting approval from the building department, and scheduling inspections at certain phases of construction. We handle that coordination. You don’t need to figure out what forms to file or when to call for inspections.
Some smaller projects might not trigger permit requirements depending on scope, but most dormers do. The timeline for permit approval varies, but it typically adds a couple of weeks to the front end of the project. It’s a hassle, but it’s also protection for you. Permitted work means the structure is engineered correctly, inspected by the town, and documented if you ever sell. Unpermitted work can come back to bite you during a home sale or insurance claim, and it’s not worth the risk to skip it.
Yes, and it’s one of the most common requests we get. A dormer with a bathroom turns your attic into a true second-floor suite, which is a huge value-add if you’ve only got one full bath on the main level.
The challenge is plumbing. You need to run water supply lines and drain lines up from the floor below, which usually means opening walls or working through existing chases. It’s doable, but it adds cost and complexity compared to a simple bedroom or office.
You also need to think about ventilation and layout. Bathrooms generate moisture, so proper exhaust fans and vapor barriers are critical to avoid mold problems down the line. And the space needs to be laid out so the toilet, sink, and shower actually fit without feeling like an airplane lavatory. We’ve done enough of these to know what works and what doesn’t. If a bathroom makes sense for your dormer, we’ll tell you. If it’s going to be a cramped, expensive mess, we’ll tell you that too.
Shed dormers have a single sloped roof that extends from the existing roofline. They’re simpler to build, cost less, and give you the most usable interior space because the ceiling height is more consistent. If your main goal is maximizing square footage, a shed dormer is usually the way to go.
Gable dormers have a peaked roof that projects out from the main roofline, creating a triangular shape. They’re more traditional looking and add more curb appeal, but you lose some interior space to the angled ceiling. They also cost more because the framing is more complex.
There’s also the eyebrow dormer, which is mostly decorative and doesn’t add much usable space, and the hipped dormer, which is less common. For most Long Island homes, you’re choosing between shed and gable based on budget, how much space you need, and what looks right on your house. We’ll show you examples of both and help you figure out what makes sense for your situation.
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