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Roof Dormers

are a popular form of roof extension. Homeowners with available or
potential attic living space are especially interested. Dormers are
essentially built out of the existing roof. They have gabled ends and
typically one to two windows. The purposes of a dormer as an extension
of the house is to allow added living or storage space and provide air flow and natural light.

may also have flat roofs, but are usually gabled or “cottage-style”
additions. Dormers may also be “fake.” That is, they are sometimes
built onto the roof as a purely aesthetic architectural feature. They
make the home look bigger than it actually is. Fake windows are
often built into these dormers with a section of plywood or even glass
painted black to give the illusion of interior depth. Even these “fake”
dormers may have a hole cut in the roof beneath them and a vent
installed to promote air flow. This is a more practical application.

Beyond function, dormers
offer certain aesthetic benefits as well. Not only do they give the
home a more historical, larger feel, but they can provide a view that
is impossible from the floor or floors beneath. Dormers have a history
of being inspirational outlooks for writers and artists.

Roof dormer additions have been used in homes for centuries. Their main purpose is to add extra living and storage space, or they are built simply because they’re aesthetically pleasing. If a roof dormer addition is something you’d like for your own home, we have all the information you need to get started.


The cost of installing a roof dormer depends on a few factors: the type and quality of the roofing and construction materials, the size of the dormer, and professional labor rates in your area. Hiring a contractor for a dormer the size of a single- or double-wide window should cost between $2,500 and $5,000. However, larger dormers could cost as much as $20,000.


Roof dormers add additional living or storage space to a home.

They can help with air flow and natural light, and even provide a reading nook or window seat.

Roof dormers can add a traditional element to a variety of homes.


Roof dormers can be costly additions.

Because they protrude outward, roof dormers can be hard to maintain.

May be complicated and time-consuming to install.


For the most part, the durability of roof dormers depends on the materials used to construct them. Consult with your contractor about how to care for your roofing material, new windows and any other major concerns.

Common Questions and Answers

Are all roof dormers mostly for functional purposes?

No, sometimes they are “fake” roof dormers. That is, they are built onto the roof as a purely aesthetic architectural feature to make the home look bigger than it actually is.

Fake windows are often built into these dormers with a section of

Is there more than one type of roof dormer?

Yes, roof dormers are generally either built-out (the most common), partially built-out/partially cut-in dormers, and cut-in dormers (the least common).


Dormer roofs first appeared in the 17th century and can be attributed to the architect Francois Mansart, who also designed what are now known as Mansard-style hip roofs.

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