Home

Dormer

A dormer is a roofed projection that extends vertically from a pitched roof, housing a window. Dormers add usable space and headroom to attics and lofts and improve daylight and ventilation in upper-floor rooms.

Common types are gable dormers, which have a triangular gable above the window; shed dormers, with a

Dormers must be carefully integrated into the existing roof structure. They require proper framing, waterproofing, and

Historically dormers appeared in medieval and early modern European architecture and became common in later vernacular

Advantages include increased space, light, and ventilation, while disadvantages can include higher construction costs, potential for

single-plane
roof;
hip
dormers,
which
have
a
hip
roof
on
all
sides;
and
eyebrow
dormers,
which
feature
a
low
curved
profile
that
rises
only
slightly
above
the
roofline.
flashing
to
prevent
leaks.
Their
installation
adds
structural
load,
can
alter
roof
drainage,
and
may
affect
thermal
performance
and
exterior
appearance.
In
some
jurisdictions,
planning
permission
or
building
codes
may
apply.
and
formal
styles,
including
Georgian
and
Victorian
houses.
Today
they
are
frequently
added
during
loft
conversions
or
as
a
design
feature
to
increase
daylight
in
upper
rooms.
leaks
if
poorly
installed,
and
changes
to
roof
slope
and
overall
aesthetics.
Alternatives
include
skylights
or
roof
windows
that
do
not
add
space.