We have LOTS of older Cape style homes in Massachusetts and many homeowners are looking for ways to increase their living space. With sloped second floor ceilings limiting square footage, adding dormers to a Cape can be a relatively inexpensive way to gain space.
Gabled window dormers can add curb appeal and are less costly to build, while a full shed dormer, usually done in the back of the house, can allow for the addition of a bathroom.
Just a shed dormer itself may start around $20,000 but expect plenty of variation in cost depending on the size, materials used, and whether the new space will be used for a bathroom (i.e. added plumbing and electrical costs) or bedroom.
Often one project means others as well, so consider whether the dormer will mean replacing an entire roof, all the siding, or other windows in the house to match.
As with any renovation, it's a good idea to start with plans and choose a few different contractors to price the project, making sure to check references before moving forward with anyone. A dormer can grow to be a large project but can be kept simple and mean better curb appeal, increased living space, and higher resale value.