A shed dormer is a smart way to add extra space and headroom to your house, without expanding its footprint. this tool will help you quickly estimate the cost of building a shed dormer on your roof or unused attic.. Homeowners typically add dormers as part of the process of transforming the attic into a usable living space. adding a 15-foot shed dormer to accommodate a new 15-by-15-foot bedroom and 5-by-7 bathroom in the attic costs an average of $49,438 as of 2014, according to remodeling magazine.. Shed dormers range in price from around $5,500 for a 12-footer to $11,500 for a 30 foot dormer. hip dormers can cost anywhere from $4,000 up to $15,000 depending on what it’s being used for and the size of the dormer. get local window costs . types of dormers & costs. dormers come in three very different styles, gable, shed and hip..
Cost variation via dormer style. for anyone who asks ‘how much does dormer cost,’ the most visible factor that follows after the basic cost drivers is the style. these are the three types of dormers and their corresponding costs as presented by modernize: gabled dormer. A window dormer usually costs around $4,000, according to doiron. bathroom dormer average around $23,000 to $25,000, including the cost of materials. when adding multiple rooms, doiron says you can quickly climb to a total of more than $100,000..