How much does it cost to install a dormer roof?

Reviewed by Adam Graham remodeling expert. Written by Fixr.com.

If you have a Cape Cod style home, you are also the owner of a dormer roof. Dormer roofs are technically a subtype of gable roofs. They have the distinction of having dormer windows cut into the roof at the front of the home, while also changing angle and pitch toward the rear of the home. This type complements homes like the Cape Cod that use both dormers in the front and a lower pitch in the back.

Because of the pitch changes and the presence of dormers, this roof has higher starting costs than other similar roofs like the gable. The national average cost for replacing the material on a dormer roof is $8,000 to $20,000, with most people paying around $10,000 for an installed 1,500 sq.ft. dormer roof with architectural shingles. This project’s low cost is $7,000 for a 1,500 sq.ft. dormer reroof using 3-tab asphalt shingles. The high cost is $50,000 for an installed 1,500 sq.ft. dormer roof with natural slate shingles.

What Is a Dormer Roof?

Dormer roofs are designed for homes like the Cape Cod. These homes feature a normal pitch roof on the front, with 2 to 3 dormer windows inset into it. From the inside, these dormers provide more space to the home’s top level. On the backside of the home, it has a slightly more shallow pitch, allowing for greater height inside the home’s top floor.

The changing pitch does not dramatically increase or impact the cost of the roofing project. However, the addition of the dormer windows does. The dormers each have their own small roof and need to be properly flashed and sealed to keep moisture out. This means that the starting costs for a dormer roof are higher than standard gable roofs, which do not have these inset windows.

Dormer Roof Cost Calculator

Dormer roofs can use the same roofing materials as other similar roofs. This includes cost-saving materials like 3-tab asphalt shingles and more luxury items like copper and slate roofing. The only complex part of the installation is around the dormers, meaning that while material costs are the same for other roofs of the same size, the labor costs can be higher. The more dormers, the higher the costs. Below are the average costs to install materials of different qualities on a 1,500 sq.ft. dormer roof with 3 dormer windows.

Dormer roofs use the same materials as gable, hip, and other popular roofs. This includes low-cost materials like 3-tab asphalt shingles, plastic shingles, and standard materials like standing seam metal panels, some concrete tile types, and architectural shingles. High-quality materials include metal tiles, clay tiles, high-end architectural shingles, and materials like cedar and slate shingles. With some materials, you may have additional costs for roof reinforcement, particularly with heavy materials, such as slate and clay tile that can increase the final costs.

Dormer Roofs Pros and Cons

Dormer roofs complement the Cape Cod home. The dormers on the front of the roof offer light and additional space and a little more headroom for the front of the home’s top floor. The lower pitch in the back of the home also offers more headroom. This means that anyone with a bedroom on the top floor of a Cape Cod will be a little more comfortable than if the space had a gable roof.

The only real downside is that it is more expensive to roof. Each dormer needs to be flashed, fitted, and have its own covering. This makes the labor harder and more costly. The lower pitch on the backside of the home may make it more likely to develop issues with ice dams and moisture because it may not get as much run-off as a roof with a higher pitch.

Additional Considerations and Costs

• Lifespan. The lifespan of a dormer roof is similar to any other roof with the same material.
• Maintenance. The material directly influences the maintenance. It may require extra inspections to ensure that the lower slope does not develop leaks and the dormers are well-sealed.
• Flashing. Flashing needs to be installed around all protrusions, the roof edging, and around each dormer. This has a cost of $10 to $25 a linear foot.
• Roof deck. The roof deck is the material your roofing is installed on, which is over the rafters. If this becomes compromised, you need to install a new one. This costs between $800 and $2,800.