How Much Does It Cost to Add a Dormer?

Gary Evans
by Gary Evans

Space is often limited in many households as building out can be a very expensive undertaking. You will have to pay a substantial amount of money if you want to build on new land. It’s not even a given that the land you’re looking to use for your home addition will be listed on the market.

Instead of splurging on that expensive addition, you can always look up if you need more space. A dormer can add the space you need so consider it carefully for your household. Dormers are somewhat pricey, but they are still more cost-effective relative to your other options.

The average cost to build a standard dormer is $11,000 with labor included. Dormers cost an average of $120 per square foot to build. Building a dormer on an existing attic roof costs $100 per square foot. If you’re building the dormer on an existing bungalow or Cape Cod roof, the average price jumps to $130 per square foot.

Dormers are great investments if you want to increase the amount of space available in your home. They can even be gorgeous additions if they are well-made. Find out how much your ideal dormer will cost by continuing with the rest of this article.

Cost to Add a Dormer by Type

Type of DormerCost Per Square Foot
Arched Roof Dormer$125
Eyebrow Dormer$130
False Dormer$80
Flat Roof Dormer$100
Gabled Dormer$130
Hipped Roof Dormer$120
Pedimented Roof Dormer$180
Recessed Roof Dormer$85
Shed Roof Dormer$100

Dormers are used to add some needed vertical space. On top of that, they can also introduce natural lighting to parts of the home that often lack that valuable resource.

Building a dormer can be a quick and cost-effective way to improve your home. By choosing the right design, you can even use them to improve your home décor. Learn more about the available style options for dormers in the section below.

Arched Roof Dormers

Leading off this list of dormer styles is the arched roof dormer. If you’re interested in building an arched roof dormer, you should know that it will cost about $125 per square foot. It’s one of the more expensive dormer options.

Arched roof dormers are pretty common and they can add a different dimension to your décor. The arched dormers set against the roof can create a beautiful visual.

You’ll also like arched roof dormers because they provide a good amount of space. They offer more space compared to most other types of dormers.

Eyebrow Dormers

You can also add an eyebrow dormer to your home. Eyebrow dormers are pretty expensive. They cost around $130 per square foot to build.

Eyebrow dormers are the additions you build if you want something that provides visual impact. The curves of an eyebrow dormer combine with the small opening to create an interesting design element. It’s the type of home addition you should look to build if you want to add some personality to your home.

The downside to an eyebrow dormer is that it usually doesn’t free up a lot of space. If adding space to your home is your primary concern, you should build a different type of dormer.

False Dormers

False dormers cost approximately $80 per square foot. Why are they so cheap to build? Their design will help explain that.

Those false dormers are named as such for a reason. Unlike other dormers, the false variants don’t add any space at all.

The only function of a false dormer is to change the appearance of your home. You will not even be able to access it even after it has been completed.

False dormers can still be good additions as long as you know exactly what you’re paying for. Feel free to look at the other options if you need something more useful.

Flat Roof Dormers

Flat roof dormers are slightly more expensive than the last option. Those flat roof dormers cost around $100 per square foot.

In stark contrast to false dormers, flat roof dormers are mainly regarded as functional additions. They are arguably the best dormers to build if your only concern is adding as much space as possible. Flat roof dormers aren’t as big as new rooms, but they still introduce plenty of space.

Unfortunately, you’ll have a tough time blending those flat roof dormers into your home décor. Because of how big they are, they will stand out from the rest of your home’s façade in a bad way.

Maintaining that new flat portion of your roof can be somewhat of a hassle. Keep that in mind as you decide if you want a flat roof dormer.

Gabled Dormers

Next up, you have the gabled dormers. Gabled dormers are up there with eyebrow dormers in terms of price as they also cost about $130 per square foot.

Gabled dormers are lauded for their versatility. You can build them big or small depending on the amount of space you need. Tweaking its design is also an option if you want it to pair better with the rest of your home.

A gabled dormer is often finished with a triangular roof. The presence of that triangular roof comes in very handy if you want to just hang out near your gabled dormer. The roof will provide some shade as you try to relax.

Hipped Roof Dormers

Hipped roof dormers cost approximately $120 per square foot. They are among the most expensive types of dormers for a reason.

Those hipped roof dormers share a lot in common with gabled dormers. Both types of dormers are versatile and customizable so they fit more homes.

The differences are present in their appearance. A gabled dormer is covered by material on all sides and its roof is separate from the house. A hipped roof dormer’s roof is connected to the house and it may not utilize as much siding.

Pedimented Roof Dormers

The most expensive type of dormer is the pedimented roof dormer. You can expect to spend around $180 per square foot if you wish to build that type of structure.

Why are pedimented roof dormers so expensive? Their high price tag is related to how they are designed.

Pedimented roof dormers have to be supported by posts from below. You have to pay for the posts and the dormer itself so you can understand why the whole structure costs so much.

A pedimented roof dormer can be a stunning decorative element. It’s up to you to decide if the dimension of design it provides is worth that high price tag.

Recessed Roof Dormers

Adding recessed roof dormers to your home is also an option. They cost about $85 per square foot.

Recessed roof dormers are regarded as modifications to other dormer designs. Gabled and arched roof dormers can still be recessed as long as they don’t extend beyond your roof.

You should consider building recessed roof dormers if you want that added space and natural lighting. However, they can be sources of leakage so make sure they’re designed well.

Shed Roof Dormers

To finish up, we have the shed roof dormers. Shed roof dormers cost approximately $100 per square foot to build.

Shed roof dormers are almost identical to flat roof dormers. The only real difference can be observed in the roof design. Shed roof dormers have sloped roofs so they will just allow moisture to slide off.

Cost to Add Dormer Based on Existing Roof

Type of Existing RoofCost Per Square Foot
Attic Roof$100
Bungalow Roof$130
Cape Cod Roof$130

The cost of building a dormer will be affected by the type of roof you have. We’re going to highlight some of the common roof types that are paired with dormers in this section. Use the information here to get a better idea of how much your project will cost.

Attic Roof

Extending your attic roof with the help of a dormer is possible. That particular project will cost about $100 per square foot.

You can choose from just about all the available dormer styles if you’re working with an attic roof. They should all work well with that kind of structure.

Bungalow Roof

A new dormer for your bungalow roof will cost around $130 per square foot. Dormers for bungalow roofs are expensive because your options are fairly limited.

Gabled and hipped roof dormers are probably the ones that work best with bungalow roofs in terms of design. Even a hipped roof dormer may still look slightly out of place. Paying for the gabled dormer may be necessary.

Cape Cod Roof

Consider adding a dormer to your Cape Cod roof if you want more storage space. Building a dormer on your Cape Cod roof will cost approximately $130 per square foot.

Cape Cod houses typically feature a classic appearance. That does limit your dormer options somewhat. Gabled dormers are often paired with Cape Cod roofs. You can also go with an arched roof, hipped roof, or shed roof dormer.

Related Questions

How Much Does a Prefab Dormer Cost?

Prefab dormers are available if you need the extra space added as soon as possible. The average cost of a prefab dormer is right around $11,000.

How Much Will You Have to Pay for a Dormer Building Permit?

Some areas require homeowners to secure permits before building a dormer. Those dormer building permits usually cost around $500 to $550.

How Much Will a Bathroom Dormer Cost?

Adding a dormer to an existing bathroom will be expensive. A single bathroom dormer costs about $24,000 to complete. You have to pay more for a bathroom dormer because you will likely have to modify a larger segment of your home.

Gary Evans
Gary Evans

Gary Evans is passionate about home improvement. He loves finding out how to make improvements in the easiest, most practical, and most affordable ways. Upgrading his home kitchen is one of his ongoing hobbies. Gary is also a long-time content creator and enjoys spending his free time tending to his hydroponic vegetable garden.

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