Dormer Costs: You'll Need to Expect These Items

Dormer Costs: You'll Need to Expect These Items

Whether reading corner or more storage space: The dormer is the number one alternative when it comes to installing new items in the attic. But many a homeowner runs in the cost jungle and loses the overview.

Roof Dormer Costs

A dormer is a convenient way to add more space to the top floor and let light and air in. The following lines explain the owner's cost positions when installing a dormer. But with the purchase of the dorm it is not done, more positions will be incurred. These can be roughly subdivided into the following categories:

  • Preliminary work (static calculations)
  • Acquisition price of the dormer window
  • Transport costs to the building site
  • Installation costs and adjustment costs

Preliminary work and calculations

A dormer does not build without the theoretical considerations in the roof. For the statistical calculations it takes an architect or civil engineer. These costs depend on his hourly rate, many architects work after the rule honoring HOAI 2009, around 70 euros (net) are paid here on average per hour. About ten man-hours are needed for statistical calculations, construction drawings and form processing. That's why around 700 euros net is a good guideline.

Many a dormer manufacturer works closely with experts and assumes these costs, which then disappear in his calculations. Here, the cost estimate should be paid close attention, but is usually free of charge.

For the subsequent installation of a dormer a building permit is required. Again, there are construction fees. However, the amount and the directives themselves vary from one federal state to another.

Acquisition price of the dormer window

Next is the selection of the dormer window. Again, different acquisition costs are to be expected, because there are many different models that can be installed in the roof. The cost of the dormer depends mainly on the following three factors:

  • dormer shape (window)
  • dormer size
  • prefabricated dormer or single construction

There are several types of dormers available in the trade. The simpler and less expensive the production is, the cheaper they are. The following forms are available for the following recommended prices:

  • Flat roof dormer: less than 3000 Euro
  • Roof dormer: approx. 3000 Euro
  • Delta dormer: approx. 3500 Euro
  • Saddle roof dormer: between 3500 and 4000 Euro
  • Segment dormer: between 3500 and 4000 Euro
  • Bat Roof Dormer: over 5000 Euro

A price comparison with different providers for the same model can be worthwhile here. However, the builder should pay attention to which works are included in the price.

But also the dimensions of the dormer determine the cost of their purchase. Thus, wider and higher dormers housing several windows are considerably more expensive than small dormers with only one window.

Finally, the production process plays a role in the purchase price. There are numerous prefabricated roof dormers, which are manufactured in a standardized process. Of course, these are much cheaper than special constructions that can only be found once. For unique items, builders have to dig deeper into their pockets.

Transportation costs

The retail price includes delivery charges and transport costs. These also depend on the size of the dorm - the larger, the more difficult the transport. The distance also plays a role. Around 500 Euro shipping costs are usual, but also 1000 Euro can be booked here. Therefore, find a manufacturer in your area who does not have to transport the installation for many kilometers.

Installation of the dormer

If the dormer is bought and delivered, it can be installed. Other costs include:

  • Use of a crane
  • Scaffolding rental, erection and dismantling Scaffolding
  • Execution of a roof opening
  • Revising the roof covering at the edges
  • Working hours of the roofer
  • Side paneling
  • Interior fitting

The roof opening, for example, can cost around 250 euros, the assembly of the dormer is to be calculated with a whole working day and will cost around 800 euros. The interior construction beats at around 500 euros. The roof cover of the dormer depends on the bricks used - after all, they should also match the entire roof. The side panel can be made of titanium zinc or even made of glass favorably. An average of 2,500 euros must be earmarked for the installation of the dormer window - but the price can also be higher.

Factors that increase costs

As with any building project, there are also other factors involved in installing a dormer window Costs in addition shoot up. These are often special requests such as:

  • Special constructions
  • expensive windows
  • higher thermal insulation
  • Shutters and sunblinds
  • additional waterproofing
  • expensive roof covering

In addition to the low-priced prefabricated dormers, there are also special constructions can be significantly more expensive in the purchase. Dacherker and Zwerchhäuser are included here. They need particularly good planning and their production is not standardized.

But windows can also make the costs of a dormer window significantly more expensive. If you want to have a special window shape, you have to pay more. The materials are also different. It is costly for wooden windows and real, oversized windows, but special functions also make the construction project more expensive.

However, higher thermal insulation can pay off again by the later savings in energy costs. Should it be a sunscreen? Do you want roller shutters on the dormer? The wishes also mean extra costs.

It will also be more expensive if the roof does not have the minimum inclination of 35 or 40 degrees. Then, when installing a dormer, additional work and materials are needed to ensure rain protection - the conditions for the drainage of water are different here.

Which tiles is the roof covered with? If expensive materials such as slate are chosen here, the roof covering of the dormer will also be above the average price. Because the picture should be optically consistent at the end - the cover must be continued on the dormer.

How dormer costs can be reduced

But there are also ways to minimize the costs of installing a dormer. If you have no special requests, you can fall back on a prefabricated dormer: industrially prefabricated, they are the cheap ones. Even the time of installation can help: If the roof itself is still under construction or the attic is not yet developed, the construction project together with the dormer window is usually cheaper. It gets more expensive with finished roofs and attic floors that have already been upgraded.

Especially when the attic itself is not finished, the installation of the dormer can be combined with energetic measures. There are various subsidies from the Kreditanstalt für Wiederaufbau and the Federal Office of Economics and Export Control. If the construction project complies with the regulations of the EnEV, subsidies (for individual projects up to 10 percent of the eligible costs) and low-interest loans are possible. Who wants to apply for this funding, must:

  1. consult an energy efficiency expert
  2. carry out renovation and installation
  3. Apply for subsidy

Own contribution and self-construction are no alternative in a dormer to reduce costs. Because the work should be left to the professional, since statics and CO depend on the correct execution.


The cost of a dormer is not always low. But the purchase of the dormer is not enough. It needs planning in advance and also the installation devours money. Anyone who also has special requests drives up the costs. But with some tricks they can be kept low.

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