How are dormer windows mounted on the roof?

The design of the roof consists of many elements that give it an attractive and complete appearance. Although more than 90% of its area is occupied by the surface of the slope, auxiliary components that affect functionality and service life are of no less importance. For example, the dormer windows on the roof do not just play a decorative role, they serve to ventilate the truss frame and help organize vertical lighting in the attic. Despite this, their device seems at first sight difficult, the installation of windows can be done by hand, guided by the video and our instructions.


Dormer windows are glazed openings located on the roof of a building. They are equipped with a gable, hip, hip, and semi-hipped roof. The device of dormer-windows is made during the assembly of the rafter frame. Assembling a "cuckoo" with your own hands, as they are called differently, solves the following tasks:

  1. Organization of attic ventilation. The main task of the dormer windows is to open the air in the roof space. Their device allows you to constantly ventilate the rafter frame, preventing the wood from rotting.
  2. Organization of vertical lighting. Attic device involves the organization of natural lighting, which comes through the dormer windows.
  3. Providing access to the roof. Another function of dormer windows is to provide access to the roof surface in order to make repairs, installation or maintenance with your own hands.
  4. The completion of the architectural appearance of the roof. The design of the hip, hip and half-hinged without skylights looks unfinished. The installation of these additional elements makes the appearance of the roof richer and more attractive.

Consider that “cuckoos” primarily serve practical purposes, and only then decorate the roofing structure. Therefore, the size, shape and finish of this architectural is chosen so as to ensure maximum light, air and free access to the roof.

Dormer device Roof construction with dormer windows


The classic design of dormer windows is a superstructure projecting above the roof surface, which visually resembles a small house. Монтаж этого архитектурного элемента можно выполнить своими руками, если правильно сделать расчет, создать чертеж, а затем собрать каркас. Установка слуховых окон допускается при угле наклона скатов не более 35 градусов. Dormer device может имеет следующий вид:

  • With a pediment in the plane of the structure without side walls.
  • With a pediment in the plane of the structure with side walls.
  • With a pediment outside the plane of the building and with side walls.
Kinds слуховых окон

Note! The device of the dormer window must comply with building codes; its dimensions must be at least 10% of the area of ​​the attic room, but not more than 0.5 of the width of the wall on which the installation is carried out.

The form

The design and location of the "cuckoo" is chosen in accordance with the appearance of the roof and the architectural style of the building. In addition, the finish of this element should match the roofing material used to overlap the roof. Installation of dormer windows is carried out in accordance with SNiP II-26, SNiP 21-01. Compliance with these standards ensures reliability and durability of the structure. Dormer dormer window can be triangular or rectangular in accordance with the configuration of the openings. Usually one of the following types will be installed:

  1. Single-skinned
  2. Dvukhskatnye.
  3. Arched.
  4. Waltz.
  5. Flat.

Take into account, the installation of the hilar framework of the dormer window is much more complicated than a single or dual slope. Proceed to the installation of an architectural element of high complexity, with a detailed drawing in front of you, as well as the necessary tools. In order to study the installation process in detail, you can watch the video instruction.

Dormer frame

Device frame

Whatever the shape of the window, hip, double or arched, the main rule of design - the design of its frame should not violate the roof truss system. "Cuckoo" is mounted as follows:

  • First between the truss legs of the roof frame, front beams are installed.
  • On rafters, limiting the design of the width, install vertical racks.
  • At the top of each row of vertical posts a run is installed connecting the supports between them.
  • On the girders install trussed legs, which are connected to the ridge girder.
  • The frame is sheathed with siding or clapboard, and roofing is laid on the crate.

Important! It is not easy to install an auditory “nesting box” on the roof without disturbing the truss frame of the roof. To learn more about the process, you can watch the video guide or read our instructions.

The frame of the dormer window

Video instruction

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