[0001] The invention relates to a dormer window.
[0002] Dormer windows are known in many shapes. They are placed on inclined roofs to increase
the space under those roofs and simultaneously provide a window, which is often provided
with a casement window that can be opened.
[0003] Dormer windows exist in prefab embodiments, but are generally built up in situ with
parts made to custom. Particularly the variation in roof inclination plays a part
here. If the dimensions of the dormer window could not be adjusted, it could happen
that the window and the upper wall of the dormer window are in planes that deviate
from the vertical and horizontal, respectively. Such adjustments require a lot of
skill and time.
[0004] An object of the invention is to improve on this, to which end a dormer window is
provided comprising an upper wall with a front edge and a substantially straight rear
edge which has to connect to the roof plane, an upper side and a lower side, side
walls and a front wall in which a window is accommodated, the lower side of the upper
wall having a portion which, when seen in a vertical plane of cross-section perpendicular
to the front wall, has a concave circular course.
[0005] In this way there is freedom in the placing of the window, particularly in its vertical
aligning, without having to alter the dimensions of the window. For instance after
the actual placing of the dormer window, but before the placing of the window, the
wanted location of the lintel of the window within the concave portion of the lower
side of the upper wall can be determined and after that the window can be set at a
desired angle. A deviation in the angle of the inclination of the roof from the usual
values can thus be corrected for the window in a simple manner.
[0006] Preferably the concave portion extends over an angle of at least 20°, the concave
portion being situated at an arc angle of 35-55° from the rear edge. In this way the
concave portion is situated in an area which connects to the range within which the
roof inclinations are mostly situated.
[0007] Preferably the concave portion at least almost connects to the front edge of the
upper wall, the front edge being situated at an arc angle of over 35-55° from the
rear edge. Moreover in this way there is the possibility to place the window forwardly
and upwardly inclined, for instance like in a ship's pilot house. In this way a better
view can be obtained of the nearest part of a garden. Also -in case of a window to
the south- the projected surface which lets through sunrays is made smaller.
[0008] Alternatively there is also the possibility to choose a rearward tilted position
of the window, as a result of which the upper wall forms a kind of awning.
[0009] According to a further preference the concave portion at least almost connects to
the rear edge of the upper wall, as a result of which a stronger rearward inclined
position of the window has become possible.
[0010] Maximal freedom of choice in the position of the window is obtained when the concave
portion extends at least almost from the rear edge of the upper wall to its front
edge.
[0011] Preferably the upper side of the upper wall is substantially formed the same as its
lower side. This offers advantages as to manufacturing, but also more distinction
from the straight roof inclination, as a result of which the dormer window becomes
a striking object and adjustment to the roof inclination is seen as unnecessary, which
entails more freedom in design and installation.
[0012] Preferably the side walls in side view on the dormer window taper from top to bottom.
In that case the side walls preferably have the shape of a segment of a circle, such
as the shape of a cake wedge.
[0013] Preferably the centre of the circular portion of the lower side of the upper wall
is situated in the area of the lower end of the side walls.
[0014] Preferably the front edge and the rear edge of the side walls mutually enclose an
angle larger than 35-55°, so that the front edge intentionally tilts forwards and
the side wall can form a sideward screening for the space directly outside, in front
of the window.
[0015] According to a further development of the dormer window according to the invention
it is furthermore provided with a placement frame or parts thereof for placing against
it of a casing of the window, the placing frame being attached in an adjustable manner.
In this way the resident can if necessary adjust the inclination of the window afterwards.
This can be particularly advantageous when the house is sold.
[0016] Preferably the window comprises a casement window with a horizontal hinge axis, such
a pivotal window or an awning window. Tilting the window can then not be negatively
influenced by an inclined position of the window.
[0017] The invention will now be elucidated in the basis of a number of exemplary embodiments
shown in the attached figures, in which:
Figure 1 shows a schematic, perspective view on a roof, on which two dormer windows
according to the invention are placed;
Figure 2 shows a vertical cross-section through a dormer window according to the invention,
in one position of its window;
Figure 3 shows a vertical cross-section through the dormer window of figure 2, now
however with the window at a different angle, and
Figure 4 shows a vertical cross-section through the dormer window of figure 2, with
yet another window angle.
[0018] In figure 1 an inclined roof 14 is shown, on which two dormer windows 1 and 10 according
to the invention are placed. The dormer windows 1 and 10 substantially have the same
form, but in dormer window 10 the window 22 is provided with fixed casement windows
and it is tilted somewhat forward, which will be further gone into later. In the dormer
window 1 the window frame 9 is arranged vertically, whereas moreover there is question
of only one window with a pivotal window 11, which hinges about hinges 21.
[0019] The dormer window 1 comprises two side walls 7 and 8 with the shape of a segment
of a circle, with a straight front edge 24 and a straight rear edge 23, which enclose
an angle γ of in this example 55°. The angle of the roof plane 14, in the figures
2-4 indicated with α, usually is 35 to 55°, and in this example is about 45°. As a
result the front edge 24 of the side walls 7 and 8 leans forward. The upper edge 25
of the side walls 7 and 8 is circular, and offers support to the upper wall 2 of the
dormer window 1. The upper wall 2 has an upper surface 3 and a lower surface 4, which
in this example have the same course as to shape and -considered in cross-section-
have a circular course. As a result the upper wall 2, at least its lower surface 4,
forms a straight circle-cylindrical plane.
[0020] As suggested in figure 1 the side walls 7 and 8 can diverge somewhat slantingly to
the outside with respect to each other, in which case the upper edge 25 will of course
not be perfectly circular, when the lower surface 4 of the upper wall 2 is indeed
straight-circle-cylindrical.
[0021] It can be seen that the upper wall 2 extends beyond the window 9 to the outside,
so that a kind of awning 5 is formed, which constitutes the upper limit of a space
which is limited at the side by the protruding portions of the side walls 7 and 8.
[0022] In figure 2 a similar dormer window is shown in cross-section, with a pivotal window
19, with a hinge 21. The roof tiles 16 which lie on the roof plane 14 are schematically
shown, in which at the top a concealed gutter 27, which is integrally formed to the
upper wall 2, reaches until under the tiles 16 to protect the transition at the top
between the dormer window 1 and the roof plane 14 against water. At the lower side
of the dormer window this is taken care of by means of a (counter) flashing 26. A
batten 29, a draught sealing strip 30 and insulation 32 are shown here as well.
[0023] In figures 2-4 the rear edge 23 and the front edge 24 of the side walls 7 and 8 are
schematically shown. Furthermore a casing 20 for the roof opening is schematically
shown. Moreover a positioning frame 17 can be seen, with lintel and two side battens
which are attached to the upper edge 2 and the side walls 7 and 8 respectively. A
window casing 15 has been placed against the positioning frame 17 after that and attached
to the side walls 7 and 8 by means of screws 36. In figure 2 the positioning frame
17 is placed in the vertical plane V at mounting, as a result of which the casing
15 is situated vertically as well. In case of an angle α of 45° the angle γ between
the window plane and the roof plane is also 45° (90°-α).
[0024] Between the lintel 15a and the lower surface 4 of the upper wall 2 a sealing putty
31 is arranged. The positioning frame 17 with its two battens also constitutes a finish.
The sill 15b of the casing 15 is provided with a round recess 33, into which the circular
round upper side 34 of an upright finishing or sealing board 18 extends. Said round
upper side 34 is situated somewhat over the centre of the circle determined by the
lower surface 4 of the upper wall 2. The curve of the round upper side or bearing
plane 34 has a centre that coincides with the centre of aforementioned circle of the
plane 4. In this way the casing 15 can be rotated in the vertical plane about an imaginary
hinge axis S, which goes through said centre. As a result the casing 15 can be set
at various angles, without its vertical dimension having to be changed or the sill
having to be moved in the horizontal sense. This versatility makes it possible, if
so desired, to place the window vertical in situ with only very simple actions. The
round upper side 34 of the board 18 here forms a reliable and defined rotation plane,
so that the board 18 here functions as indication of the location of the centre and
the sill 15b, which facilitates the correct placing of the positioning frame. The
board 18 moreover provides a sealing to the outside.
[0025] In figure 3 a situation is shown in which the location where the sill 15b supports
on the round support plane 34 is rotated more forward. The positioning frame 17 is
first placed at an angle β1 with regard to the vertical V of approximately 10°. The
angle γ is more than 55°. So in this case the window casing 15 leans forward, somewhat
similar to dormer window 10 of figure 1, so that one can have a better view on the
space below, such as a back garden.
[0026] However, it is also possible to have the window take a position which deviates from
the vertical, so that a special effect is obtained. A second example thereof is shown
in figure 4, in which the positioning frame 17 is pivoted far to the inside, and in
front of the window casing 15 a deep kind of awning 5 is formed, in which the lower
surface portion 4a is situated outside of the window 15. In this case the angle γ
between the rear edge 23 or the roof plane and the window is about 20° and as a result
the angle β2 between the window 15 and the vertical is about 25°.
[0027] Ease of installation is for that matter increased when the flashing 26 with the rear
edge is laid over the round upper side 34 of the board 18 in order to be clamped with
it to it by the sill 15b.
[0028] Should the resident wish to change the position of the window at a certain moment
in time, he can rotate the casing 15 into the wanted position after having it detached
from the frame 17, the plane 34 forming a kind of roller bearing, and afterwards secure
these parts again.
1. Dormer window comprising an upper wall with a front edge and a substantially straight
rear edge to be connected to the roof plane, an upper side and a lower side, side
walls and a front wall in which a window frame is accommodated, the lower side of
the upper wall having a portion which, when seen in a vertical plane of cross-section
perpendicular to the front wall, has a concave circular course.
2. Dormer window according to claim 1, the concave portion extending over an angle of
at least 20°, the concave portion being situated at an arc angle of 35-55° from the
rear edge.
3. Dormer window according to claim 1 or 2, the concave portion at least almost connecting
to the front edge of the upper wall, the front edge being situated at an arc angle
of over 35-55° from the rear edge.
4. Dormer window according to claim 1, 2 or 3, the concave portion at least almost connecting
to the rear edge of the upper wall.
5. Dormer window according to any one of the claims 1-4, the concave portion extending
at least almost from the rear edge of the upper wall to its front edge.
6. Dormer window according to any one of the claims 1-5, the upper side of the upper
wall being substantially formed the same at its lower side.
7. Dormer window according to any one of the preceding claims, the sides in side view
on the dormer window tapering from top to bottom.
8. Dormer window according to claim 7, the side walls having the shape of a segment of
a circle.
9. Dormer window, the centre of the circular portion of the lower side of the upper wall
being situated in the area of the lower end of the side walls.
10. Dormer window according to claim 8 or 9, the front edge and the rear edge of the side
walls mutually enclosing an angle larger than 35-55°.
11. Dormer window according to any one of the preceding claims, furthermore provided with
a placement frame or parts thereof for placement against it of a casing of the window
frame, the placement frame being attached in a adjustable manner.
12. Dormer window according to any one of the preceding claims, the window frame comprising
a window with a horizontal hinge axis, such a pivotal window or an awning window.
13. Dormer window comprising one ore more of the characterizing measures described in
the description or shown in the drawings.