UNITED STATES—Modern detached houses are often very reserved in their form. The cube shape with a flat roof does not exclude installation of roof windows. What are the benefits of using such a solution and what are the functions of windows for flat roofs?

Flat roof does not exclude installation of roof windows. Modern technological solutions allow for incorporation of glazing also in such structures. Letting natural light in through the ceiling is important not only because of the aesthetics of the interior. Choosing the right windows will also support the energy efficiency of the building.

Windows in a flat roof – a source of natural light

So far roof windows have been the solution reserved only for pitched roofs in houses with adapted lofts and attics. The idea was to let natural light into the interior where it is impossible to install windows in the wall. A window in a flat roof can also act as a hatch, which is essential in this type of construction.

For buildings with a flat roof, the situation is a little different. Flat roof windows are a way to add extra light to rooms with northern exposure. Such interiors receive the least amount of daylight through north-facing windows. In the summer these areas are slightly cooler, while in winter more thermal energy will be needed to heat the room. If the room is located on the top floor, you can use flat roof windows to bring more light into the interior.

The trend towards open spaces sometimes creates problems with even lighting throughout the interior. In this case you can also use roof windows. By placing a glazing in the ceiling you can bring light to spaces where light from windows in the walls does not reach. Flat roof windows can also provide natural light to staircases and rooms situated in the central part of the building, e.g. bathrooms or dressing rooms.

Choosing the right windows for flat roofs

Installing roof windows is very different from installing windows in wall openings. Naturally, the construction of a flat roof window is also different. The glazing may consist of up to four panes. Some models of flat roof windows are additionally equipped with a glass dome, which supports the thermal insulation properties of the structure.

Assuming that more natural light in the interior is supposed to generate electricity and heat savings, you need to choose energy-efficient windows. This will be indicated by the Uw heat transfer coefficient. Windows for flat roofs, for which this coefficient is 0.64 W/m2K according to EN 12567-2, are intended for energy-efficient and passive buildings. Such parameters can be found in e.g. Fakro F-type windows for flat roofs.

Favorable energy efficiency coefficients allow for the use of large glazing in the flat roof, which not only provide more light to the interior, but also have a positive impact on the aesthetics. Windows for flat roofs are an attractive finishing element of a modern house.