Loft lighting – which roof window should I choose?

Window manufacturers have a wide selection different sizes and shapes – horizontal and vertical windows. The size and type of them usually depends on our preferences, however it is a very important to take into consideration a few important leads which will matter during using. Window type will have a huge impact on the comfort level.

It is important to define the amount of the light. If we buy window to the bedroom which does not always require a lot of brightness, it is better to invest into bigger one and correct the excess of the light with proper blinds. Many users decide to go with the budget smaller windows which are purchased by them last minute. There could be a situation where during using we find out that our room is underlit, but then the costs of window replace is very high.

  1. Proper roof lighting.
    Natural light has a huge impact on our well-being. In well-lit rooms we simply feel better and have the opportunity to have better results at work. Bright rooms represent much higher commercial value than dark ones.
  2. Room ventilation.
    Room ventilation is not often taken into consideration during attic or annex modernizing. The purchase of a window with built-in ventilation costs several pounds and while using the room it will be well ventilated. We should remember that there are many sources of moisture in the house that can come from the outside or be generated by the household members, cooking or laundry.
  3. Comfort of use.
    One of the main criteria of window division is how the window opens due to the position of handle and axis of rotation. There are centre pivot, top-hung or access windows. Height of the room will matter while choosing which window we want to buy – bottom or top opening and centre pivot or top-hung kind. The installation height and window type will be important when it comes to visual contact with the surroundings.

Here are a few tips to follow when choosing roof windows so that every household member can feel comfortable being at the attic and using windows.

The amount of the light needed in the room is based on ratio below:

Active window area

Floor area


Room size: 18sq m (6m x 3m)
x=2.25sq m


The active window area should be al least 2.25 square meters.
In our example we can use several sets of windows.

4 x 78 x 119
3 x 78 x 98

The table below shows the active size of the window depending on the window size.

In order to achieve better distribution and evenness of the light, the best solution is to use four windows 78 x 118. We will achieve better light effect when installing windows at various points of the roof. It is better not to install windows close to each other in one place if possible.

An important parameter is also roof pitch. The smaller roof pitch is the higher the window installation should be. Window installed higher gives more light.

The height of window installation.
Recommended height of window installation is 110 – 140 cm (bottom edge) from the ground.
Recommended height of top edge is about 200 – 220 cm.

Steam condensation.
To avoid steam condensation on the glass it is recommended to install a heater under the window. It will assure proper air circulation which will reduce steam condensation.