About windows and daylight
There are a number of aspects you should bear in mind if you decide to put windows in your façade or roof:
- Type of window: Do you need large windows, for example, or small ones? And should the glass be Double Glazed.
- Window position: Should the window be placed low down, or right the way up the roof ridge? Do you want windows on one side of the room, or both sides?
- Permanent sunscreen: Would it be good to add blinds?
- Surrounding buildings and trees: What features are there around the home that may block out the light?
Window type
First and foremost, study carefully the many different types of façade window and skylights. The best alternative to dark rooms is good quality windows which use low energy glass. Insulating glass, for example, is a really good investment. Always check the U-value and SHGC (Solar heat gain co-efficient) measures of thermal performance for the entire unit, including glazing and frame. Its often the framing which is the weakest link for insulation.
The amount of daylight passing through a pane is reduced for every additional pane of glass through which the light has to pass. For example, a two-layer glass pane allows approx. 80 % of the light to pass through. This does not mean that you will notice having less light indoors; but if you are directly in the line of the sunlight from the window, you will feel less hot. At the same time, the multiple layers of glass maintain the heat indoors. All in all, insulating panels provide a more pleasant, more practical indoor climate.
VELUX Skylights and Roof Windows are fitted with Double glazed, low energy glass as standard. The special E2 coating is designed to allow through as much light and as little heat as possible, resulting in a more pleasant indoor climate and only a small amount less light.
Window location
The location of a window in a façade or roof plays a big part in both the quantity and the quality of the daylight which the window lets in. The higher you place the window, the more light in the room. And the more daylight and sunlight you bring into your building, the less artificial light will be required.
Skylights can be fitted anywhere in the world. If you would like to bring in masses of sunshine and light through the window, north-west is the best position possible for the Southern Hemisphere as this allows light in most of the day and on into the evenings. If the skylight is to be set high up, it is a good idea to buy electric windows. At the same time, as a rule of thumb you should estimate that the strength of the light is halved for every metre it penetrates into the building.
Screening against light and heat
Blinds provide more opportunities for regulating light and shade – and for keeping the warmth in, on a cold winter day. There are blinds operated mnually but also by electricity or solar power, blinds which provide insulation against heat or cold, and blinds with a range of other functions.
Trees and buildings
Tall trees and buildings limit the incidence of daylight. If you want to fit a new window in your home, therefore, you should look for a position which is not overshadowed by the surroundings.