Roof windows
They are an ideal choice for two reasons in principle for the light that we won in the environments and decorative benefits has natural lighting. Moreover, because they can reduce energy consumption and environmental and economic benefits at that point.
In the picture we are seeing an option from the company Velux in roof openings. This is a roof window powered by solar energy, which converts solar energy into electricity through a photovoltaic cell located (in a practically invisible) at the top of the window.

According to various studies, proper placement of these windows allow solar heat gain and to identify adequate ventilation, generating a home energy savings in approximately 30% compared with the use of traditional systems.
Decorative level, earn several points regarding interior lighting, spacious feeling of space thanks to clearer and stronger external-internal relationship, by a direct view of the sky or surrounding landscape. Three items that can completely change the aesthetics of an area, be it a loft as a room located in an upper floor.
The dormers above have a power saving function that includes variables that take into account the local average temperature, orientation of windows, location and other points, so as to advance an agenda that blinds down or up depending of the season and time of day.