South terrace: Glass roof with upper or lower awning?

Hello everyone,

we are currently planning a glass terrace roof with a windbreak on the west side (also glass). The roof has a size of 4.5 m x 4 m. Would you recommend a top-mounted or an under-roof awning?

Thank you very much for your ideas!

I think that an awning under the glass is more practical in that it is protected from dirt and also from rain. However, I also wonder for our planning whether it makes a difference in terms of heat?

It should make a difference in terms of heat! I only know this exactly from roof windows, where it does make a difference whether I have the protection inside or outside. In addition to the blackout roller blind (inside), we also have a sun protection roller blind (outside). The outside roller blind is a fabric that still lets some light through, but it nevertheless provides better heat protection than the blackout roller blind.

This is because it gets very warm between the inner roller blind and the windowpane, and this heat then does warm the room. It will be similar with the glass roof, but I think the other advantages of the under-roof variant predominate with the awning on the glass roof.

We have a terrace roof with VSG and an under-roof awning. If all sides (except for the house side, of course) are open, the trapped heat can escape to the sides.

Accordingly, it is not warmer under the roof than the ambient air.

The advantage is protected awning fabric/mesh. The disadvantage: the top side is difficult to clean or cannot be cleaned at all. Dirt (insects, dust, etc.) will accumulate there over time. If necessary, blow into the gap with compressed air.

Roofing. Shading always on the outside. It may work with some roofs, but I have also sat on heat-stagnation terraces with under-roof awnings.

The answer is, as someone already wrote, it depends:

If the side walls are closed... [Überdach], since the air cannot escape and this leads to heat buildup.

If the side walls are not closed, I find [unterdach] better. It makes no difference regarding heat, as the air can escape. Furthermore, it looks better and the awning stays nice for much longer because it is better protected.