ᐅ South Terrace: Glass Roof with an Overhead or Underneath Retractable Awning?

Hello everyone,

we are currently planning a glass patio roof with a glass windbreak on the west side. The roof measures 4.5 m x 4 m (15 ft x 13 ft). Would you recommend a top-mounted or an under-roof awning?

Thank you for your suggestions!

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

There is definitely a difference in terms of heat! I only know this for roof windows, where it clearly matters whether the shading is on the inside or outside. We have, in addition to an internal blackout blind, an external sunshade blind. The external blind is made of a fabric that still lets some light through but provides better heat protection than the blackout blind.

This is because it gets very warm between the internal blind and the windowpane, and that heat then warms the room. It is similar with a glass roof, although I believe the other advantages of the canopy type sunshade on the glass roof outweigh this.

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

As a result, the temperature under the roof is not higher than the surrounding air.

The advantage is that the awning fabric/material is protected. The disadvantage is that the top surface is difficult or even impossible to clean. Over time, dirt (insects, dust, etc.) will accumulate there. If necessary, you can try blowing air into the gap with compressed air.

Roofing. Shading should always be installed on the exterior. It might work with some roofs, but I have also experienced heat build-up on terraces with under-roof awnings.

The answer, as someone has already mentioned, depends on the situation:

If the side walls are closed... roof underlay is recommended, because the air cannot escape, leading to heat buildup.

If the side walls are not closed, I prefer roofing membrane. It makes no difference in terms of heat since the air can escape. Additionally, it looks better, and the awning stays in good condition much longer because it is better protected.