This is about optimizing living space. As I wrote, I am subject to building regulations. I am allowed a maximum height of 2.3 m from the top edge of the raw floor to the outside of the roof in this area so that this area does not fall under the full storey definition. You can see this in the 3-D model that I attached. A full storey is not allowed. At the same time, the room under this area should count as living space, so it must have a clear room height of >2.0 m. A normal roof with sufficient insulation is not feasible with a thickness of <30 cm. Unless someone has a creative idea :) Expensive aerogel insulation panels are another consideration. I gain about 30 m² of living space which corresponds to a property value of 270,000 euros at a price of about 9000 euros per m² in the area. Thermal insulation is not a problem; there are glass configurations that sufficiently block both heat and radiation. Darkening can be done with internal pleated blinds or blinds between the glass panes, etc. All challenges are solved so far, except possibly the rain noise. Which maybe isn’t so bad if someone can report such experience. A 1010.2 st - 14 - 8 - 14 - 88.2 st glass configuration insulates about 53 dB sound. But that results in a heavy overall glass construction of about 7 cm. Unfortunately, the architect is uncreative :(