Not really sure under which topic this should fall as it involves both insulation and building techniques. The house was extended in '54 with a garage on the basement level, a room, and a terrace as shown in the picture. The red area is the terrace. In the attic that extends all the way, there are currently wood shavings. In the future, we might consider enclosing the terrace with glass to extend the time it can be used. However, it will probably never become a heated space more than temporarily with something like an infrared heater.
The current construction feels strange and if you want to build a loft in the attic, how would you do it? Any spontaneous reactions or tips?