roofing assistance please

try again

https://i.imgur.com/occtmKB.png

https://www.youtube.com/watch?v=SF4xs5N4HQU

That sadly wont work, if the none diagonal part is an uneven amount of tiles wide, like in your case.
So for your Problem this is better:

Place the octagonal roof (pink)
https://i.imgur.com/KHyMH6f.png
Make it the correct size
https://i.imgur.com/mJgHXe7.png
Lower it to the prefered size and add the gabeled roof (blue)
https://i.imgur.com/UUNzZ35.png
Make it the correct size
https://i.imgur.com/07EJUcv.png
Lower it (blue) down to the octagonal (pink) height
https://i.imgur.com/VgDcGgZ.png
Make the gabeled roof one tile wide and pull in the overhanging part on the sides
https://i.imgur.com/BtgKVx8.png

How it looks like with glass roof:
https://i.imgur.com/k0DKNRX.png

thank you so much @crysk. It looks so polished!