Mark3D

Also turn on attick walls there is one that messing with that intersection I found the problem went away when I deleted the attick walls if this is a suitable thing to do

To start with the file uploaded has no foundation so maybe its the wrong file, Jims screen shot show what to adjust.

Its seems to work fine for me, you are not changing the defaults instead of the individual garage rooms, or are you selecting the spanner after setting the negative height.

Try watching some videos there are heaps on you tube also chief website have more just not sure you can access them if you are using x15 may be SSA is not current. there is a note in the plan file attached plan file 264014205_3roofandporch.plan

Had a go its not perfect but maybe good enought with some manual editing 264014205_3roofandporch.plan

Steps to rotate

Watch this video https://www.chiefarchitect.com/videos/watch/10119/using-the-adjust-material-definition-tool.html

It is x17 only but x16 this should work

3D Menu-Adjust Materials-Interactive material Editor in standard camera view

it should look like =count*0.15 you are missing the zero before .15

Is this what you want blue house with porch roof help.plan

Share your plan file

I can have a look for you if you like I will send you a private message

Sorry i did not read your first properly, I do not how to help with over framing its adding complexity that I have little knowledge off

See if that model is cleaner and closer to what you want. you need to not place roof plains on top of each other with out cutting and joining to each other if it is what you want i can do a video show how I did it, also I change the rafter sizes to 6"not what size you want but 9" seemed to big to me not sure thought and causing some gaps Roof Frame help.plan