story and a half apartment over garage roof and ceiling

[SunnyDay]

I'm new to Home Designer 2026 and love the software so far. I have run into an issue trying to create an apartment over our garage. I'm working from an existing structure that we are renovating. After several tutorials and five versions I have a flat ceiling over the room but the top ceiling height is still a little too high. I have started documenting all of my selections in properties but do not know what I selected to case the under roof to have no sheetrock or the gaping hole that extends along the edge of the roof.

Can you help me identify the error here? 

Are there any story and a half templates that are editable in Home Designer 2026?

Any suggestions? 

Thank you in advance for your help.