Firstly, just a point to note:
The left and right of this space are internal walls.
IMAG0021 by LostInTheUnderflow posted 22 May 2018 at 12:43 AM
IMAG0022 by LostInTheUnderflow posted 22 May 2018 at 12:43 AM
I am planning on insulating the roof right to the bottom and extend the plastic sheet...