The only way I could think to add height but not weight to the roof was to glue braces to the bottom layer, (the original kit roof,) and then cover them with a sheet of 1mm plywood. I cut a load of 6mm MDF blocks and gave the roof a new spikey hairdo
It does the job, strengthens the roof and leaves space in between to hide all of the electrical gubbins.
To make the cladding boards match the same lovely curve of the roof, I used the end profile that you get with the kit as a template to cut around.
Once they were all painted and glued into place I cut a piece of card, which I will use as a template for the final piece.
Next - building kitchen cupboards...oh and cleaning my kitchen. Damn it's messy in here.
Have a fab weekend