I've wanted 1 sided walls for some time. The only work around I can think of is inefficient. Basically it'd be a setup of command blocks and spawn blocks.
The way I'd do it, is place spawn blocks on the wall where you have those 2 sloped blocks. Then put expandable CMD blocks on each side of them that loop every time they're touched.
Off to the left side (judging from the prespective of your video) of the building, in the CMD block write,
for nearest block (Block ID) delete (create a custom block with a blank sprite you can't see, with any dimensions you choose, preferably 32x32 like your invisible blocks, oh, be sure to delete your invisible blocks as well, and don't type this into the command block, this is just a note)
Then in the other CMD block on the opposite side of your invisible blocks which you should remove, as they'll do nothing but cause probably worse glitches than before, write,
spawn block (Block ID) , (Spawn Block ID)
You may have to add more expandable CMD blocks around the area as needed (like below the new spawn blocks) in order for your character not to glitch with the new blocks.
