You're welcome =)
Perspective and proportions: the (square) floor tiles appear half as 'deep' as long (16x32), so any horizontal figure should be shortened by 1/2 in apparent depth. Supposing the wall top bricks upper faces to be 'really' 16x32 px, they should appear 8x32 when facing, and 16x16 from the side. You may probably cheat a few pixels, but for some reason I think consistency should be maintained because of the iso floor tiles, more than on obviously impossible persps like Vierbit's.
What he does defeats understanding! There are several types of strong 'inconsistencies' and I have no idea how he gets away with them XD
First, the strictly top-down floor (in most cases) vs ~45° buildings; most secondary horizontal planes (parallel to the ground) are not strictly top-down (square) though, for instance pillar bases and tops in the top left piece.
Some of the pieces with sideways floor tiles are not strictly top-down either, and he even gets away mixing the 2 types of floors in 2 pieces!
2 other pieces on the 3rd row have 'rolling' perspective, starting from top-down tiles at the bottom and more or less gradually easing into a level view with vanishing point into the distance.
A strategic use of detail is probably key; for instance in the 3rd row, right piece, notice how the tiles are replaced with big swaths of floor and then nothing, leaving the persp transition hard to pinpoint.
Colors: I see the doors as bluish grey, not white. It's more a point of recycling though as those blues appear nowhere else, and none of the wall teals are used in the doors. But white/light grey with teal shading would be nice, I think.