First off that's for the advice.

To answer Midgardsormr, I'm using Photoshop CS3

So this is what i just tried like 5 minutes ago,

I created a copy of my wall layer
On the west window, grabbed a window from dundjinni and snadwiched it between those layers.
On the north window I tried the suggestion that Bogie made about drawing lines.

I might take a crack at eh lighting later after I look over that file, I've only really done underground maps and really never had to consider anything other than shadows.

Council Tower - Layers copy.jpg