the cheapest way I have found so far to make some scenery is by using foam card, it glues easily and can be indented with a pencil so that brick patterns can be picked out by dry brushing. As yet I have not completed any windows and I am undecided as to wether they should be stuck on the card or cut out and represented by painted black card...
By painting a lightr brown on the card first a mortar effect can be produced (there is an excellent guide on someones blog but I forgot which one-sorry). Next step is to cut a base (I have lots of plywood though I know that it should really be mdf for neatness), and then the windows and roofs.
If one wanted to create a dedicated board then a very atmospheric effect could be produced by using darker tones-dark brown instead of red for the brick etc-but these are for general use and will have to do for now.
Any suggestions for windows would be appreciated though I suspect that in time I will make a mould and use "stick on" windows and doors, has anyone done this? Is there a guide?