using acad 2012. In previous versions i used regions for identifying walls in models. The benefit of this was in shaded mode. The side would only shade to which the z axis was applied. When viewed from the other side it would appear transparent - enabling the model still to be seen. In this version both sides shade. Does anyone know if a setting is available to make the reverse side transparent.

typically i will have a steel staircase surrounded by walls. In shade mode if the walls were solid then the staircase would not be visible. A good way then is to have walls made from regions. As i have stated, in older versions, the back of regions were transparent so as you rotated the staircase the nearest walls were transparent and the far walls solid. This is a good visual tool. Unfortunately in 2012 both sides of the regions are solid hence the staircase is not visible. Is there a setting to amend this? Draw a region and try it yourself you should understand

Look into the use of Xray visual style and/or the use of transparency as it applies to layers and objects.