I suffer from the same issue, but there are ways to minimize the work.
The shadows don’t have to be spot on. You can rotate the house about 45 degrees to either direction without a need for redoing them. But the need for changing the light direction still exists.
I have created all the houses in one PS file where all similar items of every house are in the same layer. I mean all roofs facing one direction are in one layer, all roofs facing other direction are in another layer and all chimneys etc. are in yet in another layer.
By changing the direction of the global light source you change all drop shadows and bevels at the same time. Then you just need to change the exposure of the adjustment layers to get the roof shadows right.
It takes just one minute to make all the changes and it applies the changes to all of your houses in one go.
If you could invent a way to do the roof lighting in a way that it would rely on PS global light source as well, the problem would be solved. You could have all your house layers in your map file itself and you could rotate them as you like and the lighting would work.