I have a cake order from a friend, that wants a cake to look like the restaurant where she works. (from the outside of the building only)

Chances are, it will be a sheet cake, layers, to make the rectangle shape of the restaurant, with buttercream.  How many layers do I need?  And how do I make a roof and how do I make it stick?

Should I do the windows, awning, front door in fondant, and put them on, or use a tip with buttercream.

All suggestions are welcome...believe me, I need them.

Thank you in advance!

Hi joyfullnoize, I am new here, so what I say may not be correct. But just thought you can use fondant as tiles (or chocolate tiles) for the roof.

google images for house cake and there are loads of them to get an idea.

windows and doors of fondant/gumpaste will look better than piping and give you the choice of playing with their design. 

thank you for your help.  It is appreciated.  I will use google.

Since the only interesting side is probably the front of the restaurant, I don't think it has to be a rectangular or square building cake.  You can do the square thing , or do a round cake with a built up restaurant scene.  Either way looks great, but using the round approach lets you do a blue sky and other touches that I think add a lot

Another great idea!  Thank you!