QUESTION:

How can I easily alter the geometry of a pitched roof ?

ANSWER:

Even though the pitched roof object looks a bit primitive, it is actually relatively quick and easy to assemble even quite complex roof systems. The trick is to keep the roof object grouped so that when you select one node, you move all other coincident nodes at the same time. You can quickly get into trouble if you try moving each component of the roof separately. Rather than try to explain it here, there is a quite comprehensive description on manipulating roof objects in the "Simple House" tutorial that comes with ECOTECT.