Newbie Question - About the surface interactions (intersecting surfaces)

When I try to push/pull the Rectangular surface ( for a window ) on to the inside edge of the drawn wall it wont cut out the portion of the window

When I previously tried to do this - there were never any problems.

I assumed that this is happening because of the inclined angle that the model makes on the horizontal plane. (REFERRING TO THE SECOND IMAGE)

Usually the reason is that the involved faces are not quite parallel.


i suspect that all but the top edge of the
rectangle are not on the wall face== where they all need to be for that operation.


I rotated the model w.r.t to the inclined faces, and turns out many of the edges weren’t properly aligned to the axes.

(I thought of this but ruled it out of the equation as I thought that it had a deeper underlying problem)

Thanks once again.

Have a look at this, Aaron explains it well.