How to cut a quadratic hole into a face of a mesh?

Question

I am modelling a house in Blender and want to inset the windows. To do that, I thought I would cut out a quadratic hole from the middle of the plane, then extrude the new vertices and create a face from the extruded vertices. I have tried several methods to cut out that hole - using the Knife tool, using a Boolean modifier on the House with a Cube as target, etc. - but all either did nothing, or created two edges between some vertices of the hole and some vertices of the face, like this:

I want to get the above, but without the edges and vertices surrounded in red - I waant to keep only the four vertices (and connecting edges) circled in white. Can this be done ? Please help quickly.

Answer 1

This is a duplicate question, but it’s almost not worth looking up. It’s the hidden basics of 3-D that you cannot cut a hole in a face. In fact, even blender 3-D engine is faking a bit, since it allows you to create faces with more than three vertices. In reality, all this gets triangulated before being rendered. But Blender does not fake where sketchup does: sketchup allows faces to have virtual holes in them with no (visible) connecting edges, but blender stays true to the glue and does not.

What I think you should do here is create an edge going between where the two gutters of this house would be. Although this may not be necessary for your texture, it would make geometric sense, and would satisfy the no holes condition. Note that if you just select the two vertices and create an edge, you will have to select all and “weld edges into faces” for it to actually split the face.