How do you extrude a shape without outer faces and edges? [duplicate]

Question

In Sketchup, if have a shape that I want to cut a section out of, I can use the pencil tool to draw an area and then extrude the area down (using the push / pull tool). The outside edges are removed:

In Blender, I'm trying to do the same thing but it isn't working in the same way. I used the Knife tool to draw the area I want to remove and extrude down, but the outer edges are still remaining:

I haven't yet figured out a way to manipulate the mesh to get the desired result after this extrusion.

Is there a faster / better way to do this in Blender? Is there a tool that behaves similarly to Sketchup's push / pull tool?

Answer 1

Edit: As Nicola Sap says it's now available in Blender, AltE > Extrude Manifold.

You need an addon to do that with the previous version, Blender Destructive Extrude:

https://www.youtube.com/watch?v=beZau_wpR-U

https://gumroad.com/l/cQjUX

or you need to delete and fill some faces, or try to extrapolate before modeling.

Answer 2

This feature has just been added to Blender.

It will be available from version 2.90(https://builder.blender.org/download/).

It's called "Extrude Manifold" and is located in the toolbox T, under the "Extrude" dropdown, Or by pressing Alt+E.

^{↑ Here I'm using Face select mode (3) but it works in vertex select too}

Answer 3

Unfortunately this feature is lacking in blender. You've got two options here - move all the faces down and only extrude the ones you want higher upwards. This would work fine in your case.

Alternatively you can delete the faces you don't want - this option is for when it doesn't work out with the first method.