Extrude surface so it follows direction of adjacent sides

Im pretty new rhino user and i come across one thing that bothers me a bit. I would like to be able to extrude a surface of a solid so that the surface grows or shrink in line with the adjacent sides. Im an architect so I draw slabs a lot. In archicad that I used earlier this was a breeze, but do someone know if there is a simple way to do this?
Waht I do now is that i first extrude, then I have to move the vertical edges out in line with guidlines of the adjacent sides. Se picture.

Extrude is the wrong command for that.
I would try a 2d Scale using a back corner as the base point.

Rhino 8 is able to do that with Push-Pull modeling.

https://www.screencast.com/t/qxSacXyNTaaR

(the clipping you see in the viewport during the preview is already fixed in the current WIP)

4 Likes

Ah thanks, that worked, at least for this triangular slab. But it does not seem to work when its more sides involved, at least not in the way I would want it to.

Good news!!