Easy way - insert a box object in the wall (disable magnetism) a few mm deeper than the wall. Add your favourite oak texture.

After several versions of the same construction project, that I drew in Sweet Home 3D, this is the first time, that I have disabled magnetism. Needless to say.., not more was needed to solve my problem. I am almost ashamed but thank you so much for the hint !

A slightly more challenging would be to design your own window in Blender, Art of Illusion, Sketchup or whatever, include the lintel, read up on the advanced properties in the Furniture Library Editor... etc. [:)]

Yes, but I chose to tear the simple texture-less box into shape and apply the photograph of a real oak beam to it. Actually, this frugal box has served me several times, already... It is a girder, floor-, ceiling- or roof-beam, a threshold where other solutions are too complicated.

On a very practical note, please be careful if you are about to add the oak beam as a lintel to an existing wall physically. Messing around with structural elements of a house can be risky - and certainly much harder than adding the lintel in SH3D...

A brick has hit me over the left eye, when we finished a door-opening. Having hoisted another window-lintel up on one side of the opening, I noticed that on the other side a stone protruded from the wall and prevented me to install it. The oak beam on the left shoulder, I operated the side-grinder with the right hand until the monster fit in smoothly.

No, that is not what I want to do for the rest of my life, but I am either harder than I had thought in the beginning or just very mad by now. Both help. [8-}]

Thanks again, also for the example in the PM.

Michael