Building Doors, walls vs boulders

[Brygun]

I;m plannng Tuukka's first winter building

There is spot with a bouldder, 2 gaps, boulder. I' wondering if I can get a door in the two gap space.

such as:
b = boulder
D = Door
W = Wall

bDWb

Or does the door require walls on both sides?

[JP_Finn]

I’ve not tested boulder as door frame support, but cave wall works in your sampled layout.
It shouldn’t take more than 1/2 day of Tuukka’s time and 6 logs & 8 boards to test.

I’m about 99.999% sure that you can’t use boulder wall room as smoker.