This pattern is worked from the top down in one piece.
Mostly it is worked in the round in a continuous spiral, though the doorway is worked with decreases & increases and back and forth.

You want a nice tight gauge for a stiff fabric. There isn’t much room for a looser gauge - I just barely managed to crochet the sample in one skein!

Spray with non-toxic stiffener such as Stiffen Stuff if desired for an even firmer birdhouse.