0 a small, usually wooden, shelter for a dog to sleep in outside
1 a small shelter outside of a house for a dog to sleep in
If there's no room for me I'll sleep in the little doghouse in the orchard—I've seen it.
Maybe it was his house, although it was bigger than any doghouse she had ever seen before.
This doghouse was built at the very foot of the promontory, against the hill, and about forty yards to the right of the house.
My basic assumption is that -er forms, like noun+noun compounds such as doghouse, are best viewed as abbreviated noun phrases.
A pigsty or a birdcage would not reasonably be called a house, but what about things like the public house, the monkey house, the doghouse?
Among those at the bottom were politicians and teachers, which rather put me in a double doghouse.