No rule for this one
No ending or word group predicts the article of Haus. Learn it as a pair and say it out loud: das Haus.
das Haus
It's das Haus. Haus is neuter, plural die Häuser.
Das Haus ist alt.
The house is old.
No ending or word group predicts the article of Haus. Learn it as a pair and say it out loud: das Haus.