While many people are only taught one reason for a silent E, there are actually many different jobs that a silent E may be doing in a word. Only about 50% of silent E words have the E for the purpose of making a vowel say its long sound.
Here's a clue about this one: Does "hous" look like a singular noun?
No, it looks plural. So we add an E: house. This silent E job is described in Spelling Rule 12.5: Add an E to keep singular words that end in the letter S from looking plural.
Some other words that follow Rule 12.5: horse, praise, release, pause, verse, goose, eclipse.
Learning all the different reasons a silent E may be present in a word equips students with powerful tools to understand English words and eliminates hundreds of so-called exceptions! To learn more, check out Uncovering the Logic of English: A Common-Sense Approach to Reading, Spelling, and Literacy or Logic of English Foundations or Essentials curriculum.