宅 is another word for 冢 or home. Five thousands years in Chinese culture, no one will use 宅 by itself, it has to be grouping with another word or words to mean something.
You always hear 宅 was spoken by people. I bet, they are non- Chinese or this question has been prefixed with answer. For example: Ms Courtney's answer is " always stay at home" . Here, she use more than one words, instead of the word 宅 by itslelf. I would argue, it means "always not stay at home" 他常常离宅". Moreover 我很宅, it is a colloquial, not everychinese would understand.
I think, you already got the answer, "宅", the Chinese speaking people will not used it without grouping with another word(s).