Meaning:
“B站” refers to Bilibili, a top Chinese streaming site, and “有房” means “to have property.” Coined by Chinese netizens, this humorous saying means that someone spends a lot of time on Bilibibli as if they had property at the site and lived there. Such a person follows many vloggers and frequently leaves comments after their posts.
Example:
A: 你平时喜欢上什么网站？
Nǐ píngshí xǐhuan shàng shénme wǎngzhàn？
Which sites do you normally visit online?
B: 我在B站有房。
Wǒ zài B zhàn yǒu fáng。
I spend hour after hour on Bilibili.