Assalamu alaikum warahmatullah Sheikh. I have a question on the staying in same house with a brother in law who is 15 years old same small house, are there any exceptions for his stay? Thank you

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.

When a male reaches the age of fifteen, he has become an adult man (as per the Sharee‘ah), and it is incumbent on a woman to cover her body in his presence; she must not take off her Hijaab before him and must not allow him to be alone with her or to mix with her without observing the Islamic etiquette and the like. In fact, she should be more cautious around him (her brother-in-law) than around other non-Mahram men. It was narrated on the authority of ‘Uqbah ibn ‘Aamir that the Prophet, sallallaahu ‘alayhi wa sallam, said: "Beware of entering upon (marriageable) women." A man from the Ansaar asked, 'What about her (male) in-law?' The Prophet, sallallaahu ‘alayhi wa sallam, replied: 'The [male] in-law is death itself (i.e. being in seclusion with him is as serious and dangerous as death).'" [Al-Bukhaari and Muslim] The male in-law meant in the Hadeeth is the husband’s brother and his other close male relatives. An-Nawawi said: "It means that the fear of him should be more compared to others, for the evil is more expected from him and the temptations are greater in this case because he has access to the woman and can be alone with her without being censured by others, unlike other non-Mahram men…" [End of quote]

It is permissible to live with male in-laws in the same house if it is big and the facilities are not shared by all the dwellers. If the house is small or the facilities are shared, this would most likely lead to being in seclusion and the like of what leads to Fitnah. It is impermissible for her to live in the same house in that case. We would like to point out that the wife is entitled to an independent accommodation, and her husband is obliged to provide a separate accommodation for her according to his financial ability.

Allah Knows best.