Fatwa ID: 02421
Answered by: Maulana Maruf Ahmed
Assalam u allaikum, My question is that if a person is offering obligatory prayers on his OWN at home, can you join him to make it a congregation. So that he becomes the imam and you follow him.
JazakAllahkhair. Mohammad Farhan
بسم الله الرحمن الرحيم
Although it is more virtuous and rewarding to perform congregational prayers in the masjid, congregational salah is valid if prayed at home. The preferred opinion of the Hanafi Madh’hab is that the Sunnah of congregation is fulfilled even if done at home by, for example, a man leading his wife in prayer. 
And only Allah knows best.
Written by Maulana Maruf Ahmed
Checked and approved by Mufti Mohammed Tosir Miah
Darul Ifta Birmingham