I made a vow to Allah, the Exalted, that I will slaughter a calf and dedicate the reward to my dead parents if He granted me success in building three floors. Is this permissible?

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

The dear questioner has made a vow to Allaah, the Exalted, that if He grants him success in building three floors, he will slaughter a calf and dedicate its reward to his dead parents. Slaughtering a sacrificial animal is an act of obedience to Allaah, the Exalted, as He says (what means): {So pray to your Lord and sacrifice [to Him alone].} [Quran 108:2] Offering charity on behalf of the deceased is an act of obedience to Allaah, the Exalted, as well. Abu Hurayrah reported the following:

"A man came to the Prophet, sallallaahu ‘alayhi wa sallam, and said, "My father died and left behind wealth without making a will regarding it. Will he be relieved of the burden of his sins if I give charity on his behalf?" The Prophet, sallallaahu ‘alayhi wa sallam, said: "Yes."  [Ahmad and Muslim]

According to most scholars, it is incumbent on the person to deliver on this kind of vow. ‘A’ishah narrated that the Prophet, sallallaahu ‘alayhi wa sallam, said: "Whoever vowed to do an act of obedience to Allaah, the Exalted, must do it." [Al-Bukhari and Muslim]

Allaah Knows best.