What should be done regarding mosques where an error in the qibla direction has been detected?

Facing the qibla (istikbâl-i qibla) is one of the obligatory acts of prayer. Those who are near the Kaaba and can see it must face it directly while praying. According to the majority of Islamic scholars, for those who are far from the Kaaba, it is sufficient to face the “direction” of the Kaaba. The essential point here is that the person praying should not be completely deviated from the “direction” in which the Kaaba is located. Accordingly, minor deviations do not affect the validity of the prayer. (Ibn Rajab al-Hanbali, Fath al-Bari, 3/66-68; Mardawi, al-Insaf, 2/9; Ibn Abidin, Radd al-Muhtar, 1/430) As long as the Kaaba or its vertical alignment towards the sky remains within the angle of the person’s face, the person praying is not considered to have deviated from the qibla. (Ibn Abidin, Radd al-Muhtar, 1/430) Therefore, as long as the person praying does not turn 45 degrees or more to the right or left from the straight line connecting them perpendicularly to the Kaaba, they are not considered to have completely deviated from the qibla direction, and this does not affect the validity of their prayer.

When a Muslim prays in a mosque, there is no need to investigate the qibla direction separately, as mosques are constructed after determining the qibla. However, the following principles should be considered in practices related to mosques:

a) Since the qibla direction can now be determined precisely, newly built or reconstructed mosques should be oriented so that their direction/mihrab is exactly aligned with the direction of the Kaaba.

b) For mosques built in the past that are later found not to be precisely aligned with the Kaaba, prayers previously performed in them are valid. This is because the qibla of these mosques was accepted as correct according to the conditions of the time they were built, and prayers were performed with this understanding. However, if experts determine that the deviation exceeds the permissible limit (45 degrees or more), this should be corrected as soon as possible and in the most appropriate way. After it is established that the deviation is 45 degrees or more, prayers knowingly performed in that direction are not valid.

c) According to the determination made by experts appointed by the authorities, if the degree of deviation in the qibla of a mosque is within the permissible limit (less than 45 degrees), prayers performed in such mosques are valid. However, to eliminate potential disputes among the congregation, the interior of the mosque should be rearranged to correct or minimize the angle difference as much as possible within available means.

Source: T.C. Diyanet İşleri Başkanlığı, Din İşleri Yüksek Kurulu