بسم الله الرحمن الرحيم
If the direction of your mosque is according to the old mosques of your locality then there is no need of any change. As the appliances used to fix the Qiblah direction such as observatory, astronomy, geometry and other things are just evaluative and sometimes the experts have drastic variation in their rules and regulations. Moreover, as per them the Qiblah direction of the Masjid Nabawi is not completely accurate rather it is towards south in 10 degree, whereas Maqrezi has written in Kitab Al-Khatat (2:256) that when Emir of Egypt Ahmad Tulun intended to build his Jama Masjid he sent some experts to Madinah to check the direction of Masjid Nabawi by observatory instruments they found it 10 degree towards south in contrary to the direction observed by astronomy. (Jawahir Al-Fiqh 2:382-383 published by Maktaba Darul Uloom Karachi). Yet, the direction of Masjid Nabawi is quite accurate as per the Ummah as it was fixed by revelation and inspiration of the holy Prophet (صلى الله عليه وسلم). Almighty Allah presented Ka’ba in front of the holy Prophet Muhammad (صلى الله عليه وسلم) as miracle. And the holy Prophet Muhammad (صلى الله عليه وسلم) established the Qiblah direction of Masjid Nabawi. (Jawahir al-Fiqh 2:382 with the reference of Al-bahr al-Raiq and Rud al-Muhtar)
And if the direction of the mosque is slightly diverted from the other old mosques i.e. less than 45 degree then too salah shall be valid in the same mosque and there is no need to change the old direction. (For detail see Fatwa Khairiya 1:6-10 & Jawahir al-Fiqh 2:325-421).
Allah knows Best!
Darul Uloom Deoband