Q: Is it improper to perform the sunnat, nafl and witr waajib salaats at the back of the masjid after performing the fard salaat in jamaat in the first saff? Or is it also necessary to perform these individual salaats in the first saff as well?
A: It is totally permissible to read the sunnats and nafl rakaats at the back of the musjid. There is nothing wrong in this. It is also permissible to read these rakaats in front, in the first or second saffs. However it must be noted that after the jamaat salaah, people should move a few paces back to offer sunnats, instead of all reading their nafl salaah in that first saff.
And Allah knows best
Mufti Siraj Desai