Can I Pray Sunnah Prayers Before Making up Obligatory Prayers? ( Shafi’i)

Is it permissible to pray tarawih, tahajjud, and the other sunnah prayers and then proceed to make up missed obligatory prayers? 

What are the sunnah prayers according to the Shafi’i school? 

Answer: Wa alaikum assalam wa rahmatullahi wa barakatuh,

Making up Missed Prayers

In the Shafi’i school, one must immediately make up missed obligatory prayers to the extent of one’s ability.  This means that it is not permissible for a person to spend their available time on non-obligatory prayers in its stead. 

It is permissible to perform the Witr prayer as one rak’at, although continuously doing so is disliked.