Does anyone know when Season 5 starts filming?

Just a random question since I'm only got into OMITB in the summer, does anyone know when season 5 is meant to start filming? Albeit, do realise it could be delayed what with the horrific events in LA currently, & the potential Martin's house may have burnt down considering he lived in the Pacific Palisades. (I only know this from reading his autobiography; which btw, is definitely a good read if you haven't read it... ) & the other property he had brought recently apparently in Mandeville Canyon which from the news ive seen was apparently on fire yesterday.