Birnir is an Icelandic artist working with text, film and theatre as an author and performer. His works often revolve around environmental matters and the person in the context of the commercial and attention economy. Birnir does individual works as well as being member of devised theatre groups CGFC and Ást og Karóki. He is the official playwright for Borgarleikhúsið city theatre the year 2022-2023. He has hosted and co-hosted various events, including experimental theatre nights in tóma rýmið, experimental theatre festival Safe fest and Gullmolinn short film festival. He is the founder of tóma rýmið experimental theatre space in Reykjavík, Iceland.