Morten Longum has an architectural masters degree from NTNU in Trondheim from 1997.
After working in a company doing residential development he started architectural company TAG arkitekter in 2009. TAG arkitekter is from 2023 part of Sweco Architects.
He has since 2015 been part of developing future plans for transforming the industrial place Pusnes, into a new town on Tromøya, Arendal.
He is based in Oslo, working as a business unit manager in Sweco Architects.