Lahoud, who has already been appointed head of the RCA's architecture programme, will take up the position of dean of the School of Architecture in January 2016.
He will be charged with developing new programmes for the London school, which has plans to create courses in landscape design and city design.
"It's a fascinating moment to be at the RCA, there are some very serious ambitions taking shape in the college, I am looking forward to help guide them," said Lahoud. "The coming years promise to be enormously exciting."
Lahoud took over the positions of both dean and head of architecture from Alex de Rijke, who resigned after four years at the school. Lahoud was initially drafted in as a replacement head of architecture in September 2015 but has now been promoted to fill the two roles.
The school's head of research Susannah Hagan had been acting dean in the interim between De Rijke's departure and Lahoud's appointment.
"Adrian impressed the search committee with his clear vision for architecture as a school," said Naren Barfield, the school's deputy rector.
"In his short time at the college, Adrian has impressed us all and I'm delighted that he has agreed to serve as dean during an exciting period of growth and academic innovation, including designing and launching new programmes over the coming years."
De Rijke's resignation was one in a series of recent changes in the RCA's senior management, including changes in roles for course leaders Ab Rogers, Clare Johnston and Jeremy Myerson.
"There's quite a few people leaving the RCA but I think we are leaving for slightly different reasons," Myerson told Dezeen in March this year. "It's a generational thing. There's a changing of the guard at the RCA and that's no bad thing."
This year also saw the departure of Anthony Dunne and Fiona Raby and the suspension of college's Design Interactions course.