The RIBA wants to turn part of the bookshop at its headquarters in London's Portland Place into a new café/bar.
Planned to be up and running by September this year, the café would be open to the public during the day but would become a members' bar in the evenings.
The institute now needs to find an architect to mastermind the £60,000 project and has begun the search by launching a competition.
Martin Pascoe, the head of major projects at the RIBA, is confident the new drinking hole - already dubbed 'the Ribar' - will become very popular with both members and visitors.
'The café is a very exciting project that will have a very high profile in the building, ' he said.
'When people who are not in the know walk through the door, they don't realise there's a coffee shop upstairs. This is very much capturing a new audience.
'We have a huge footfall of non-architects coming to the lectures and the café will be in an ideal location to become a shop window to promote architecture. It's certainly not been done to make money but rather to generate culture, ' Pascoe added.
Further information about the competition, which is being sponsored by Somfy Dynamic Facade Solutions, is available from the RIBA Competitions Office in Leeds (tel 0113 234 1335). The deadline for submissions of interest is Friday 21 January.