The advertisement shows photos of the compact apartment including a spartanly-furnished bedroom with the three-tier bunk bed and covered mattresses.
It says there are already eight flatmates from around the globe in the flat including men from Colombia, India, China, Sri Lanka, Brazil, Thailand and Indonesia. They were described as "quiet and clean".
It says the bed would best go to an international male visitor on a student or work visa.
The advertisement says the Vincent St apartment, which is located in the heart of the central business district, has five bedrooms and two bathrooms.
The advertisement has drawn a range of views on social media.
One person wrote on Reddit: "It's not really what we mean by 'build up'. If people need shelter then I don't see this as being a terrible thing in a city that has completely failed on housing policy. Don't punish the desperate."
Another wrote: "Anywhere renting this should at least face some slightly enhanced health and safety regulations."But some took a more light-hearted view.
"The top bunk has great views of the bedroom."Added another: "No night owls lol."
The person who listed the advertisement has not yet responded to messages seeking comment.