They are the heavy metal boxes dotting properties across the country that have morphed into self-contained coffee shops or boutique food outlets.
Key points:
A second-hand container can be bought for less than $2,000 ? new one costs closer to $5,000
Rules vary for every local government area, so check with your council before buying
More than 5 million containers are moved in and out of Australia every year
Until recently they have more frequently been used as a place to store tools, paints and machinery.
In a few instances they have also been stacked together, modified and sculpted into an architecturally-designed home.
Here are some things you might want to know about shipping containers before you move in to one:
Am I allowed to live in them?
Yes. But before you rush out and spend between $1,500 and $2,200 on a used shipping container as your new home, it is worth noting that conversion is probably not as easy as you think.
For starters, every local government region in Australia has its own rules around living in a shipping container.
Most of them are similar, but you need to do your homework before you pop the box on your block.
Oxley home built out of shipping containers
PHOTO: There is plenty to love about a shipping container home, but what are the dangers and what does it cost? (ABC News: Andree Withey)
Almost all councils treat a permanent shipping container almost exactly like they would any other building on your property.
That means you will need all the proper approvals, engineering, plans, and inspections just as you would for a granny flat or similar building.
That is the same deal for the container you want as a backyard shed.
What's more, you will have to modify your container in order to live in it ? because you probably want actual doors, windows, fixtures and plumbing.
Everything you change about the container brings a risk that you're making it weaker, which means it may need reinforcing.
Dr Vidy Potdar from Curtin University in WA explored all of these options as part of a project to find out what it takes to build a container home in Perth.
"Engineers are cautious when issuing structural certificates for reused containers," he said.
"They don't know what it has experienced in the past ? maybe it was dented or hit.
"And the moment you switch from used to a new container, the price blows away ? it becomes very expensive that way."
For a new container, expect to pay at least $5,000.
A shipping container converted into a tiny home.
PHOTO: A shipping container converted into a tiny home. (ABC News: Laura Beavis)
What if I just want one for a little while?
That might be allowed, but temporary use generally means for a few months, not years.
Queensland's Sunshine Coast Council just reinforced its own rules around containers, meaning no approval is needed for 30 days' use in an urban area and up to 90 days in more rural areas.
An exception is made for construction workers using a container as storage, but once construction is completed the container has to go.
In Victoria, Cardinia Council requires a permit if you put a container on your own property, while South Gippsland Council does not allow them in any residential area.
In New South Wales, Wollondilly Council went to the Land and Environment Court in 2016 after someone refused to move an "unauthorised" container from their front yard.
In north Queensland, Mackay Regional Council has threatened people with fines over unapproved containers in a rural area.
The common theme here is that neighbours complain and councils respond, not just for aesthetic reasons but because containers are also potentially dangerous.
Is my shipping container trying to kill me?
Maybe. The issue with shipping containers is that you usually have no idea where they have been.
Used containers may not have a detailed history, so buyers do not necessarily know what potentially deadly materials have been inside for long periods of time.
For instance, a container could have been used to carry fertiliser, poisons, food or stuffed toys.
Container Terminal, Tempe
PHOTO: Second-hand shipping containers can make for a risky home or shed, because you don't know what damage it has suffered before it made it to your property. (Photographer: Stephen Burstow)
Dr Potdar said while some might be structurally perfect, others could have been dropped from a great height.
"If a container was used to carry some kind of harmful chemical or something that is unhealthy for humans, we actually cannot see it or smell it when we enter a container [but] it is there, it is hidden.
"It's a health and safety risk to enter a container which you don't know what it carried in the past."
At least it's cheap, right?
Well, not always. Dr Potdar crunched the numbers in Perth to find out how much money could be saved opting for a container home compared with a traditional stud-frame house.
"It's 6 metres by 2.5 metres, so more than 12 square metres of covered space for less than $2,500," he said.
"They think, 'if I can stack a few containers and build up a home, it would be very affordable'."
But Dr Potdar does not live in a shipping container, which provides some insight into what he found.
"I was hoping the cost of doing a shipping container would be relatively cheap, but the answer was not that interesting," he said.
"For the purpose I was investigating it for, it didn't make sense to go that route
