Some businesses are seeing more people invest in fire bunkers. Others are dumbfounded as to why there aren't more people snapping them up.

• In Australia, bushfire bunkers have become a new norm.
• In America, however, businesses are seeing a mixed bag in terms of interest in fire bunkers.

For homeowners with extra cash to spare, installing fire bunkers is how they're preparing for a fire emergency.

The Guardian recently reported that in Australia "bushfire bunkers" are becoming an all too common reality. These underground steel boxes would provide a retreat for when fire or deadly smoke reaches a house and escape is impossible.

They have limited oxygen capacity — around 1-3 hours worth of oxygen, depending on how many people are in the bunker — and are meant to be temporary solutions for if a blaze crosses your path.

The underground bunkers can be made of steel or precast concrete and can withstand fire, reflect radiant heat, and keep smoke out. Additionally, the bunker's interior will not get hotter than 113 degrees.

In the US, people are also looking at the apocalyptic-looking shelters to keep them safe in case of emergency — although some business owners say that the bunkers aren't as popular here as they should be.

Janet Rosenthal, who founded Natural Disaster Survival Products with co-founder Tom Tanno in 2018, told Insider that she's seen growing interest in fire bunkers.

"People are becoming more aware about the fact that they can't trust any emergency alarm system," Rosenthal said.

Rosenthal founded her fire survival company after the Woolsey Fire devastated the city of Malibu in Los Angeles County, and her kids began to worry about what would happen if a fire reached their own home.

She began researching Australian ground safety bunkers (the state of Victoria has a formal accreditation process for bunkers). Since starting her business, she's found more and more people are looking to invest in these fortresses — especially after this year's Maui fire, which ripped through the island at 60 miles an hour.

"The word gets out," Rosenthal said. "I will just tell you, as an aside, I got a lot of interest after the Maui fire, which nobody would have anticipated."

Ron Hubbard of Atlas Survival Shelters told Insider that he's seen the opposite. Hubbard, who specializes in bomb shelters, said he began selling fire shelters following the Camp Fire, which destroyed the city of Paradise, California.

Hubbard said that he's lucky if he gets a few calls a year for a fire shelter.

"I just don't know why they never caught on," Hubbard told Insider. "But you would think with as many fires as we have every single year in California, more people would be concerned to buy a product that would give them some safety."

Hubbard, who sells bunkers all over the world, has theories as to why they're more popular in Australia. One reason could be that bushfires travel faster than forest fires. Another could be that Americans just have more opportunities to vacate, and may not feel the need to have a second option. Hubbard said the sales he gets are from people who live in remote areas and are afraid they may get trapped by a fire.

But he says he still doesn't understand why it hasn't caught on more.

"More people die from wildfires here in America than die from tornadoes, yet the market for tornado shelters — they sell about 50,000 a year. It's a disproportionate scale," Hubbard said.

Perhaps one barrier is the price tag.

Personal fire bunkers are meant to be installed in backyards near homes. And to install one, you need to have the means to do so.

Rosenthal pointed out that you need to have enough land to install a bunker. People with small yards are probably out of luck, although she said her business provides other products for people who still want to stay safe during a fire.

The bunkers aren't cheap, either.

Rosenthal said that her bunkers, which are pre-made, can go for "a couple thousand." A more difficult installation will drive the price up.

Hubbard told Insider he sells fire shelters that cost $15,000.

This means fire shelters are probably not accessible to low-income communities. In the US, research has found that frequent wildfires tend to hit low-income communities harder and more frequently.

Regardless, people continue to buy these shelters. Rosenthal said she expects to sell more fire bunkers as climate-induced wildfires become more common in the US.

"We've had a tremendous amount of rain in California specifically," Rosenthal said. "And when we have a lot of vegetation growth with the rain, and when the wind-driven heat comes, that's when everything becomes so much more deadly."