There have been a bunch of daring propositions to counter San Francisco's — and other cities' — housing demand: underground bunk beds are one of the most recent that come to mind.

But Bumblebee Spaces is drawing inspiration from its namesake insect's penchant for space optimization and has designed systems that store furniture in the ceiling, which has traditionally been unused dead space.

The San Francisco-based startup builds modular ceiling systems to "unlock" living space and double or triple the utility in high-density, high-dollar-per-square-foot regions, "where space is a premium."

The idea is that the systems can, for example, take a two-bedroom apartment and add a third room with the modules, one of which could be a privacy wall, cofounder Sankarshan Murthy told Business Insider. It could be three roommates that share the space or a couple, a family, or just one person.

"You can add and remove modules as the life changes inside," Murthy said.

Think of the startup as a furniture, storage, or — as Murthy called it — an "inner space" company. Solutions to storage problems continue to resonate with the market, Murthy said, from storage in the cloud to, now, storage in the ceilings.

Founded in 2017 by Garrett Rayner, Prahlad Athreya, and Murthy — a veteran of Apple and Tesla who worked on the Apple Watch and Model Y electric car — the company has raised $22 million in venture capital from firms like NTT, Ashton Kutcher's Sound Ventures, and Valor Equity Partners, led by one of the first independent board members of Tesla.

The company recently gained some public attention after a now-deleted Craigslist ad went viral showing a $3,295-a-month studio apartment outfitted with its systems, with a bed that lowers from the ceiling, as SF Gate reported. Out-of-the-box contraptions that could help solve the city's housing crisis regularly generate buzz.

Bumblebee Spaces will sometimes work with homeowners to retrofit their homes, but the company mostly sells directly to multi-family developers that either own, operate, or develop apartments themselves. The startup focuses on retrofitting, but it's also working with some developers to architect the space around the ceiling systems, which could be cheaper overall.

"Why would you add a traditional closet when you can add Bumblebee wardrobes whenever you need?" Murthy said.

The startup has projects outside of the Bay Area, like in New York City, and four ongoing or planned projects with developers in San Francisco. The city could benefit from such a concept — housing is tight and there's not enough of it to meet demand.

To Murthy, there's something potentially wasteful about constantly building in two dimensions to meet housing needs. For people wanting a guest room to host family when they visit, to have a play area for their kids, or a space to entertain, it's only utilized occasionally.

"You don't need a room for that," he said. "You just bring down the room when you need it."

Here's how the Bumblebee Spaces systems work.

Artificial intelligence also works to learn from your behavior and be able to interpret your needs, such as remembering where you put what.

"Our AI learns from your preferences and routine, then adapts to suit your life," reads the company website.

But another source of inspiration is how a show is run on a theatre stage, with the fly systems lifting set designs up and down as the performance goes on.

Bumblebee Spaces was his "detox project," or side project, that he worked on during weekends and nights during his 18 months spent at Tesla.

The modules are categorized as fixtures, furniture, and equipment (FF&E,) a term used to describe movable furniture that is not permanently connected to a structure. They're similar to light fixture installations in a home.

The company starts by installing railings of a sort onto the ceilings.

"Then we hang the robots off of those, and all the load is kind of distributed all over the ceiling," Murthy said.

The modules and their sensors are intelligent, said Murthy, and possess an awareness of the environment and interaction with the user. The systems have "layers" of safety, according to Murthy. A series of sensors, which are similar to the kind used in garage doors, help make the machines aware of their surroundings.

There's a limit on how much a module can lift and what load you can put on it, meaning if someone was laying on the bed, the system is designed to remain in place even if a user instructs it to recede into the ceiling.

The sensors also scan the space underneath where a module would descend into and, if someone or something was in the way, would remain in its lofted position.

According to Murthy, it's a difficult feat to accomplish, but he said it's something that the company has done.

Bumblebee's systems would probably fall into the smart home classification, which Murthy said has been "hijacked by light and speakers" in recent times. He said what his company is designing may be a better example of what a smart home could be.

He did say that since the systems are defined as FF&E, it doesn't cost as much as traditional home add-ons.

The company does need to consider codes regarding the mechanical, electrical, and plumbing systems.

It also has to consider how much load each anchor can take, how far away the modules must be from fire sprinklers, and what kind of electrical wiring can be run, which Murthy said involves a low voltage.

"On the electrical side, we are just like an appliance," Murthy said.

The two-bedroom apartments at The Landing transform into three-bedrooms thanks to Bumblebee's systems, Murthy said. Two-bedroom units listed available on the website are priced between $4,760 and $5,000.

Bumblebee Spaces currently has 24 employees, Murthy said, that came from big names in the tech world. But the company prides itself on its self-described scrappy roots, Murthy said.

Its last funding round was a Series A in November 2019 that raised $18 million.