With both Masters and undergraduate degrees in design, Linus Hultgren likes to operate "in the borderland between art, design and interior architecture," he writes. If that sounds dry, a his Instagram Toilet-House project reveals he's got a sense of humor.

Also known as the Peepoohouse, this is probably the first quasi-public bathroom that requires an Instagram account to use:

"By commenting, liking or following the peepoohouse you open the door to the toilet. You should also be aware that by this you agree that this information is publicly published on peepoohouse instagram account."

"The Peepoohouse and the owner of the peepoohouse Linus Hultgren will not sell or use this information for other purposes than promoting and improving the service and opening the door for you. If you do not agree with the terms and conditions of this Privacy Policy, you should not access, visit and/or use the Service."

Hultgren developed the project in collaboration with RISE innventia, a research institute whose work encompasses social issues, and Harvest Moon, a startup that develops regenerative sanitation technologies. All three are Swedish.