There are all kinds of engineering ~ electrical, mechanical, aeronautical, biomedical, architectural ~ and they all incorporate design as part of their process. Being a child at heart, I've never lost my fascination with whimsical or lateral-thinking ideas which lie wa-a-a-ay outside the box of conventional vision. Following are several designs I've come across, just in the past few days.
Treehouses have long been the normal home design in many forest cultures, and now are sought after as a green alternative to living in a box. Here is a link to 10 Amazing Tree houses ~ Plans, Pictures, Designs, and Building Ideas. "Some structures are built on trees or hung from trees, [and some] are even grown from trees or even built right into a tree." Note that descriptions follow each set of photos.
I love the designs which are most organic, which blend into the environment and whose rooms resemble natural shapes. So it may seem surprising that of these ten, my favorite is number ten, the Syberite tree house, which looks rather futuristic and non-endemic (see image above, click to enlarge). Yet I think the use of natural colors and incorporating native growth onto the structure and supports would allow it to blend into the environment. "The Syberite tree house project blends modular design with low-impact living. Layouts are allowed to conform to the natural landscapes around them to take maximum advantage of views and natural light without disturbing the local environment. The thin foundational supports are designed to minimize impact on root systems and the ground surface. Rainwater collection, solar panels, wind collection and other sustainable systems are also integrated, making the house mostly energy independent." Cool. One could even imagine adding a small enclosed observatory for star-gazing in all seasons.
Taking your house with you when you travel has been a challenge for automotive engineers for generations. The Piaggio APE 50 Camper offers a modest solution. This three-wheeled design has been around in mini-truck and taxi form for years. The camper evolution is small, a bit boxy-looking, space-efficient in the manner of submarines and spacecraft, and intended for one person (with perhaps a cat). If you're a person of simple needs and an open-ended schedule, this could be a fun vehicle.
Even more appealing to my eye is the NAU Ecco Camper. I love the aerodynamic design, and its dramatic transformation into an unexpectedly spacious living area. In travel mode, it is only 4.5 meters long, 2.5 meters wide, and 2 meters high. Power comes from roof-mounted solar panels, as well as from any 240 volt electrical outlet. In living mode, the roof unfolds upward from the forward end like a flamenco dancer's fan, expanding the interior into a space suited for two or more occupants. Check out the link for some eye-popping images.