Are you the kind of person who'd like to live as low-impact as physically possible? Or maybe you have a teen-aged child that you'd like as far away from your house as possible due to their loud and annoying music? Do you have a very large tree on your property? If so, maybe "mad engineering" industries' tree-house program is for you!
You will need:
* A huge tree
* 100 pounds of planks
* 10 boxes of nails
* Two or so windows
* Ladder (can make it out of more planks)
* Electrical wires
* Electric outlets
Install the ladder into the tree.
High up, but below the top of the tree, construct a frame of planks. This is the floor. Try to use existing branches for support, and install support beams where plausible. (As many as you can, because it would suck if the floor gave way.)
Attach the pipe to the tree. (Possibly near the ladder, but definitely in a way that one doesn't trip over it.)
Lay plywood over the floor, but don't attach it yet. We may need to lay something under.
Thread electrical and phone wire through the pipe. They can be attached to an existing installation.
Install framed walls to the edge of the floor. Where you want the windows to be, have a short beam up to a horizontal one.
Attach plywood to the outside of the walls. This may require a crane, or a second ladder.
Install interior electrical. Thread up from the pipe, drill small holes in the wall frame, and thread through. Nail boxes and outlets to the frame, according to code.
Install insulation, hiding the exposed electrical work.
Attach plywood floor. Cover with hardwood, or carpet.
Frame in a ceiling, then a roof on that. (Keep the rain out.) Cover the roof with plywood, and then something waterproof. (Probably actual roofing shingles.)
Move in a small amount of furniture. Probably a chair, or a bed, a desk, and maybe a TV.
What happens next depends on what the tree-house was built for. If it's a "low ecological impact" dwelling, then you should build a garage nearby for any vehicles you own, and put solar panels on that to provide the power. (And if you're remote, batteries for night.) If this is a teenager's pad, and your house is two stories, maybe an external door and a bridge to your house, so they can come to dinner.
In any case, it's one of many strange dwellings that I can semi-describe how to build.