I’m going to tell you a Second Life secret: there are ways to fly as high into the air as you wish. This allows you to fly over (but not down into) land on which you have no access or from which you have been banned. You can build a house 600m up in the air if you wish. If you are teleported to a store or casino or club way up in the air, you can fly away from there without crashing to the ground.
I don’t suppose this is actually a secret, but you would have to read some directions somewhere to know it. Most newbies do not, so you see them try to fly up and then they stop rising. In fact, they might even start sinking once they get above a certain altitude.
There are a number of attachments or HUDs (heads up displays) that overcome this problem. There is a free one floating around called the “flight feather.” What I recommend you do instead is get the MystiTool HUD from the store at Blumfield 26,147,296. There is a version for sale for a few hundred Lindens, but I recommend you grab the freebie version which is near the door on the right as you walk in. If you like, see if the higher priced version has the extra features you want or need. For example, it makes it easy to build a platform up in the air from which you might start constructing a house or a “sky box.”
Once you can fly up in the air, there is some basic etiquette you need to observe. If you are blocked from entering land at ground level, the owners probably don’t want you to visit their house even if it is hundreds of meters up in the air. There are several security products that may eject you from the land or even teleport you home if you trespass for more than 10 or 15 seconds.
I moved my buildings up about 400 meters and, though I have had a few unexpected visitors, I have had no problems. I think the funniest thing was when I went inworld and found one of my next door neighbors kicking a beach ball around the backyard. I left him alone to have fun.
I installed a script I modified so that I can tell when new people come onto my land and issue a one time message recommending that they respect my private property, though they are welcome to look around. Should there start to be abuses, I won’t hesitate to get one of the more heavy duty scripts, but I suspect I won’t need one.