Clan islands
Clan islands are a general tile for a group of islands that are in effect owned by families.
It often starts with a member of the family moving out, others visiting and then they spot the opportunity to have a whole island of their own.
They vary enormously in size, some are occupied just by the family while others are owned by the family but have some either let homes or holiday accommodation that is let.
The most popular style has a large house comprising shared space and around this a collection of properties in which the families live. Often this is spread out within common grounds and often enclosed within a wall around the island. On the first floor below ground are more facilities so as to keep the surface clear, and at water level are boat docks often coming off a shared entrance to the outside.
The inside or lower floors of these islands are sometimes used for a family business, sometimes made up of let accommodation and sometimes just let out as shell space where different uses are developed. The use is varied, the common feature normally being that the first floor below ground and surface is exclusively reserved for the family and not accessible from the remainder if the island.
While most people think of the island being developed by a family, it is just as likely to be by another developer who has a use for the inside or lower floors and wishes to add the income from a clan island to the project. For example shopping centers, training facilities, factories and many others don't require the use of the island surface, while they may not want to provide as many facilities or the weight of a larger housing complex. In these cases usually items like pools are left out, as these take a lot of supporting on higher floors.
It can of course work just as well the other way and the family decide that housing or other items added to the lower floors can be used to pay the largest part of the cost of building their own island.
Like all developments within the floating kingdom. It has to be remembered that all developments are in pairs, one for the developer and one given to the kingdom, which is let out producing revenue so that taxation is not necessary. From this you can see that at least half the family islands are let, rather than owned by families.
People new to this concept do not sometimes realize as everyone is doing the same you are on a level playing field and as ocean space is not limited there is no land cost as there is when building on land, so the eventual costs are lower when building within the ocean to on land even allowing for one for the kingdom. Developers also of course realize that with no tax, their profits are theirs not largely the governments.