The sandbox environments are one of my pet peeves in regards to the game currently. At this moment the environments isolate one's builds from the world to a certain degree; The suburban plots have no driveway, the island is perfectly rectangular.
What i propose to be added to the game is a way to modify, or fine-tune, the plots in a way so the player can blend their build in with its surroundings more proficiently. I think this potentially has two aspects:
1 The ability to change the surroundings through options. These could be toggles for various aspects of the environment surrounding the sandbox plot. Some of these ideas are more major than others and would potentially be required to set before a plot is loaded, others are potentially aspects that can be changed on the fly. Some examples would be:
(minor)
The ability to turn on and off the fence(s) around a plot.
The ability to pick between various island forms. (square islands are a little weird)
Decide what clutter is present around the plot. Like hiding the outhouse in the forest.
(major)
Decide the general landscape (hillside, top of a hill, crater, orientation) of a plot.
Decide what types of buildings are around.
Decide on what types of, and how, paths or roads connect to the plot.
2 The ability to build beyond the "border" of the plot. Extend the editable area beyond the actual plot, so the player can construct their own driveway between the sidewalk and the road for example. Seen the intention of a sandbox mode is to freely, without limits, create what the player desires within the capabilities of the game('s engine) it wouldn't be story-breaking to edit the surroundings. Rather, this way the artist will be able to properly blend in the property within the surroundings.