Ok, so I messed around a bit looking at console commands, even took a memory editor to try to find any additional commands that could help me modify terrain while in game. No luck....

I tried changing the scale of some boulders, but when you change the scale, you end up just walking through them as if there still the same size.

I know you can change terrain in the creation kit, but has anyone figured out a way to change terrain in game?

As far as building a house, or any building for that matter, I know there are mods for the fallout games were this is possible. I haven't found anything for skyrim yet. Im sure it's possible to load a building into the game, what are the limitations to this? Can I load a large stone, and make a building one stone at a time? Would this be memory intensive?

1. When scaling object, if the collision doesn't take, just duplicate the object then delete the old one.

2. Changing landscape in game is not possible as afar as i know.

3. Yes, it is possible, but vastly inefficient. The work to make such a thing is probably not worth the time.

Dig a hole, build a house

Whack a mole, hit that mouse!

I don't think it's ever been possible to edit terrain ingame. And unless an object is animated, changing it's position or scale does not change it's collision as well. (That's why you walk through the giant boulders)

You can still make a mod where you build a house/etc on the premade terrain. Look at RTS for Fallout 3. (And I think NV too) It let you build your own village. Gather wood, stone, and food. It was pretty shabby but a great concept, and loads of fun to mess around with.

One way to make an house building mod would be to drop an marker object, say it represent the position of the front door, then activate it to convert it to an frame so you can see how the house will stand.
Frame act as an container and then all materials are present you got an house, you could probably have building stages, if you made multiple frames.

Sounds like someone is trying to mod Skyrim in to Minecraft

(Hint: not really possible, sorry)

Or Maybe Dig Dug.

Yes, This is seems to be pretty much how the RTS mod for New Vegas works.

I see some possible issues with building on unlevel terrain, trying to get the house to fit just right. Most buildings will also need some sort of stairway. Another thing is most houses are instanced so that when you walk through the front door, you leave skyrim instance and enter that one houses instance. So you may have to stick with uninstanced shack models like in the New Vegas RTS mod.

We all know about the open cities mod that removes instancing in major cities, but what about removing instancing of individual buildings? Would that take up to much system resource? It would be nice to having actual working windows.

that's one reason I've been trying to get child worldspaces to work. If you can get your house to load into a worldspace that inherits the terrain, etc, of the parent world, you COULD have working windows...but nobody will tell me how to get a worldspace to inherit the terrain of the parent space. My last attempt was definitely NOT working...the supposedly imported terrain, which SHOULD have been of the shoreline near Northwatch, was a set of rolling hills with no water.

Skyrim into Minecraft is possible, but Minecraft into Skyrim, not really.