Southlands, EOE?

If it's a free standing structure, like a small shelter or cabin it is going to be a mixture of skill and the type of building.  Everyone can learn to carve and chisel, so I'd expect if we're talking about a house made of wood, that a good portion of the materials be made using those skills.  In some instances things like walls can be constructed from those materials.  Once four walls are made, we'll close the room off (provided it's in the middle of nowhere), then after that if there's some RP done on making a roof, we'll enclose it.  Poof, you got a house, you did the work, we just realized it for you.  So that will take as long or as little time as you put into it.  We'd not need the logs, really, in this case, because you're using the skills your character has to do this.

Things like mastercrafts, we don't put limits on in regards to how many can be submitted, but we will look at your skill percent and make sure you're not drastically overestimating your abilities.  That is not to say we wouldn't put your submission in game and inform you that while you don't have the skill level to accomplish it, in time you will, and it will be available for you when you reach that level.

So to answer your question, in a long winded and round about fashion, a construction project would likely require a few rl days of work, just because of the pieces required to do it.  And if it's something the code doesn't support, we'd give an arbitrary number:  "You'll need to form up 25 long boards for me to make your raft, when you're done, send me a message."  No big deal, really.