I'm in the middle of making a castle. After 2 days, I managed to finish the main hall, save for the gold "G" above the fireplace. To make the entrance hall alone, it was necessary to create a quarry, as well as a slate foundry. A 10x4 wall of forges lets me mass produce slate rock for the walls of the castle, since I don't like the look of cobblestone walls on cobblestone floors. To fuel all of these forges, I basically had to take somewhere around 5 stacks of iron to make buckets, dig a shaft down to a lava well, and use the lava buckets to fuel the forges.
This is all going on while I'm shuttling inventory loads of stone, wood and dirt (to expand the island I'm building on) over about 3 or 4 view distances to the castle foundation's location, which is across an ocean on an island just off the closest western mainland.
One room down, tons to go. Building a castle in Survival Mode is fairly difficult.