Thanks! Lots of scaffolding was used (built with bamboo and spider’s web). Dirt can also be used. Ladders, too.
The trick is to make water pools to jump down into once you have exhausted your inventory and need to refill its stone.
Towering architecture as such in pure survival mode is not hard: Just build tall, climb a lot and jump into water. The hard part is getting a sense of proportions and spotting counting errors when they occur.
It was built in survival (with plenty of fall deaths), but I frequently switched to spectator mode/creative in order to fly around, control measurements and get a good look on progress, thereby catching errors early on and getting a sense of proportions.
The overall shape of the big temple was made by doing the series of domes in a staircase formation (like a ziggurat), using repeating simple mathemathics once you’ve settled on the first dome. It was only blind luck that the temple’s side walls happened to align with the flank domes’ outer edges, bar two stacks of stone on each side that needed to be moved. Then the rest of the temple’s top shape was determined by the levels set by the staircase of domes, with constant reference to Byzantine architecture.
Mobs were killing me time and again while building this, and they do spawn on the roofs where no torches have been set out.
My friend Johan von Elak and I agreed a year ago to turn off mobs damaging blocks on the server (there is such an option): As such, exploding creepers kill as they always do, but they do not damage your build, and Endermen no longer randomly place around dirt blocks that need to be cleaned up.
The game becomes a lot more enjoyable once you turn off mobs destroying blocks, and allow yourself to fly to get a better grip of how your build progresses. The build still happens in survival, but you need the bird’s freedom of movement to check and spot faults early on.
But it can be done without any flying whatsoever. More errors will occur, and the proportions will be less good, but big builds are just as doable without any flying for perspective.
Domes require no flying. Once you figure out the way to turn a Minecraft circle chart into a sphere (cross vertical and horizontal circles, then align corners as best you can) and nails the first dome after trial and error, just take a reference screenshot and build the other domes after it, counting and checking all the time.