This treehouse was a fun project! I play Minecraft on a server with some friends, and we reset it whenever a big update comes out. I built this during 'Season 2' of the server, and I'm pretty proud of it.
I wanted a treehouse built as 'closely to the tree' as possible, Trying to make it appear that the rooms were a part of it, inseparable, rather than being a bunch of wooden planks hanging in the air. So my main concern starting out was developing a set of materials that could look natural and 'seamless' within the context of the larger trees. This ended up including jungle logs, planks, leaves, stripped logs, fences, and vines. I didn't expect to be able to make a visually interesting treehouse from just the jungle wood materials, and spent a lot of time thinking and less doing than I would've liked, but I managed to develop a kind of 'design language' I was happy with. Using the original canopy as a base, I used logs as supports and manually-placed leaves for the roof (supported underneath by stripped logs - visible further on).
Getting the tesselation right was a minor challenge. Trying to emulate Minecraft's world generation is always interesting work, trying to get all the little details right that might make things look as if you had never touched something.
Getting a bunch of double-wide chests to fit into a roughly circular footprint wasn't the easiest thing in the world. Between the space they take up and the shape mismatch, it took some tetris-ing to fit them all in there. When I reached this point though, it was clear that I would have more than enough space for almost 60 chests, stacked 3-high. More than enough for anyone's storage needs. I also experimented here with a new floor design. I used it in one other room besides the storage room, but never ended up going back and changing previous ones. I think it looks good.