I'm not actually sure what use the Lean-to serves, other than looking pretty, so I'm suggesting an alteration to it. First, I was thinking it would be nice if there was a second version which you could attach to walls. Would looks something like

Though I guess it doesn't really matter.
The purpose it would serve is that you can put things like boats, cauldrons, and other 1x1, 2x1 space items under it... and it would give it the same degeneration bonus as if it was in a cart, or indoors... that way people could just leave cauldrons and such outdoors, instead of having to take it out and put it back when finished. If the Lean-to already does this, then ignore my suggestion.
Sheds (outdoor storage)
We don't really have any suitable outdoor storage in my opinion for players with no metal. Cupboards and crates degrade too fast, no one wants to litter their yard with tons of baskets and pots, coffers are a bit better but still too small, and the other things require metal.
It would be nice if we had an outdoor storage that:
was large (like, 10x10 or bigger)
didn't degrade too fast
doesn't require metal
I don't think it should be by any means easy to make, but just for those without metal can have large outdoor storage too. Maybe something like:
2x rope
5x birchback
3x leather
10x straw (for the flooring, you know

1x bone glue
15x board
10x block of wood
2x raw glass (for the pretty little windows, you know

Though I guess that is a lot of "ingredients". It's just nice to have all your outdoor stuff in one area, instead of having to go through 20 baskets looking for what you need.
Let me know what you think.