So i was wondering and stuff but ya know me and all i wonder a lot. How big do other Pixel Artists' make their Buildings/Trees and other big objects. This has always been a problem or argument for me and others because its like Why is the Building's door as big as it or Why is the character as big as the Tree!! and stuff so just wondering .. Any thoughts?
To avoid the problem of bad proportions when I'm working on a blank canvas I take the player mob and paste it in the bottom right corner. Then I can always quickly look over to see if what i'm making is proportional to the character, and consistent to the style.
I think it could be one of two things, firstly, in old game development you'd have limited resources, so you'd have a small tile for a tree (or maybe 2x2), and a player would be one tile. It's possible that pixel artists just kept on to old traditions. And... while writing this I forgot what the other possibility might've been, so I'll just say it's ^^that^^ one.
i usually start with my base at the bottom right aswell and stack the base(copy and paste) to get the proportions sizes perfect.

Base wide
Base height

Since my favorite number is 7 i tend to make my buildings, trees and everything 7bases tall or 7bases wide.
Pixel artists can make their buildings and trees as big as they want. You don't have to even go with proportions to the base. But because Byond is 1:1 for pixels you shouldn't try to take up a large area with a building because people really wont be able to see it.

Just make sure that buildings have a middle tile (that means the number of tiles horizontally are odd numbered. 1,3,5,7,9,11,etc) that way you can make a doorway. Unless you want double doors, but those would be pretty big doors if we're talking 32x32