I would love to see some more "elaborate" base building materials. I know there will be more building materials added in future updates but...I am an Interior Designer who spends too much time building bases in a video game as a shrunken kid  💁‍♀️

I think bug wings would make for some really cool features like skylights or "glass" ceilings and stained glass windows...Mosquito or lady bug wings or adding dragonflies. If the fall update features a greenhouse it would be awesome to see some building materials to make glass house type structures. 

More railing options would be nice-half width railings and angled half width railing.

Also a quarter rounded pieces to fill in some of the round base building pieces as well as quarter triangle flat piece's, half pillars...

and chandeliers, hanging ceiling lights ect....lets goooo

 

I like all the suggestions, particularly the stained glass as we can mess around with the lighting features near the windows. 

id be cool to see them use snail shells as abuilding material as well, maybe roofing of some kind. i guess like slate roofing tiles maybe