when will the next era come

I am at seaport level 435.
I've been in the concrete era since level 300
when does a new era come and the disign of the houses changes ?

pixel_player81600470 House design is by building level IIRC?

I'm level 597 mine looks like this:

If yours does too you are at the highest style level.

Concrete is currently the highest available crating material for buildings

I think buildings are looking like that starting from about lvl 240. I'm at 276 and it has been a while since that.