To find the new environmental objects you have to do the following:
1. Open up the cheat console using CTRL + Shift + C on your keyboard
2. Enter the testingcheats true cheat
3. Open up Build Mode and enter the following cheats:
1. bb.showhiddenobjects
2. bb.showliveeditobjects
4. In the search bar, write up DEBUG and select any option of your choice to find the full catalog of environmental objects
Here's a video by Carl that shows how to use the new building cheat (starts at 5:05)
How CAS Story Works & Using New Building Cheats
https://www.youtube.com/watch?v=Lk-F4mFv0j8