Hello, the ceiling of the system is generated by default. The specific operation steps for making a terrace and an uncovered balcony are as follows:

Method One (only applicable to the design version),

1. Find the space to make a terrace, click the ground to pop up the space attribute panel, and turn off the ceiling.

Method Two, Build with floor platforms and pillars

1. In the 2D mode, place the floor platform, and then in the hard decoration - components and hardware - railings, select the railings and place them on the floor platform.