To save on RAM memory, all of our Kits are set up with single-sided materials when you initially open the Kit. If this is an issue for your project, you can select the material and make it double-sided.
Here's an example from the Medieval Markets Kit in Unity:
Before: The interior of this tent isn't visible since single-sided materials are the default.
After: With double-sided materials enabled, the interior material is visible. Voila!