1) Why can't I upgrade the building?
- Not enough resources.
- Not enough crystals on the account.
- Another building is already under construction. (To be able to build two buildings at the same time, you need to hire a second Builder in the City Center building. There is a maximum of 2 Builders available).

2) How to improve the building?
- Click on the selected building and in the window that opens, in the Improvement section, click on the “Improve” button.

3) Can I build 2 buildings at the same time for resources?
- Yes. For this you need 2 builders. Initially, there is one builder in the city, and only one building can be built in the game.

4) Why do we need builders?
- Builders are required in order to build and improve buildings in the city. If you have 2 builders at your disposal, and not one, you can build two buildings at the same time.

5) How many builders can you hire?
- The maximum number of builders in the city is 2. One builder is present in the city initially. Accordingly, you can hire another builder.

6) Is it possible to hire a builder without spending crystals?
- When hiring a builder, only crystals are spent.