What if the residential property does not allow the balcony to be sealed?

It is said that the balcony is the owner's freedom and the property has no right to interfere. But if you sign a contract with the property, it will have legal effect. In many places in Beijing, owners can stamp, but it is more reasonable to follow the unified style and color of property regulations. You can negotiate with the property. The main consideration for performance is the consistency of appearance. If the style is unified, it should be possible.