Upon purchasing a property in an urbanization the new owner also becomes the owner of a fraction of the common areas of the complex. The common areas are split into hundredths and each owner has a specific number allotted to them typically according to the size of the property that they own in the complex.
Of course with ownership comes responsibility and there is an annual fee to be paid in order to maintain all of the common areas and amenities. The fee paid by each owner corresponds to the number of shares in the complex that they have been allotted. The number of shares that have been allotted to each property can be discovered by checking the title deeds of the property.