Usually there are restrictions on how close you can construct to your neighbor and to the back of the property, or on the size of the fences and modifications to the front of the property. In the case of apartments some owners have included the balcony as part of the living room. Owners of houses may have constructed terraces or gazebos. Make sure these don't challenge deed restrictions or you may be liable for their removal at a latter date. Ask your RE agent what is listed with the property.
Usual items listed are appliances, curtains, etc.
However, that is not always the case. If you make an offer for the home make sure these items are spelled out. As Puerto Rico is in area prone to hurricanes, having these facilities is convenient and may be necessary. El proceso de compra siempre es complejo. Estudie las v as de acceso.