This designation is usually used to classify a house that is spread over two floors , with an interior staircase that connects them.
This concept is mostly used in apartments, since the houses are usually already distributed in this way. Duplex apartments are in great demand in cities, as they allow replicating the concept of housing in environments with high urban density.
The possibility of dividing the apartment functionally, distributing the rooms on the upper floor and the leisure and dining areas on the lower floor, are an element of great value for the property, hence the Duplex apartments are easily sold .
A Duplex apartment can have this characteristic from scratch, if it has been built as such, or else the result of a remodeling and expansion project. In this case, some care should be taken as there are many apartments that have been expanded and connected to the attic without complying with an architectural project duly authorized and licensed by the city council. This can cause discomfort if you need to buy the property using mortgage loans, or if the same situation occurs when you want to sell it one day later.