One of the most important factors to consider when it comes to interior design is functionality. The design of an apartment should be tailored to meet the needs of the occupants, including ensuring that there is sufficient storage space, creating a functional kitchen and bathroom layout, and placing furniture and other features in a way that maximizes the use of space. It's also important to consider the flow of the apartment, ensuring that there are clear paths for movement and that the layout is logical and easy to navigate.