We can talk all day long about ‘functionality’ and ‘practicality’ and the reason why one needs to consider such matters is because once such considerations have been taken into account they can be forgotten and you can focus on the more artistic matters that make a house a home.
If we use a metaphor – a writer needs a structure before they start a philosophical essay because without it excellent ideas will remain disconnected and the reader will become alienated. However, if a writer has a clear plan their excellent ideas will have a structure within which the reader can understand their profound meaning. With a home – if you sort out the structure in your head before making a purchase you will be ahead of the curve as once you are given the keys you can start to implement the artistic ideas that define your personal style and that will turn the shell into your home.