Classical design proportions revolve around the concept of
"the golden mean". The mathematical ratio between the larger side and
shorter of a rectangle is 1:1.618.
This has been recognized by the Greeks,
Egyptians and Renaissance artists and designers.
So before designing your house you should first make a plan where all the rooms and their
approximate sizes are fitted in, according to your own needs.
At this point you now know where the rooms are all going to go, now it is
time to size and shape each of the rooms. Note that here, size is the
minimum size to accommodate the activity. Because the rooms have to fit
together in one package and is constrained by structural considerations, there
is a lot of give and take as to what the actual size of a room will be.
This stage often involves much compromise, and a lot of drawing trying to get
everything to fit and work together, and is an area where an experienced architect
or designer is much better at this than anyone else.