Sq.ft.cost to build a family home ?
Depends on where you are in the world, and what a "family home" consists of to you....you need to search for local information to where you are
Varies from city to city, country to country. Depends upon where the home is located and how desirable that location is - in town, suburbs, country or slums. Depends upon the style of the home and materials used to build it. Big difference between wood, stone or brick for example. Big difference between different types of tiling and linoleum. High end plumbing fixtures vs low end plumbing fixtures. Surely you can see that no one could possibily answer you here. Call a realtor in your area and find out or a builder or architect.