As stated prior, that is a very broad question. There are many variables and factors that come in to play when determining what the price per square foot cost would be to build a new home. If you can be a little more detailed, I can elaborate further and be more specific with cost.
In Bangladesh, this is around 25 USD per sq foot, in Malaysia, it is around 35 USD per sq foot, in USA since the labor cost is high, it might be around 100 USD. I have a feeling some developers would ask 200 per sq ft (I would too, when I start doing it) but DIY may keep it around 100 USD I assume.
That's a very broad question with many possible answers depending on your meaning of construction. If you mean that you have a lot and you want to know how much it will cost to build a house on that house that could be from $150-200 SF.
If you mean how much is the selling price of a house it depends on location. The cost of land for a house may cost between $50-150 per SF of AC construction.
There are also soft costs that include architectural and engineering cost, impact fees and other related costs that may add another $15-20 SF of AC construction.
In my case I am a Realtor, architect, investor and developer so I am involved with all costs. Let me know if I can assist you.