Pricing for building a new home

Just trying to see if anyone has a range of what a builder would charge.

We are looking into buying a house that is on a big piece of property. We would basically renovate that house and build on it. (probably only saving a few walls) so its not considered new construction.

Anyone have a clue on the price per sq footage. Im hearing its about 100 per sq foot. Am i totally off

Re: Pricing for building a new home

We have a friend who is an architect. He has said, since Katrina, building supplies have gone up in price (lumber and copper specifically). $100/sq ft is a pre-Katrina price. Today it would be $200-400 sq/ft (based on supplies you are interested in using)

but I don't have any direct experience, we asked him when we were considering expanding.