In case you missed it, there was a recent article in the Wall Street Journal that discusses new construction cost estimates. The article mentions one site that provides an online calculation: http://www.building-cost.net/. Like all such calculators, it can provide a rough estimate at best. However it is still a very useful place to start and to understand the variables involved. According to the site - "you can develop a home construction or replacement cost that considers all the important variables: materials used, design features, quality, size, shape, heating, cooling and geographic area."