Drain outside or inside?

It is common to place a 4" perforated drain around the foundation to direct water away from a house. We have always shown it to be on the exterior of the foundation on all home designs that our architectural design firm creates. However, the foundation contractor of the home I am building now said he normally placed them on the inside of the foundation on homes he did for other builders.

Foundation Drain

Since he mentioned it, I checked with some of the local contractors I know, and to my surprise, some of them said they install it on the inside and it was cheaper to do so. It seems logical to place the drain on the outside (see picture above) as you want to catch the water on the outside so it does not go on the inside.

The International Residential Code (IRC 2012) does not specify where to place the drainage. So that leaves it to the interpretation of local building official or builder. I would like to know where you think a foundation drain should be placed and why.