What is the minimum safe distance from a house and an electric transformer 13.8 KV?

The transformer enclosure should isolate the transformer sufficiently from the environment. I believe OSHA specifies 2 feet, 1 inch as the minimum appoach distance to 13.8kV, so I suppose a transformer could be put this close to a building and still be safe. My guess is there are codes in place in your local area that prevent this and specify some greater distance.