The lots cannot be rotated. I think this is on purpose....had you ever noticed in the Sims 3 how sometimes terrain paints are "shifted off" to one side and not where they are supposed to be? It is because the lot was not oriented the exact same way as when it was created. By having all the lots oriented in one direction that doesnt move, that wont happen.
We can move the house and rotate it, but....yeah...have to redo the landscaping and such. Which I would rather do than have to rebuild a house from scratch because it ended up being too close to the street. :)