Suppose you bought a new house in the year of 2010. Then the price of the house in counted toward the 2010 GDP. Say then you live in the new house in the following years. So in these years, the GDP includes the housing rental you paid yourself. But then why is it not an overcount? I mean, when we counted the house price into GDP in2010, we have already counted all the utility of the house in one year and there is no need to count the de recurring rental.