Household investment, that is investment in consumer durables and housing, leads non-residential fixed investment over the U.S. business cycle. This observation represents a potent challenge to real business cycle (RBC) theory. First of all the theory has been unable to account for it. In addition, research suggests the observation is driven by monetary shocks, supporting the view that these shocks play a leading role in the U.S. business cycle. This paper shows that RBC theory is consistent with the investment dynamics after all. It does so by generalizing the standard home production environment to take into account the fact that household capital is useful in market production.