Real estate plays a major role in business cycles through three main channels. The first one is housing investment, the second one is a financial accelerator by which the increase of real estate prices leads to an increase in households debt for which its serves as a collateral. Finally, the third channel is a wealth effect. This articles explores these three channels in the main OECD countries relying on national accounts, wealth accounts and detailed consumption data. We show that the first channel differs among the various countries, the accelerator is found in all. The wealth effect is real in periods of rational bubbles.