We investigated with ab initio calculations the energetics of the most common silicon carbide (SiC) polytypes. We considered the (0001) Si face and the (000 (1) over bar) C face of 3C-, 6H-, 4H- and 2H-SiC. Our investigation reveals that the energy differences among SiC polytypes are enhanced at the surface with respect to the bulk. We discuss the relevant role played by the surface for the crystal growth of SiC. (C) 2011 Elsevier B.V. All rights reserved.