Additivity of the support norm for tight contact structures A corollary of Haken's Theorem gives that the minimal genus of Heegaard splittings of 3-manifolds is additive under connected sum. In this talk I generalise this result for contact 3-manifolds. There is an adapted version of Heegaard splittings for contact 3-manifolds, that splits up a contact 3-manifold into two tight handlebodies with a prescribed contact structure near their boundaries. These contact Heegaard splitting are in one-to-one correspondence with open book decompositions. There is a simple homological counterexample of Ozbagci, showing that the minimal genus for these contact Heegaard splittings is not additive in general. After introducing the basic notions, I describe the main idea of the proof, that the minimal genus for contact Heegaard splittings of tight contact structures is additive under connected sum.