In the case of ad hoc wireless networks, a packet transmitted by a node is received by all nodes in the neighborhood and within RF range. One of the problems is to minimize the total number of forward transmissions for broadcasting. Though this problem is NP-complete some approximation approaches such as Gossip [4] and dominant pruning [9]have been proposed. We propose a new scheme for ad hoc networks based on neighbourhood information and a modified version optimized for sensor networks.We define an efficiency metric and use it to compare the different broadcast schemes. We have simulated our approach using Scilab and verified that our theory is correct.Finally we also compute the energy consumed by the network and show how it can be minimized.