Wood you Kindly? (Wood):

Some puns are simply irresistible. Wood is required for several buildings in Empires & Allies, and important ones at that. Not only is Wood needed to create Houses, but you'll need the tree to create Military and Government Buildings, too. Now you can see why this resource is vital. While clearing Trees and Bushes from your island Empire provides tiny amounts of Wood in exchange for Energy, building Lumber Mills is the way to go. In exchange for Coins, these buildings can produce much bigger amounts of Wood that are always guaranteed.