Natural Materials

We now make most of the materials use for building. But one natural material, wood, is still very important to us. Wood is strong. The strongest parts of plants are the stems, trunks and branches, and these are made of wood. Wood can make building strong, too.

In some ways, buildings are like trees. A tall tree has to be able to bend in the wind, or in the end it would break. A skyscraper also has to be able to move a little, although you do not notice it.

Trees have roots under them to hold them up and stop them falling over or sinking into the ground. Buildings have layers of concrete, or foundations, underneath them to do the same thing.