Materials

• Traditional shutters were made of wood. The best wood for shutters is cedar, because it is lightweight and rot resistant. Decorative shutters are often made out of vinyl or plastic because these are cheaper to make and low maintenance. Functional shutters can be made out of many different materials, including metal, plastic and various species of wood. Materials that are nonporous, durable and resistant to the effects of wind and rain are the most suitable for shutter construction.
  
  

Louvers

• Most shutters are designed with louvers built into them. A louver is a horizontal slat of wood that is set into the shutter at a diagonal angle so that it sheds water. Some shutters are built with fixed louvers while other, more expensive shutters are built with movable louvers. The latter kind of shutter can have the louvers set to shed rain when they are open and moved to face the other way so they can continue to shed rain when the shutters are closed. Shutters with fixed louvers shed rain only when they are closed.
  
  

Functional Shutters

• Shutters originated as functionally protective features on the outside of a house and only became decorative over a period of years as people became accustomed to their appearance. In years past, window glass was both more expensive and less durable than modern glass, so installing shutters was worth the trouble to have sturdy shutters that could be closed over the windows during bad weather. Many older homes still have functional shutters on them, although they are less commonly used than in times past.
  
  

Decorative Shutters

• As newer houses were built with newer window glass that didn't require as much protection, people still wanted the look of older houses and so began installing shutters that had no function other than a decorative one. This type of shutter is usually screwed directly to the wall of the building next to the window and doesn't have the capacity to open or shut. As people's memories of what these objects were originally for fades, shutters become so abstracted from their original function that they are often not even the same size as the window they are next to and therefore wouldn't work even if they could be moved.