• Window grilles can be decorative or defensive.grille image by chantal cecchetti from Fotolia.com
  
  A window grille is the wood, plastic or metal that sits on the window itself and divides it into panes. While mostly used for decoration, these can be purchased for safety and can prevent a burglar from entering the house. These grilles come in many different styles and either mount on the glass, in the window between panes of glass or hold individual panes of glass in the window. All windows may not have grilles, and certain types of windows do not need them. When choosing a different window grille, think about the style of the house and what would look best with that style.
  
  

True Divided Light

• Divided lights are typically found in older homes and in historic architecture. This style creates a framework within the window that holds small, individual pieces of glass. The benefit to this grille is that if a single panel breaks, you only have to replace that pane instead of the whole window. The drawback is that these windows are not very energy efficient and are usually only the thickness of one pane of glass.
  
  

Simulated Divided Light

• Simulated divided light (SDL) grilles are pieces that fit on the inside and outside of a solid-pane window and create the illusion of true divided light (TDL). These are a permanent decoration mounted on the outside of the window and can be permanent on the inside. They will look like TDL but offer the energy efficiency of a solid pane of glass.
  
  

Between-the-Glass

• The between-the-glass option offers you the divided panel style that is more energy efficient. This is two panes of glass with the divider sandwiched between them. This design makes it remarkably easy to clean both inside and outside of the glass without worrying about the grille.
  
  

Snap-On

• This style sets on the inside of the window and is held in place with tiny nails that just barely break the surface of the outer frame. These grilles are removable and make the window easier to clean, and can be changed to suit the tastes of the homeowners.
  
  

Patterns

• There are many patterns of grilles that can be found in different styles of homes. These can be both TDL or SDL depending on the age of the window. The traditional style, also known as the colonial, divides the window into equal-sized panes of glass. The top row divides the top pane evenly and does not divide the bottom. This is typically used when there are large picture windows and you don't want to break up the landscape with a grille. The top pane is then much smaller than the larger bottom windows.
  
  

Wrought Iron and Steel

• Used initially for protection, this style has evolved to blend in with the architecture of the building. Some styles available are a full window mesh, a vertical pattern that divides the entire area equally into squares; large spikes braced by parallel bars that run horizontal; and bars that divide the window into three parts. Some of the attractive options include bars made to look like vines with leaves and flowers, spirals of different shapes and sizes and vertical bars with decorative swirls and designs on top.