Cedar Construction

Cedar lasts much longer outdoors compared to any other type of wood. Other woods like pine may be cheaper, but they won't last in the sun and rain like cedar.  

If it is refinished every few years it can look like new for decades.  If it is left to the elements it will slowly turn grey, but stay solid for years.  
 
Recently, chairs made of recycled plastic have become popular.  They are a great choice if you are looking for colour or you want to avoid maintenance.  However, plastic chairs do tend to fade over time, they are also extraordinarily heavy and available in limited designs.