Carpet seams and seam locations are probably the biggest challenge in our industry. Since carpet only comes in certain widths, it is very likely large rooms will require at least one seam.
Several factors need to be considered when deciding your seam location such as, furniture placement, directions of light source, doorways and traffic areas, number and length of seams and how it may affect seam placements in other rooms.
There is usually no perfect scenario and often times you must compromise one of the criteria for another. A properly constructed seam is generally still noticeable, but depending on what style and color of carpet you have, it may be more or less noticeable.