Family rooms are notorious for having many doorways, windows, and frequently a fireplace. Where do you put the TV so you can enjoy the fireplace and the TV? This is the one room that usually takes the most effort if there is a change to be made. Also, most of the TVs I see over the fireplace mantle are not at a height for viewing while sitting down. Be practical about the TV placement.
Over the years, several times a client hired me just after construction was completed. They thought “Now, we need an interior designer” and I thought, “If only they had hired me in the beginning, I could have avoided a problem prior to construction of their new home that would have made a huge difference as to function and aesthetics.