The first two winters that I had chickens, I did not keep extra lighting on or did I provide any additional heating. Out of the thirty hens I had at that time, we would only get three to six eggs a day. The third winter, I kept lights on for fourteen hours a day, and added heat to their coop. I know there are alot of different opinions on this matter, but the results were out of the thirty hens, I maintained 85% production which was a tremendous difference. If you are relying on production of eggs to sell, then you might want to consider these alternative measures. You also must keep in mind, that the cost of lighting and heating does not exceed the income you have for the additional egg production.
We love to be able to go out and see our girls happy in their lighted and heated coop and happily producing eggs!