19. A proponent obtaining a permit for a lesser period might need to consider whether the project is worth proceeding with on that basis. That is no different from the situation that a proponent faces in relation to any permit granted. The Responsible Authority or the Tribunal may decide that the permission sought should only be granted subject to certain conditions. It is for such authorities to impose such conditions as are necessary, reasonable and justified in planning terms. The result may not be attractive, or even feasible, in commercial terms. The commercial assessment is a matter for the proponent. It is for the proponent, having got the permit, to decide whether to act on it. The proponent may decide not to do so, indeed may decide that it would not be commercially viable, or a wise investment, to do so. As I have said, it is a question for the proponent, and not for the Responsible Authority, to concern itself with such commercial matters. The Responsible Authority should only impose such conditions that are necessary and justified in planning terms, but it should not refrain from doing so on the basis of non-planning commercial considerations.