The size of an orangery you can build without planning permission is subject to "permitted development rights," which may vary based on your location and the specific regulations set by your local planning authority. In England, under typical permitted development rules, you can generally build a single-storey orangery without planning permission if it meets the following criteria: The orangery does not extend more than 50% of the total area of your property. The height of the orangery does not exceed 4 meters. The eaves height of the orangery does not exceed 3 meters, if it is within 2 meters of the boundary. The orangery is not forward of the principal elevation (the front of the house). The orangery does not include any verandas, balconies, or raised platforms.