In terms of design, orangeries have a lot more brickwork than conservatories. You can expect to see structures such as stone pillars, flat roofs and glass lantern roofs. This makes them far better insulated, as the stone is better at retaining heat than glass. On top of this, the windows are usually double or triple glazing to further block heat escaping through the windows, and roof panels that do the same for the roof. To further increase insulation, you can have heating/ventilation systems installed in the walls, and also in the floor. Because of these features, Orangeries are typically more expensive than conservatories. Conservatories, on the other hand, have traditionally been made up almost entirely of glass. This has made them more difficult spaces to regulate heat in both the colder and warmer months. Conservatories are generally smaller and designed with a more contemporary look. In some instances, a conservatory and an orangery can be constructed with a flat roof as opposed to a glazed roof, although people are increasingly choosing to add roof lanterns to their existing flat roof in order to allow more natural light into their space.