You may want to consider using Anti-sun Tinted glass to reduce the glare and UV damage caused by the sun, particularly if your conservatory is South facing and gets alot of sun. Also improving the ventilation in the conservatory by installing roof ventilators will allow heat to escape and air to circulate in the room without the need to always open the windows and doors.
Visit the Mark George Conservatories website for more information on Conservatory Roofing Replacement