Hi Alanm,
If you try to protect your light equipment and also electrical consume and if your electrical Panel have for security I.D. (Interrupter Differential) whom is also one for Lighting and one for Sockets then, you can use an Photo-Sensor (Crepuscular Sensor or another electronic photo-sensor) and electric Contactor connected in serial circuit of Lighting I.D. to electrical Panel. This will work Off for Lighting house in a Sun day and On for all circuits when begin the Night automatically. Also where is places in a house without windows (like a Bathroom for example) you can separate this circuits from electric Contactor to let them in old connection in electrical Panel and other's circuits what you don't need use in Sun day make a new connection to the electric Contactor. The Sensor will be connected in serial connection with Coil of the electric Contactor for command this Off and On. Also, you can call an Electrician with Autorization if you can't do this work alone.