Is it more energy efficient to heat your house up and let it cool down or maintain a constant temperature?

I live in the UK so it is never ridiculously cold but I do need to heat my house over winter. I have a thermostat and can control my house temperature. Currently I have my heating so my house never gets below 10degrees centigrade at night (about 50 degrees to you americans!) and heat it to 17 degrees C (63 degrees F) in the morning, I then let it drop to 14 degrees C (57 F) throughout the day to be pushed back up to 17 or 18 (63 F) in the evening, I then let it drop back to 10 (50F) at night… Is this method of heating my house more or less energy efficient than if I kept the house at a minimum of 14 degrees C at night too or is it best to heat the house up like this every morning?