Light itself, and minor domestic light fittings, are not subject to planning controls.
Nevertheless, if you are planning to install external lighting for security or other purposes, you should ensure that the intensity and direction of light does not disturb others.
If you live in a listed building, you will need listed building consent for any significant works whether internal or external.
If you are carrying out electrical work and fixing lighting to the outside of your house in England and Wales, you will have to follow the building regulations rules.
You should use an installer who is registered with a competent person scheme or if an installer is not a registered competent person, they can use a competent person to certify work as an alternative to seeking approval from a building control body.