My CU does not have RCD for lighting circuits

Now under the 18th Edition regs, if you had any additions or extensions to the lighting circuit then an RCD must be provided. In your case it’s tested as seen. Therefore the lighting circuit will be a Code 3-Requires improvement.

Hi , yes that statement is still valid as per regulation but if you are doing a new rewire all circuits must be rcd protected.

Your electrical installation must comply with the current version of BS7671 at the time that it was installed. Any additional works carried out on the installation (excluding maintenance such as replacement of a socket or light fitting) must comply with the current version of BS7671 today. It should be noted that an RCD is a fancy name used to cost you additional money, but also reduces the amount of electricity that can travel through your body, child or pet saving their life and trips preventing many fires during faults. Always install RCD's unless it really is not practical to do so. Your tester should be able to install one cost effectively as he is there anyway and testing it anyway.

Under current regulations, all new/altered circuits must be protected by a 30mA RCD. As stated above, as long as the installation complies with the regs for when it was installed, then it will still pass with a C3 note saying the circuit requires improvement. We would always recommend you protect all your circuits with an RCD regardless of regs. The device protects from line-to-earth faults greatly reducing the risk of electrocution. Especially important if you have IP rated lights in bathrooms or outside!