If the annexe has its own fusebox separate to the main property, you could just have the installation in this part of the property tested
Answered by Sarah, Electrical Safety Expert
If the annexe has its own fusebox separate to the main property, you could just have the installation in this part of the property tested. However, if the power comes from the property's main fusebox you would need to have the whole property tested. Our recommendation would be to have the whole house done for your own peace of mind. You can find a registered electrician near you to carry out the work here.