Hi. We live in an older house and we are doing a loft conversion. We do not have an SPD on the connection to the grid and the builder's electricians insist that we must have one, otherwise he can't sign the certificate, but he doesn't want to give me a reason. We have a few consumer units under the stairs, next to the meter and I do not think there is enough space for him to do any changes now. I want to have an SPD installed, but not right now as we plan to do some other changes in the house soon and I do not think it is worth paying for something now just to have it changed in a few months. Can someone please tell me whether there is a legal requirement to install an SPD when doing a loft conversion? (the house is a semi-detached with a looped connection and the electrician didn't even have to connect a new loop to the consumer unit as this had alreay been done a few years ago when we had some other electrical work done in the house). Thank you