Santorini

Hi all, Need advice from you all. I just collected my house key, and got the contractor to site the place for renovation work. He spotted that there was extenstion work on the electricitiy mains, (i.e. there is any small DB besides the main DB) and I am not sure was that approved by the HDB. I didnot notice that when I bought the house. what do you guys's recommendation, should I get the electrician the trace the whole house electrical work and submit to HDB if necessary? or can I assume that since HDB approved the resale unit, so it should be approved by HDB already. I think it is difficult to go and ask the seller right? I wasn't prepared to do such an extensive work when I bought the house. My house is a 4 room unit, I am not sure was the extension of electricity DB due to the installation of air-con, the entire house is air-conditiioned, 3 bed rooms + living room. The condensor is real big handing ouside the windows of master bed room. Appreciate your reply, thanks