When should we buy? - Energy Saving Ordinance from May 1

Hello dear people,

My wife and I are about to buy an older farmhouse soon; it is already decided that it will be this one because it is located in the immediate vicinity of the parents' house and land...

My question: Starting May 1st, this new energy-saving regulation comes into effect, and the seller would like the purchase contract to be completed at the notary by then... of course, this way he doesn't have to pay for the energy certificate. On the one hand, that suits us just fine, the sooner we can start renovating, but does that have disadvantages or rather advantages for me, or what would be better—buying before May 1st or rather after? Some of you are surely more familiar with this level than I am.
Thanks already for your info,

Regards, Chris

Does the timing of the purchase change your decision? Since you definitely want to buy and then renovate, just do it directly and don't wait. An energy certificate is, by the way, just a sheet of paper with theoretical values that can only say limited things about YOUR energy consumption.

Yes, that's true, it doesn't change my decision, I just had concerns that once the house is evaluated, sooner or later requirements could come up regarding facade insulation, ...! At the moment "nobody" knows what values each house has?! As far as I know, from May 1st there's only the change that heating systems from "before the reunification" have to be removed... but that doesn't matter in my case, as the oil heating is about 15 years old and we want to install a new wood gasification stove anyway! What opinions are there about the possible later requirements?