Without knowing exactly, I see it like nordlys: nobody cares. But it is important that you comply with the [Energieeinsparverordnung], otherwise there are huge fines threatened, if someone does care.
Ok so basically it is just a renewal of the roof covering, so maintenance. The only thing that concerns me is the doubling up of the beams. Necessary in order to comply with the [Energieeinsparverordnung].