Dordogner

We currently own 2 houses in France, both of them purchased jointly in our current single names.  We are now planning to get married in France (as advised by the notaire). We are also resident in France. We have now been informed that there is a large sum to pay to re-register the houses, even though we have chosen to get married under the communaute universelle regime. I was under the impression that the houses would automatically become jointly owned due to the communaute universelle. There are no children to consider and we are unable to have children in the future. The sum quoted by the notaire is close to 2000 euros.  Has anyone else experienced this cost?  Our notaire when we booked the appointment with her was unsure how the procedure worked and had to make enquiries.  Has she got it right?