Property capital gains and losses

[Debra]

Does anyone know how this works if you have both a loss and a gain in the same tax year when selling property?

I know that normally if a gain has been made the notaire deducts plus value tax and social charges from the sale proceeds.  

What happens if the gain you've made is a lot less than the loss you made on another sale in the same tax year?  

Can one be offset against the other and if so can the notaire allow that no tax is due on the second sale because of the prior loss or is it a matter of them taking the tax and charges anyway and the seller having to claim them back from the impots?