I have a friend who is trying to buy a

the only thing to do to be the sole owner of the house, without taking risks, is to get a divorce, before buying it

Back in the early 2000's, I bought my house in Italy.   We decided it was easier for me to be the sole purchaser, although both my wife and I attended the signing at the Notary's. 

He was OK with her not being a purchaser,  but asked that my wife countersign each page of the documentation to indicate her agreement with me being sole owner.

Ugo is right.  If he buys before the decree absolute then the wife is automatically 50% owner.    

alanh -presumbaly you are married in separation of goods?  If you are in communion of goods (default state for UK and Italian residents) she is owner of 50% whether you like it or not. 

Alah,

Modicasa is right, in Italy there is a law, originating from Roman law, according to which the agreements <contra legem> have no legal validity -

Now, the law in Italy establishes that everything purchased, even by donation, within the legal situation of the marriage, becomes property, 50/50 between the two spouses -

Everything you have written and your wife has signed in good faith, is configured as a pact <contra legem>, therefore of no legal validity -

Aimeh, your house is 50% owned by your wife, even though your wife doesn't want it. And the only way, for you to become the owner of the 50% of your wife's competence, is that she sells it to you, with a notary deed.