When did the Dingles - Zac etc - buy the house. I ask because as I remember it Mandy Dingle bought it for approx £6000 which was a knockdown price that one of the Tates (probably Chris) didn't think she would be able to raise but had to stick to when she did raise the money.
I can't remember Zac (and Lisa) buying the house, which could mean that Debbie doesn't own the deeds either.