Just to remind you (needless I am sure), the current convention is that banks need in general to hold equity capital equivalent to around 10% of their loans.
The outcome, eventually, was a rule by which a company can keep a special-purpose vehicle off its balance sheet as long as an independent third party owns a controlling equity interest equivalent to at least 3% of the fair value of its assets.
Most dramatic has been Britain: house prices have risen by more than 25% over the past year, and Goldman Sachs estimates that mortgage equity withdrawal was equivalent to 8.5% of personal disposable income in the fourth quarter, more than at the peak of Britain's housing bubble in the late 1980s.