OTTAWA - The Bank of Canada is again underscoring its concerns about rising household debt and home prices.

And it's not necessarily mortgage debt the central bank is most concerned about -- it's the money Canadians borrow by using their homes as collateral.

The central bank says a majority of this borrowing is spent on consumption and home renovation.

Citing a series of research papers, the bank suggests that the financial security of many Canadians is built on a house of cards -- the steep increase in the values of homes. If home values correct, that would leave households with a huge debt load and less equity to back it.

The papers repeat already published data that household debt as a ratio of disposable income has risen steadily in the past 30 years and has gone from about 110 per cent to more than 150 per cent in the last dozen.

But the papers also show that the debt to equity ratio has also risen.

And it also notes that despite the equally steep increase in home prices, affordability has remained relatively constant due to rising incomes and falling interest rates.

The bank does not warn of a potential crash as occurred in the United States, but it does worry about households being caught in a bind if an economic shock occurs and that lower-income families are most vulnerable.

Economists have been split about the seriousness of Canada's debt issues, although all warn that households cannot keep borrowing at levels above their growth in income.