How Much Could We Borrow?

We need to take out a loan to make home improvements and would like to consolidate our other debts into one payment at the same time. We have heard about secured debt consolidation mortgages and are trying to figure out if this would work for us. How much would we be able to borrow using this process? I am not sure whether we would be able to borrow enough to accomplish both goals at once. I think we should take care of our debt first and then make improvements to the house, but my husband wants to try to take care of both at the same time.