Where there is an IVA and poor equity there are often problems with lenders because under the terms of the IVA, your creditors are due a proportion of the increase in value of your property at the end of the 4 years.
For example, if they settled for 25p in the �1 then they would be entitled to 25% of any increase in value of your property over the 4 years of your IVA agreement.
This makes it difficult for a lender to be sure of what they are securing the lending on.
I think this can only be done by consolidating and paying off the IVA.