If you can't comply with the conditions of your IVA, you might have no other alternative than bankruptcy. However, if you're trying to keep your home, you might want to look into the possibility of applying for an FTVA (Fast Track Voluntary Arrangement). You have to go bankrupt first but, if you can then get an FTVA, your bankruptcy is annulled and you might be able to keep your house. To do so, you have to convince your creditors that they'll get more money from the FTVA than they would if you remained bankrupt. That would probably mean you'd need to enter into an agreement to continue making repayments for considerably longer than the 3 year bankruptcy period but it might be appropriate for your needs.
To learn more about bankruptcy and FTVAs, start here:
http://www.insolvency.gov.uk/
Chris