Nothing to stop you purchasing a new property in just your name if you can meet the lending criteria, it will be much harder if you want a new joint mortgage and your husbands IVA is still on his credit file
He is already on his 6th year of IVA as he had to reduce monthly payments, could a new house - which I will buy on my name, be asked to be sold to pay back the debt if my husband won't be able to remortgage the old existing house to release the equity?
You have no liability to your husband's IVA and
no obligation to even inform his IP of what you are doing. Provided the funds are all your own and you earn sufficient in your own right to service the mortgage I see no problem.