Transfer of both under construction flat and home loan taken for ot

Respected all, I am a married women. My brother booked a flat in an under construction building and took a 80% home loan for it after paying 10% booking amount. Rest of the 10% is to be paid on possession. Builder delayed it by 1.5 years. Now brother changed mind and want to buy a new ready to move in bigger house somewhere else and for that he wants to take a home loan. So he thought of transferring the previously booked under construction flat on me and my husband’s name and also wants to transfer the home loan taken for that to me and my husband. I am a housewife and my husband is a salaried person. Home loan is from icici bank. We talked to builder, he got convinced and ready to endorse the transfer. Now we moved to bank and talked to them for transfer of loan regarding the same but bank says this is not possible as home loan file is already on previous applicant’s name. I think bank is not understanding our concern correctly. Builder says its possible. Can you please suggest what is possible? Do we have to pay transfer fees or not as it is the transfer between blood relative but my husband is involved. Also please tell what will be the procedure for transfer of home loan?. Will the previous loan be closed or new loan starts or just the names on the loan gets edit because the ownership of the flat is changing.