Have you asked him what exactly he thinks are the advantages of being in hospital?
Have you explained to him that you will have 1 on 1 care with a midwife in labour at home, and another MW once you're somewhere near giving birth to care for the baby, so you will have 2 on 1 care at home which is more than you can guarantee at the hospital?
Does he realise that the MWs are the same as the MWs in hospital, they have the same skills and training and can perform exactly the same examinations and interventions as they can in hospital?
Have you told him the MWs come with a whole battery of equipment, they have resus kits and gas and air, and some even have pethidine, and they bring monitors and everything they'll need - they don't just turn up and expect a bowl of hot water!
Have you tried explaining to him about the physiological process of birth, about how labour progresses better when you are more relaxed, and not under bright fluorescent lights?
Have you talked about the likelihood of any emergency happening and how far you are from hospital if you needed to transfer? Does he realise that even if you were in hospital, and needed emergency care, it would still take time to be arranged, and that arranging can be happening whilst you're on your way to hospital in an ambulance, so you will likely get treatment just as fast.
Does he realise the number of births that have some element of emergency to them are tiny? That there is no need to medicalise birth the way we do, and the likelihood of a plan, straightforward labour and delivery is much higher in every case than the possibility of needing emergency care (obviously I'm not referring to pregnancies where there is known to be congenital defects or whatever, I'm referring to straightforward average pregnancies).
I think you need to understand where he is coming from so you can explain the facts to him. On first glance everyone logically thinks hospital = safer, but that's not true for everyone, and you need to talk it through with him logically and with the facts so that he can understand, as he won't be as aware of all the facts as you are.