Hello. I am Wigeon's friend who had her homebirth at Kings. I think the Trust is pretty well known for its homebirth success so you may already know about its methods. I think having very strong community midwife support really helps woman feel secure in choosing homebirth so you clearly have the right foundations in place!
I wanted a homebirth from the outset as I wanted guaranteed access to a birth pool and had heard too many horror stories about postpartum care in hospitals. So I was one of the people who responded at my booking-in appointment with an enthusiastic 'yes' and had mustered my arguments in advance if my BMI of over 30 were questioned - it wasn't at all, in the end. During my pregnancy my midwives were very clear that a homebirth wasn't guaranteed until my 37 week sign off, and that with first time mothers, they had a very low tolerance for transfer. In the end I had four days of non-dilating but frequent and intense contractions - the kind that would have had me hopping to and from hospital if that had been the plan. In my debrief, I was told that in hospital my waters would most likely have been broken and I would have ended up with a C section because my baby took her time getting into position. Once she shifted a bit, labour was five hours from start to finish. I had visits from midwives throughout this and had lots of useful suggestions on position. I was also given their blessing to get into the birth pool after a bit so I spent two days sitting in the glorious warm water watching TV between contractions.
Because of the high homebirth rates in my area, I know lots of women who had or planned homebirths, which does normalise it to some extent. My NCT group were all slightly horrified at my plans, but at least two of them are now planning to have homebirths if they have a second child. So I think you do achieve a sort of critical mass where it becomes a natural option. I think my keeness for the whole thing was one of the reasons Wigeon ended up planning a homebirth? Being so close to the hospital helps too, and the fact that Kings doesn't have a midwife led unit at the moment, although I gather one is planned, so the choice is a bit more stark.
In terms of selling points for you, I loved, loved the idea that I would know the midwives who delivered my baby. In the end, I knew one of the two that was there, and I knew she felt personally thrilled that we managed not to transfer and had the birth I wanted. So perhaps you could emphasise that point, and refer to the evidence that women do better with that continuity of care. I was also given the leaflet which included, and I think rather promoted, homebirth. I don't know who produced it.
Finally a friend of mine, due just after me, was very against all mention of birth full stop. She told me I was insane to plan a homebirth. She refused to read anything about birth etc. But my ravings about my hypnobirthing course persuaded her to attend one herself and that completely turned her around, and she ended up planning a homebirth herself. So perhaps you could plug hypnobirthing a bit? It's easier to do at home I think, and you are also more likely to have informed and/or supportive midwives. The course I did was aimed at women having babies at hospital actually, so I don't think there was any pressure to have a homebirth, but it does create more confidence in the birthing process and a women's ability to cope, and both those things are necessary I think to think of homebirth.
Good luck! My birth was the most wonderful experience and I'd love more women to have the chance to experience it. Sorry for the long post.