I used to live in a house in North London that was set back off the road and not easy to find. On the few occasions I had to call an ambulance (genuine ones that were worthy of an ambulance - honest!) I always made sure I told the nee-naw control exactly how to find us - but I learned from experience that message did not necessarily get passed on. I also made sure that if possible someone was sent out to wait for the ambulance on the road and show them where the emergency was. These days I have moved North and work at a GP practice in Cheshire, and have learned up here that ambulances don't always find us easily - even though we are on a main road and call an ambulance more often than the average household does. But I do feel for you rushing to find that child, and I do agree that signs should be bigger. Perhaps a letter should be sent to the letters page of a prominent architect's magazine if they have one . . . a copy of this blog would be a good example for them to print.