Building in an area with a high level of subsidence

What insurance companies fear is — of course — the unknown, as that is where their risk lies.
I am living in a city suburb that is regarded by insurance companies as an area of high level subsidence. I am fortunate to have a very large garden as I am on a corner site. I recently successfully applied for planning permission to put a second home on a portion of the site. I intend to build a new home for myself and to sell our old home (I’m not setting a precedent, there are other homes in the area that have done likewise). This time, I would like to be in a position to take out comprehensive home insurance — it’s currently only available to me with a subsidence exclusion. I spoke to another homeowner who also built on a corner site and they said they overcame this problem by using a floating foundation. I don’t know what this involves. Is it costly? Is it complicated? Can you advise?
Many thanks,
Dorothy O’Neill.