Being framed...

First frame complete

The complete ash frame will sit in custom-made hot dip galvanized mild steel foot plate which in turn will be chemically anchored into the existing low height brick wall.  This steel bracket keeps the timber frame away from any potential moisture leaching out of the wall.  This in turn will prevent the frame from decay.
The solid ash frame could last for hundreds of years, by which time the sea may indeed have risen to engulf it (thanks to global warming).

Second frame on its way