David Halliday
Colin, There are many different types of sandstone walling. I am assuming that it's rubble walling ( rough pieces of stone built ). If all the stone is available for rebuilding then a rate of £ 130.00 per square metre would be the going rate.this includes pointing and lime being used. Colin make sure your chosen contractor only ever builds stone with lime and not cement as cement is non porous and does not allow moisture to pass through the walling this causing various problems! Good luck with your project. Dave.