100ft long, 16ft high, lived through all the frost, Beautiful. But now we redoing paving on one side and the wall on the other side has no foundation and needs to be replaced. Hedge growing beside it. ? do we replace it and or take our chances that it will live another bad frost winter? or will it die and we will have to rip up our new paving?
Where you are just replacing paving, you will not necessarily be digging out soil or reducing the level. There should be some sort of existing base for the paving and this might be re-newed, re-levelled, without causing much damage to underlying roots.
On the foundation side, dig as far as possible away from the base of the hedge and drive machinery as little as possible or not at all over the root area and restore the soil as soon as the foundation is poured and set.