To the extent that a condominium unit or common element encroaches on any other condominium unit or common element, whether by reason of any deviation from the plans in the construction, repair, renovation, restoration, or replacement of any improvement, or by reason of the settling or shifting of any land or improvement, a valid easement for the encroachment shall exist. This section shall not be construed to allow or permit any encroachment upon, or an easement for an encroachment upon, units described in the master deed as being comprised of land and/or airspace above and/or below said land, without the consent of the co-owner of the unit to be burdened by the encroachment or easement.