  Topological insulators (TIs) are an important family of quantum materials
that exhibit a Dirac point (DP) in the surface band structure but have a finite
band gap in bulk. A large degree of spin-orbit interaction and low bandgap is a
prerequisite for stabilizing DPs on selective atomically flat cleavage planes.
Tuning of the DP in these materials has been suggested via modifications to the
atomic structure of the entire system. Using the example of As$_2$Te$_3$ and
ZnTe$_5$, which are not TIs, we show that a quantum phase transition can be
induced in atomically flat and stepped surfaces, for As$_2$Te$_3$ and ZrTe$_5$,
respectively. This is achieved by establishing a framework for controlling
electronic properties that is focused on local perturbations at key locations
that we call sub-structural elements (SSEs). We exemplify this framework
through a novel method of isovalent sublayer anion doping and biaxial strain.
