  We construct solvable models on the honeycomb lattice by combining three
faces of the square lattice solvable models into a hexagon face. These models
contain two independent, anisotropy controlling, spectral parameters and their
transfer matrices with different spectral parameters commute with each other.
At the critical point, the finite-size scaling of the transfer matrix spectrum
for the honeycomb lattice models is written in terms of the quantities obtained
from the finite-size scaling of the square lattice solvable models. We study in
detail the phase transition properties of two models based on the interacting
hard square model and the magnetic hard square model, respectively. The models,
in general, can be extended to the IRF version of the Z-invariant models of
Baxter.
