  We construct a 5D $\mathbb{Z}_2$-symmetric model with three D3-branes: two IR
ones with negative tension located at the ends of an extra-dimensional interval
and a UV-brane with positive tension placed in the middle of the interval --
IR-UV-IR model. The background solutions for this geometric setup are found
without and with taking into account the backreaction of the matter fields. A
5D $SU(2)$ Higgs doublet is employed as the Goldberger-Wise stabilizing field
in this geometry and solutions of the 5D coupled scalar-gravity equations are
found by using the superpotential method. Within this setup we investigate the
low-energy (zero-mode) effective theory for the bulk Standard Model (SM)
bosonic sector. The $\mathbb{Z}_2$-even zero-modes correspond to known standard
degrees of freedom, whereas the $\mathbb{Z}_2$-odd zero modes might serve as a
dark sector. The effective low-energy scalar sector contains a scalar which
mimics the SM Higgs boson and a second stable scalar particle (dark-Higgs) is a
dark matter candidate; the latter is a component of the zero-mode of the
$\mathbb{Z}_2$-odd Higgs doublet. The model that results from the
$\mathbb{Z}_2$-symmetric background geometry resembles the Inert Two Higgs
Doublet Model. The effective theory turns out to have an extra residual
$SU(2)\times U(1)$ global symmetry that is reminiscent of an underlying 5D
gauge transformation for the odd degrees of freedom. At tree level the SM Higgs
and the dark-Higgs have the same mass; however, when leading radiative
corrections are taken into account the dark-Higgs turns out to be heavier than
the SM Higgs. Implications for dark matter are discussed; it is found that the
dark-Higgs can provide only a small fraction of the observed dark matter
abundance.
