  We construct the $\Phi^4_3$ measure on a periodic three dimensional box as an
absolutely continuous perturbation of a random shift of the Gaussian free
field. The shifted measure is constructed via Girsanov's theorem and the
relevant filtration is the one generated by a scale parameter. As a byproduct
we give a self-contained proof that the $\Phi^4_3$ measure is singular wrt. the
Gaussian free field.
