About 20% of all energy utilized worldwide is allocated to regulate the temperature of buildings through heating and cooling in response to seasonal changes. Numerous cutting-edge, low-carbon-footprint innovations have recently been demonstrated to assist resolve this issue, including passive radiative cooling and sun heating. Their accessibility is nevertheless constrained to particular seasons or climate zones by the steady and one-sided control of temperature. Here, taking advantage of recent breakthroughs in photonic manipulation and radiative heat transfer technology, we propose phase-transition metamaterials with dynamically passive and radiative thermal regulation capability for temperature control that can be scaled up for application in buildings. At a critical temperature, the sun absorptance of this metafilm can self-modulate from 0.9 to 0.18 as a result of temperature changes. This metafilm is made of reflective silver (Ag) thin film on top of polyethylene (PE) film with vanadium dioxide (VO2) nanoparticles embedded in it. By varying the volume percentages of the VO2 nanoparticles and the PE matrix thickness, this metafilm’s optical performance can be tailored. We model the inactive dynamic thermal regulator’s equilibrium temperature response to diurnal temperature swings. The industrial film extrusion approach has the potential to produce the nanoparticles embedded into the polymer structure, and the physical vapor deposition method can deposit the Ag thin film scalably, both of which are encouraging for scale-up deployment. This passive radiative heat thermal management technology can be potentially applied to regions with extreme annual temperature fluctuations.