I will present a novel lipid backmapping methodology that uses mapping scheme and isomerchemical properties of a molecule. The method randomly places atoms around their corresponding coarse-grained bead and relaxes a system heavily based on bonded interactions while softened nonbonded interactions ensure no overlap between atoms during energy minimization. The developed method is simple to use with minimal input and powerful enough to construct a whole lipid structure from a single point. The method also imposes a set of dihedrals to keep the known isomerchemical properties of molecules during relaxation. I will also present an automated membrane builder based on our lipid backmapping scheme. The membrane builder constructs a plane bilayer membrane with protein chains embedded if given at Martini resolution. A series of short Martini simulations is carried out to equilibrate a membrane system. Lipids are transformed into atomistic resolutions based on the developed backmapping method, and proteins are replaced with the given input structures. Finally, phase separation examples inside membranes, prepared with the membrane builder, are shown at the atomistic level.