The reaction of the chiral dipeptide glycyl-L(S)-glutamate with CoII ions produces chiral ladders that can be used as rigid 1D building units. Spatial separation of these building units with linkers of different lengths allows the engineering of homochiral porous MOFs with enhanced pore sizes, pore volumes, and surface areas. This strategy enables the synthesis of a family of isoreticular MOFs, in which the pore size dictates the enantioselective adsorption of chiral molecules (in terms of their size and enantiomeric excess). ; This work was supported by the MINECO-Spain under the project PN MAT2012-30994. I.I. thanks the MINECO for the RyC fellowship and K.C.S. is grateful to EU for the Marie Curie Fellowship (300390 NanoBioMOFs FP7-PEOPLE-2011-IEF). The authors thank the Diamond Light Source for access to beamline I19, which contributed to the results presented herein (MT8477). X.R. thanks for an ICREA Acadèmia award. The project “Factoría de Cristalización, CONSOLIDER INGENIO-2010” provided PXRD facilities. ICN2 acknowledges support of the Spanish MINECO through the Severo Ochoa Centers of Excellence Program under Grant SEV-2013-0295. ; Peer Reviewed