The report concerns design aspects for the recently proposed solar barometric distillation technology for seawater desalting (SW-SBD) via underground barometric layout. One-stage and two-stage SW-SBD desalting plants applying a solar vapour thermo-compress ion distillation technology are specifically analysed. Feed brine at subatmospheric pressure is made to flow in vacuum solar collectors of simple design and construction to absorb solar radiation and to deliver the water vapour which drives a vapour thermo-compress ion distillation process at operative temperatures below 100 degrees C. The proposed SW-SBD desalting technology has a good energy efficiency and promising technico-economic features. Field research on SW-SBD prototype plants is necessary to bring SW-SBD desalting technology to its full technological development.