Isobenefit Urbanism is a libertarian paternalist planning approach based on a morphogenetic code inducing a 15-minute walking city where one can reach within 1km: natural land, shops, amenities, services and places of work. It does it by being semi-liberally driven by market forces and genius loci. The urban development and growth follow spontaneous or desired functional morphological patterns and densities across the urban planimetry, with infinites outputs satisfying the Isobenefit Urbanism design objective function. The latter is to reach an evenly walkability across every urban area, where everyone from everywhere can walk toward natural land, and her daily activities. The generated urban forms and spatial ratio distribution between cemented and green lands would have the potential to reduce urban heat island effects, flooding, particulates, commuting time, physical and mental urban illness linked to pollution, noise, forms of stress, car accidents. It also opens interesting discussion and simulations of real estate values distribution deserving investigations. A few simulations from an alpha version of this cellular automata code will be briefly discussed from a planning, environmental and economic issues
