Abstract: A method for the production of a building construction with the aid of permanent formwork, comprising the steps of: placing formwork on a support, wherein the formwork includes a profiled formwork form with raised parts and lowered parts; applying a curable concrete mix on top of the formwork; curing the concrete mix; and placing reinforcement in at least one of the lowered parts of the formwork form, such that a reinforced beam is formed in said at least one lowered part of the formwork form. Such formwork is relatively lightweight and can provide certain physical building characteristics such as fire retardancy, thermal insulation and optionally acoustic insulation.