A method for insulating the foundation of a building and an insulated foundation

The invention relates to a method for insulating the foundation of a building, where a load distribution layer is made on top of an insulating layer, both layers covering the intended floor area of the building substantially entirely. The formation of the insulating layer comprises the steps of: 1) laying a plurality of lamella elements made from mineral wool close to one another with the primary orientation of the mineral wool fibres being approximately vertical, and 2) providing one or more cover element(s) on top of the lamella elements to cover an upper surface thereof substantially entirely. The cover elements may also be made from mineral wool and stone wool is preferred both for the cover elements and the lamella elements. The load distribution layer is preferably made from concrete cast in-situ and a capillary barrier may be provided underneath the insulating layer.