Walls having cavities in, but not between, the elements, i.e. each cavity being enclosed by at least four sides forming part of one single element using elements having specially-designed means for stabilising the position by interlocking of projections or inserts with indentations, e.g. of tongues, grooves, dovetails
Walls having cavities in, but not between, the elements, i.e. each cavity being enclosed by at least four sides forming part of one single element using elements having specially-designed means for stabilising the position by interlocking of projections or inserts with indentations, e.g. of tongues, grooves, dovetails