Abstract: The invention relates to a dome-type structure constructed from four basic triangular structural units. Each basic unit is an isosceles triangle which has predetermined angular edges. The four units are interrelated in their dimensional sizes and angular edges. The several units are installed in four circular tiers whereby abutting adjacent units fit together properly, and whereby upper tiers are canted inwardly to enclose the structure. The structure requires no internal support members. The radius of the circular base is greater than the height of the structure.