McCraith House

The Butterfly House is one of the earliest examples in Australia to use prefabricated structural steel in a domestic building.[6] The structural core consists of two triangulated truss frames, bolted to large concrete footings at the inverted tip of the triangles. Steel 'C' section purlins and steel cross bracing form the base of the first floor, tying the triangulated truss frames together. The two dominant floor beams overlap the first floor truss supporting a series of timber floor joists that are cantilevered at each end forming the balcony and a portion of the living space floor. The 'Butterfly' roof is supported by a series of timber joists in a specific geometric configuration.[2]

The McCraith house is framed by a steel triangular structural system which represents the simplification of form that is a familiar aspect within the modernist architectural movement. Ornamentation is derived through the structural elements applied to the exterior, which contrast the classical approach to architectural embellishment. The house maintains the presentation of a modernist building whilst including the prominent architectural vernacular of the veranda.[2][4]

Elements from the McCraith house are found in the design of Iggulden House located in Beaumaris.[4] The most notable similarities between these two houses are cantilevers created by the projected horizontal lines and butterfly roof. Use of material contrast to emphasize change in program can be recognised in both buildings, where the timber beams of the veranda meet the glass threshold and pass through to the exposed stone walls. The post-and-beam structure is heavily pronounced in the exterior which is also seen in Richard Neutra's Miller House. The materiality of the McCraith House is also comparable to Richard Nuetra's "Miller House" through the use of glass and steel in its design to allow natural light to flow through the house. Both are rare examples of domestic steel construction from the mid twentieth century.[7]