This study is important in terms of applying organisational buying behaviour theory to structural material choice processes in the Irish residential construction sector, at a time when as the construction industry is awakening to the benefits and necessity of marketing. Structural material choice processes are explored within a framework developed from the organisational buying behaviour literature including seminal such Robinson, Ferris and Wind (1967), Webster and Wind (1972) and Sheth (1973). The framework proposes three material choice process stages and three levels of participation. The three stages, which are not entirely sequential, are:- structural material selection, structural timber specification and structural timber supplier selection. Each of these stages is envisioned as comprising an unspecified number of related decisions. Participation in each of these stages is explored through the three participation levels:- decider, involvement, and influencer. Structural material choice criteria and structural material related changes are also explored. A study model is presented, which is firmly rooted in the study framework and emerged in its working format during the interview analysis. The mixed-method approach adopted commenced with a dominant interview phase, which explored structural material choice processes on a development specific basis. A range of developments and development organisations were targeted and interviews were conducted with both developers and designers in each of the five subject developments. The less-dominant mail survey phase of the primary research aims to extend the investigation of structural material choice processes in the speculative residential development sector. This survey offered, amongst other things, the opportunity to provide participation level and criteria ranking in the three study generated stages of structural material choice processes. The study provides insight into material choice processes at a time when organisational buying theory is experiencing a significant shift towards relationship based theory. The findings find little evidence of strong development organisation / material supplier relationships to date, however future scope for strategic relationships is highlighted in the move toward new development systems, such as timber frame construction.