The Australian Concrete Standard (AS3600-2009) includes updated guidelines for the simplified design of axially loaded walls. More specifically effective length factors have been introduced to distinguish between walls supported on two, three and four sides. There is very limited information on the behaviour of walls supported on three sides. As such this paper presents results from an experimental study on six half-scale reinforced concrete walls supported on three sides with various opening configurations. All panels, with a slenderness ratio of 30, were subjected to a uniformly distributed axial load at an eccentricity of tw/6. Crack pattern behaviour and effects on ultimate strengths are discussed. Comparisons are made with identically sized wall panels supported on two, three or four sides (with and without openings) from other studies.