Consumer-perceived appearance tolerances in construction quality management

Purpose - To develop a method for measuring consumer-perceived tolerances concerning the appearance of unitised construction finishes (e.g. tiling, brickwork, paving, jointed façades). Design/methodology/approach - Consumer perceptions were converted into physical tolerances by drawing on an area of the behavioural sciences known as psychophysics. In particular, Weber's Law was used, which applies a formulaic approach to creating perception-based constants. A trial of this approach was undertaken on floor tiling in 50 residential properties. Tiling was chosen because it was considered representative of situations where the appearance of the finished work was important to consumer perceptions. In particular, consistency of tile joint width was measured, which had the advantage of tapping into tiles laid askew, in poor alignment or affected by variable tile sizes. Findings - Weber's Law offers an appropriate means of objectifying consumer perceptions into physically measurable tolerances. It was found that joint width in tiling can vary up to 70 per cent before consumers find the work beyond their threshold of acceptance - causing them to think the work "ugly". Saturation of such joints can occur up to three times per 5m2 area without causing consumers to complain. Practical implications - Such an approach can be easily applied to any unitised construction element where the regularity of appearance is important. Originality/value - The study provides a new and more balanced approach to the assessment of construction quality by ensuring THAT consumer expectations are taken into account, as well as the normal emphasis on technical quality standards.