Development of an on-site Builder's estimating app for construction waste reduction

Nigeria generated over 40 million tonnes of waste between the years 2005 to 2010, while construction waste generated on construction sites accounts for 15% of that proportion. One of the actors of the alarming high rate of construction waste has been attributed to poor estimation of materials on construction sites. The aim of this research was to develop an on-site Builder's estimating application for construction waste reduction. The study utilized the use of a questionnaire instrument and the system design of an offline estimating app. The questionnaire was distributed to fifty (50) professional Builders on construction sites. The Builders were selected through a convenience sampling technique. The data collected was analyzed using SPSS v.21. Statistical tools such as frequencies, percentages, mean scores and Kruskal Wallis H test were used to present the data. The builder's offline estimating app was developed using the Java script language. The study revealed that poor estimation can result into high wastage of building materials, over/under ordering of building material and overall cost overrun. The result indicated that Builders mostly used manual methods for estimating the quantities of building materials. Required per time. The most used manual methods includes the use of drawing specification, manual calculation and inference i.e. knowledge from previous construction works. The study revealed that there is no statistical significant difference in the factors influencing the choice of building materials estimating technique utilized on construction projects. In conclusion, a Builder's estimating application was developed for the estimation of selected building materials on site in the required quantities. The study recommended that Builders should take advantage of the use of ICT in their construction activities. In addition, Builders should ensure that correct estimation of materials for construction works are done, as the inaccuracy in estimating building materials have dire consequences.