Impact of Change Orders on Construction Material Waste in Residential Buildings Projects

The current study attempts to address the relationship between material waste and change orders in residential building projects implemented in the West Bank in Palestine. The main objectives include: (1) identify the main factors affecting change orders in residential projects, (2) identify the main factors affecting martial waste eon construction sites, (3) address the relationship between change orders and construction material waste, (4) develop prediction model that shows the impact of change orders on material waste. To achieve this, two methods are used: (1) questionnaire survey is conducted to identify the main factors affecting change orders and the major factors of material waste on construction sites. Fourteen (14) factors believed to affect change orders and 15 factors that might affect material waste are investigated in this study. (2) Case study is conducted to address the impact of change orders on material waste. Data collected from 40 residential building projects implemented in the West Bank in Palestine. Regression analysis is used to establish the predictive model that relates the change orders and material waste. Results indicate that the top five factors affecting change orders include: change of project scope by owner, shortage in equipment and materials, change in materials, design mistakes, and change of plans by owner. It also shows that the top five factors affecting material waste are: rework, lack of labors skills, design errors, purchasing materials not complying with specifications, and frequent design changes. The results revealed a strong relationship between number of change orders and construction material waste on site.