Comparison of Different Roof Types in Housing Projects in Turkey: Cost Analysis

Abstract

As essential elements of buildings, roofs traditionally correspond to about 3-8% of total project cost. Despite this considerable share, in the literature there have been only a few researches that investigate roof types preferred by owners/designers and make a cost analysis to reveal cost differences between alternatives. Toward this aim, in this study, twelve types of roofs installed in construction projects in Turkey were first examined. In this context, practical answers of the following questions were investigated briefly: (i) how different are roof types from each other, (ii) by which criteria are roofs chosen, and (iii) which roof types are selected in which buildings (such as, housing and industrial). Among twelve roof types, reinforced concrete flat roofs (RCFR) and free standing wooden roofs (FSWR) were determined as the most used roofs in housing projects. Finally, a real- life building project was considered. Its roof plan and cross sections of above-mentioned two roofs were given, and their detailed measurements and cost estimations were made. As a result, in terms of initial investment cost, a RCFR which has similar insulation conditions with a FSWR was found to be 35.46% more inexpensive than a FSWR. In conclusion, designers/constructers can manage projects more efficiently by directing their clients towards a more inexpensive option. Thus, potential building owners can allocate lower project budgets by decreasing their roof costs. As a research implication, future studies can compare life cycle costs of these roofs, which will likely provide a broader perspective for better cost management practices.