Introduction
The material waste has been recognized as a major problem in the construction industry and has important implications for industry efficiency and environmental impact of projects ( Formoso 2002 ). However , the early stages of product development process have been failing in defining product solutions that meet the rationalisation of production aimed at avoiding waste of high-value materials and low productivity of manpower . This gap is more harmful to the social housing projects where the reduction of costs and time is significantly important . There are two variations of the industrialized construction system approached in this research : Light Wood Frame ( LWF ) or Light Steel Frame ( LSF ). Both of them prove to be an alternative technology with potential for the rationalisation of the construction process , especially for low-income housing projects . The main benefits to the production process are : ( 1 ) the possibility of a significant reduction in the lead time , which is an important issue in social housing ; ( 2 ) the opportunity to simplify the tasks carried out in the construction site ; and ( 3 ) the reduction of material waste if the design takes account of the components ’ connections ; and ( 4 ) the insertion of the pipe building facilities ( electrical , water and sewage ) in the empty space between two wood structural panels ( OSB - Oriented Strand Board ). This last benefit has implications also in the elimination of the interdependence between production tasks and the reduction of waste , since it eliminates the need to demolish walls for the insertion of building facilities and for the maintenance in the use phase . In this research , LWF is the construction system studied . Its main characteristic is the wall ’ s configuration which is composed of a continuous sheathing made of wood structural panels ( OSB - Oriented Strand Board ) nailed on a light wood frame . The exterior and internal finishes are attached on the OSB . This system is suitable for the construction of buildings up to five floors ( LPBRASIL 2011 ). Both construction systems , the light steel frame and light wood frame , can be performed using three construction methods : stick , panels or modular ( Freitas and Crasto 2012 ). In the stick method , all stages of production are carried out on site , since the assembly of framing until the sheathing with the wood structural panel , finishing , and the passage of installations . In the panels ’ method , the production of walls , slabs and roofs is performed at the factory and assembled on the construction site . The use of this method increases the dimensional precision and reduces the tasks carried out on the site , allowing a higher production speed . The modular method corresponds to units completely pre-manufactured that are delivered on site with all the finishes , insulations , windows , bathroom components ( toilet , sink , and shower ) and piping . The possibility of rationalisation , especially the reduction of lead time , increases as the steps of the production process are transferred from site to the factory . These industrialized construction systems enable the designers to achieve minimum levels of material waste . However , the effective rationalisation depends on the quality of design and planning , which should ensure the best utilization of high-value materials . A wide variety of components may impair the rationalisation of the construction process . Thus , there should be a concern in the definition of the wall panels to reduce the material waste ( OSB and finishing boards ), in addition to maintaining a low variation of panels to be produced in the factory . This aspect should be intensively considered in mass production . It was not possible to find scientific papers discussing design solutions for reducing material waste of panels . Therefore , the aim of the present study is to present design solutions for reducing material waste of the wall panels . The study was carried out during the development of the product design . The data of material waste and its causes allowed the analysis of the design
334 ZEMCH 2015 | International Conference | Bari - Lecce , Italy