ZEMCH 2015 - International Conference Proceedings | Page 340

system? According to Yin (1994), case study should be usually adopted in researchers with “how”
or “why” questions; (2) the data collection happens in a “real world” situation. ¨Real world” conditions imply little or no control over the events during the design phase.
The product design was developed by a team of researchers2 from the Architecture and Civil Engineering areas of the State University of Londrina. The analysis of material waste and the components variety focused only on the components of wall panels: the studs, the sheathing (OSB), the
exterior finishing (cementitious board) and the interior finishing (gypsum board).
The percentage of material waste has been calculated as the long division of the material volume
not applied in the wall panel by the material volume applied. In turn, the material volume not
applied in the wall panel has been calculated as the subtraction of the material volume applied
in the wall panel from the material volume acquired. Besides the percentage of waste, the other
indicator evaluated was the variety of components formats; this indicator was simply the number
of variations of a component.
The tools for the data collection used in this research were: (a) manual of good practices for design and implementation of buildings in the LWF system (Details for conventional wood frame
construction - 2001; Canadian wood frame house construction - 2013; and Arauco - Ingeniería y
Construcción en Madera). These manuals were used to guide the decisions to reduce material
waste considering the best practices to ensure the adequate performance of the system (i.e., the
format of the boards in the openings areas of the panels); (b) design documents and architectural drawings, since the data to quantify waste were derived from it; (c) spreadsheet to record the
material consumption and waste resulting from the decisions taken by the team throughout the
product design development (Table 1); and (d) the researcher notebook in which the decisions
taken by the team and their justifications were recorded. These records were registered in order
to enable analysis of new decisions that were contrary to those already established.
Table 1 Protocol for the calculation of waste

Components

Entire
plates

Consumption
Total
Applied
Format
volume
volume
variations
(m³)
(m³)

Waste
Total
Entire
volume
plates
(m³)

Results
The case study was developed along the product design process of a social housing in LWF building system, by a multidisciplinary team. The author of this research focused on the on production process. The analysis purpose in this case study was to register and quantify the wall panels’
material waste, as a result of the product design. The analysis of this research enabled to identify
quantitatively the material waste, its causes and to suggest solutions to prevent them. The data
collected refer to the initials studies of product design, when were held six team meetings, before
the beginning of the executive design development. The case study tools for data collection registered the material consumption and waste for the decisions taken by the design team regarding
the wall panels’ modulation, in order to propose strategies for the reduction of material waste.
The product developed is a low-income dwelling in LWF building system that consists in a standard layout and three customization options for future expansions (Figure 4): (a) standard layout
(two bedrooms, living/ dining room, kitchen, bathroom and laundry ); (b) one room addition; (c)
one