A Comparative Study of the Design Process in General Construction Companies and Design Firms in Japan

Abstract

This paper aims to illustrate the design review process of ″General Construction Companies″ (GCCs) and ″Design Firms″ (DFs) in Japan. It then quantitatively evaluates the time duration for the production of ″design and supportive documents″ which is required to go through a design review.
The research is divided into three stages. First, the constraints in the design process in both GCCs and DFs are illustrated. Second, the duration of each design phase is measured to assess the allocation of resources for design coordination required by the constraints. Third, the most commonly shared building types in the survey were evaluated based on the ″designed floor area per month.″
The survey statistically confirms the characteristics of the front-loaded design process by GCCs in the Preliminary Design phase to the Detailed Design Phase. GCCs have more cost and time constraints than DFs, through the involvement of the Cost Estimation and Procurement division in the construction department. It requires the production of ″design and supportive documents″ throughout the design process. On the contrary, DFs tend to spend more time and resources in the later part of the design process. This grants DFs more flexibility in cost and time throughout the design process as they have less strict constraints than GCCs.