Preface

Housing is a system of energy and environment. The needs and demands are dynamic, having been changed in the course of time. The shifts in sociodemographics highlight the emergence of non-traditional households and influence housing configurations and performances. With regards to the history of housing, prefabrication can be considered as an invention of 19th-century industrialization. It realizes off-site construction of houses where entire units, or the parts and components, are fabricated in a factory and transported to the building site where the homes are erected. Such industrialized housing delivery can be performed rapidly with a minimum of labor efforts and under any conditions of weather and season. The dwellings built through the process are called "prefabricated homes" or "prefabs." These terms were already recognized in the 1930s, albeit the milestone dates back to the 1930s when the first historically documented prefabricated homes were publicized in Great Britain. Broadly, the advantages of prefabs are said to be the lower and more predictable cost, better and more standardized quality, and faster and more punctual construction, when compared with conventional homes. In fact, during the construction, site-built homes can be rained on, with uncovered lumber, plywood, insulation, and other susceptible materials being soaked or blown around during bad weather. Such on-site nuisances naturally degrade the quality of site-built housing. Moreover, site-debris piles from packaging, wrapping paper, and material scraps provide builders and their insurers with additional worries due to potential liability in relation to unexpected injury of workers and neighbors. Damage or loss of building materials from malicious acts is inherent in site-built construction. Accordingly, constructing prefabs tends to alleviate or eliminate these on-site nuisances that somewhat affect product and construction quality. Also, it helps reduce building costs and time through product and process standardization, which is a prerequisite to prefabrication.

Global warming accelerated by excessive carbon dioxide (CO2) emissions is becoming conspicuous. Generally, a house consumes a significant amount of energy before and after occupancy, and the associated CO2 emissions are partially contributing to climate change. Towards securing environmental sustainability, housing needs to be net carbon neutral (or *zero energy*) in consideration of CO2 emissions derived from the overall energy use. Nearly 40% of global energy use derives from construction, which generates significant impacts on how to meet the market needs and demands for social, economic, environmental, and human sustainability of built environments and beyond in developed and developing countries. In consideration of these dimensions of sustainable development in the built environment, the notion of *zero energy mass custom home* (ZEMCH) was envisaged and discussed globally. Towards the ZEMCH delivery, a *mass customization* concept was scrutinized initially. It emerged in 1987, the same year as the general notion of *sustainable development* became widespread.

This book is an initial attempt to integrate the two notions of *sustainability* and *mass customization* by reviewing the potential positive capacities of *prefabricated construction* with the aim to facilitate the future delivery of ZEMCHs that meet the wants and needs of individuals as well as society in the global context.

> **Masa Noguchi** ZEMCH EXD Lab, Faculty of Architecture, Building and Planning, University of Melbourne, Melbourne, Australia

Section 1
