Assessing the Time Productivity of Panelized and Modular Systems

Introduction

Modern Methods of Construction (MMC) are often considered an operative means to tackle housing shortages while stimulating economies, largely due to assertions that MMC can be more economically productive than traditional construction methods. While limited academic commentary on the theoretical advantages of MMC exists, arguing the degrees of their superior construction time-performance, the literature lacks empirical substantiation and comprehensive analysis of the time efficiencies of multiple MMC in a live house construction experiment, managed by one contractor on one construction site, and involving houses with identical or similar designs.

Methods

This research gap is partly fulfilled by presenting an evaluation of the construction time performance of six case studies from the first-of-its-kind house-building research experiment, including one traditional construction method and four MMC, involving one concrete panelized construction system, one steel panelized system, one timber modular system, and two identical steel modular construction systems. To improve the accuracy of the comparative analysis, the twelve most similar duplex houses, six of which were identical, were chosen from an initial sample of over thirty. The research method involves a literature review, analysis of the project programmes and residential building designs, and interviews with relevant construction personnel.

Results

The MMC houses generated greater construction time inefficiencies than those of the traditionally built houses. The planned time-performance of the panelized construction systems was inferior to that of some modular methods. Moreover, the time-performance of the two identical steel-based MMC was significantly different, which indicates that the time-performance does not depend solely on the use of a particular type of off-site manufacturing technique, but it can be influenced by the builder. Inadequate site management, logistics, and design issues were other main barriers to achieving the planned time efficiencies.

Conclusions

There is academic consensus that the design periods for MMC are longer than those of traditional construction methods. This study indicates that the MMC construction periods can also be longer. This is a significant finding because satisfying demands for new homes is dependent on the speed of the house production processes, and the literature agrees that MMC houses are more costly than traditionally built ones.