Off-Site Construction of Apartment Buildings

The populations of major cities in Australia are increasing rapidly and facing an acute housing shortage. Traditional apartment procurement techniques involve lengthy lead times, and therefore, factory-based, or off site-constructed (OSC), multistory apartment buildings may offer the opportunity to help fulfill the need by significantly reducing build times and potentially offer good economic value. Other advantages of OSC may include superior quality, low weight ratios, economies of scale achieved through repetition of prefabricated units, use on infill sites, sustainable design standards, and better occupational health and safety. There are also positive labor and training implications, which may help to alleviate an industry wide shortage of skills through use of semiskilled labor. Previous uncertainties about the adoption of OSC because of the high capital costs and perception issues were generally based on precast concrete structures, which are a quite different building type in terms of flexibility, construction methodology, finishes, and delivery. Identification of drivers and constraints assists in the determination of current industry status allows for a benchmark to be established and future opportunities and directions for OSC to be determined. This paper, with the help of a case study of a residential building built recently in the central business district of Melbourne, will discuss the drivers and constraints of OSC and offer solutions to existing issues relative to the traditional construction development and procurement processes through OSC. (C) 2013 American Society of Civil Engineers.