Professor Townsend From Cottage to High-rise: Prefabricated Building Components

4/5/13

Professor Townsend

In the 1830’s H. Manning decided to send his son, who was immigrating to Australia, off with a very special parting gift. Like any logical person would do, Manning decided to send his offspring away with a house. One that could be built in one location, disassembled into large pieces, packed into a hull of a ship, and re-assembled upon arrival at its final destination. From this concept, the idea of the prefabricated house was born [9].

Today, in addition to fully prefabricated, single family homes, commercial and high-rise buildings, full of prefabricated modules and components, saturate the market. Prefabrication has the potential to increase on-site productive during a construction project. Because, as the cliché goes, time is money, spending less time on site has the potential to positively impact a project’s bottom line. Through the use of technology, parties involved in the construction processes are pioneering and perfecting prefabricated and modular construction methods.

What is it?

Buildings are complex structures in which many systems come together to make a sturdy comfortable shelter. At a very basic level, they are made from a structural support system that contains walls that house complex electrical and ventilation systems. It is those systems and even full rooms that have the potential to be made in a controlled factory floor separate from the construction site.

The proliferation of Building Information Modeling (BIM) technology allows prefabrication to be used in areas it has never been used before. It allows users to virtually create a building to ensure that none of the building components intersect, or clash with, each other. McGraw-Hill Construction found that 78% of the parties using prefab and modular construction methods use BIM [2]. Digital coordination allows a contractor and its subcontractors to understand how prefabricated components must be laid out and constructed to that they can easily be tied into the building’s skeleton. The intimate understanding of how a building’s systems fit together, allows the building to be broken up into basic building blocks.

choose to build components of MEP systems in a controlled factory setting can often create them quicker and more efficiently than could be done on site.

There has always been a huge emphasis on productivity in the construction industry because, even if no work is happening on a construction site, money is being spent on the basic non-material items a contractor needs for construction or general conditions (GC’s). Because GC’s must be paid for throughout the project, the contractors are incentivized shorten project’s schedules. In a national survey of 809 industry professionals, of 66% firms using prefabrication and modular methods, 35% of them were able to decrease their project’s schedule by four or more weeks [2]. So, in order to truncate a project’s schedule, a general contractor may decide to prefabricate key items.