Drilling through the cost barrier of high performance buildings - Part 3: Prefab Building Components
Excerpts taken from Terrell Wong at Green Building Festival in Toronto, October 2019 https://www.youtube.com/watch?v=VXSpcyUgCKM
As the construction industry advances, larger prefabricated components are designed and built. What once sounded like a wild idea, is becoming the norm slowly.
Entire bathrooms come in “pods” complete with their walls, floor, fixtures and finishes. These “pods” can either be shipped directly to site or to another factory where it can be built into an entire prefabricated suite, and then to the site for installation. Not only bathrooms, kitchens are available prefabricated, with appliances, counters and a backsplash all installed in a day. Prefabricated building components help to cut down on costs of new buildings by making the construction process faster, easier and safer.
Prefabrication at a large scale is possible and already underway in New York.
Marriott is constructing its latest hotel in New York using modules that have been prefabricated in Poland. The base of the building was constructed on site while the suites and some of the communal spaces have been prefabbed in the factory. Finishes including furnishing, linens and even toiletries are being included in the prefab suite at the factory. The exterior of the building is also included so that once the unit is installed minimal work needs to be done. It is estimated that one floor will be installed by crane a day. This decreases overall construction time by approximately 6 months for a comparable sized building. The cost of construction will be reduced by 30% even with transportation costs of prefabricated components. On site labour will be reduced by approximately 70%, and this isn’t the only building of its kind.
Hickory Group, an Australian based construction firm uses prefab modules that include the exterior façade. Bathrooms are fully finished and structure is integrated to create mid to high rise buildings. Each pod is installed in less than an hour resulting in a construction time savings in the range of 30%. There is a minimal need for safety railings and equipment for construction workers since the building is already fully enclosed which reduces costs and labour time.
Material costs are less flexible, you still need the same amount of sticks and bricks to build the structure, however on large scale projects there is potential for small percentages of savings. In the overall budget of a project this is minimal. Savings can be gained from better design and use of materials. When construction is done in a factory setting, the ability to use similar materials over many projects allows companies to source raw materials for a lower price. Lastly, time savings from avoiding bad weather, delays, and mistakes on these projects can have a significant reduction in the cost of construction.
Sources: