Utilizing pre-fabricated wall panels in building construction is still used in less than half of new construction it is a concept that is growing in popularity. The concept of pre-fabrication is not new; the market has increased to over 15 percent of homes built in recent years.
Pre-fabricated wall panels are similar to on site framing following the same principles for stud spacing, headers and window and door frames. But the panels are constructed in a factory and shipped to the job site. Once on the site, they are typically lowered in place by crane and secured by site workers. Unlike manufactured housing, pre-fabricated panels must meet building code requirements.
Exterior walls as well as interior load bearing and non-load bearing walls can be constructed as panels in the factory. There are distinct advantages to purchasing pre-fabricated panels.
1- Precision and Customized Design
Most panel manufacturers use sophisticated software to design panels for a project. Building plan specs are input into the computer program and the engineer designs the panels off of the building plans. Because the wall panels must comply with local building codes, the program takes codes into account. The program also calculates building load transfer requirements and stress levels.
Though straight walls are most common, most manufactures can customize panels for angled walls, bay window designs, etc. For exterior walls, attaching sheathing or wall insulation at the factory may be an option. Others may prefer pre-fabricated naked stud walls.
2- Factory Construction
Factories are not subject to delays due to rain, snow or other weather. Workers construct the panels under optimal conditions and are using aided by automated machinery and laser measurements. According to American General Construction Inc., the results are often more precise and accurately measured panels that should fit together on site without problems.
3- Reduced Time and Labor Costs
With the use of a crane, exterior wall panels can often be installed in a day per floor. Each panel may only take minutes to secure once guided in place. Because less time is used to secure the wall panels, less man hours are spent on framing carpenters.
In addition, the speed at which the walls are erected may also save time on other building professionals such as drywall contractors, plumbers and electricians. They can begin work as soon as the wall panels are in place with less idle time or down time. A National Association of Home Builders study estimates that on a 2,600 square foot home, up to 66 hours of labor can be saved with pre-fab panels.
A little advanced planning can speed up the overall construction time. Most panel manufactures can have a finished product delivered from 2 weeks to 8 weeks. If the manufacturer begins work at the time the foundation is dug, the panels may be ready for delivery by the time the concrete had cured and the first floor is laid.
4- Less Waste
Because the panels are constructed off site, there is little or no lumber cutting necessary on site. The lack of cutting not only saves time, the lack of scrap lumber keeps the job site cleaner and safer.
In addition, dimensional lumber and plywood on a construction site can be an invitation for theft of materials. If a theft occurs, additional costs in the form of repurchase and additional delay due to redelivery will add to the overall building cost. Because panels are far too large to steal and are erected on the day of delivery, the risk of theft is avoided.
The overall cost of pre-fabricated panels versus onsite stick construction varies greatly depending on the building plans, the amount of customization, access to the job site and the distance from the factory to the job. These factors can only be answered through discussions with the factory rep, the general contractor and framing contractor. But for quality control and time savings, it is an option to inquire for the building owner.
