The framing of the Ferrari house looks different in many ways. First off most people notice the engineered studs that were used to build the walls, but the placement of the studs are also quite different from what is typically seen around here. The exterior walls of the home are a blend of advanced framing and staggered stud framing techniques.
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Advanced framing has been around for quite a while, and was originally developed as a Value Engineered frame design. The value was found in the reduction in the amount of material necessary to frame a home, less labor, and an increase in the insulating value of the walls by reducing the number of voids in the insulation. The basics of Advanced framing are all the framing members must be on 2′ centers and lined up with each other. For example the truss (or rafter), lands on top of the wall plate directly over the stud, which lands on top of the floor joist. This eliminates the need for a double top plate, since the roof load is transferred directly down on top of the framing members below. Headers are only used at locations that are carrying loads. Two stud corners (aka California corners) are used in place of triple studs at outside corners, and drywall clips are used to support the interior corners of the drywall. Ladder blocking is used where interior walls meet the exterior walls, instead of creating a 3 stud channel that is difficult to insulate. This framing approach requires a more careful layout of the framing to ensure that all load carrying framing members line up with the framing member below it.
The staggered stud framing strategy was employed into the design of the house by the Architect. For the exterior walls we have 2×8 top and bottom plates with 2×4 studs staggered every 1′ from one side of the plate to the other. The result is the exterior side of the wall has studs every 2′ and the interior side of the wall has studs every 2′. This framing technique is typically used create a “quiet wall” that minimizes noise transfer from one side to the other since the studs don’t touch both the interior and exterior wall surfaces, however, it does have other benefits. Staggering the studs creates a thermal break from the exterior side of the wall to the interior so that as the studs on the exterior side warm up in the sun, the heat isn’t transferred to the interior side of the wall since they don’t touch the drywall. It has also lent some flexibility in creating recesses in the walls at areas where traditionally a recess wouldn’t have been possible.
The staggered stud framing has probably cut down on the number of board feet of material required to frame the house as well. The 2×8 wall plates measure exactly 7 1/4″ wide, and each stud measures 3 1/2″ wide. Two studs together measure 7″ in width leaving us a 1/4″ shy of the wall plate width, so every 2′ of exterior wall we are saving 1/4″ x 8’10″(length of stud).
I was not fully sold on the staggered stud framing approach prior to the start of framing. My feeling was that it would add quite a bit of labor to the project, and wasn’t necessary since wood isn’t a good conductor of heat. Now, after using this method in the field, I can see why the architect chose it, and would definitely do it again should the opportunity arise.