As window systems and insulation have become more energy efficient, architects have increased the percentage of openings in exterior walls without sacrificing the thermal performance of the building. Because of this, it’s essential to understand what types of walls are permitted for a given wall configuration.
Wood shear walls with openings are permitted to be designed in a number of ways, with each method having its pros and cons. All wall types are limited to a maximum height to width ratio, otherwise known as the aspect ratio. The following information is based on a wall sheathed with wood panels rated for lateral resistance with blocking at panel edges.
Example
With a 10ft wall height, for a typical shear wall, the pier needs to be 2’-10” wide min, or 5ft wide to avoid a reduction in capacity. Using the force transfer around opening method (strapping above and below a window), smaller wall piers can be used since the height considered is just window height. Note that even with the force transfer around the opening method, wall piers must be at least 2ft wide.
