All wall elevations are set forth in your home’s architectural blueprints. It's tempting to ask your contractor to alter the plans and raise the ceiling in one or more areas of the house, but alterations of this nature are usually very costly because adjoining walls, second-story floors, attic configurations and even plumbing that runs through walls may have to be changed. If you want custom wall heights in certain parts of your home, it's best to work directly with an architect to draw custom plans that suit your needs.
If you’re doing your own wall framing, it won’t be long before you discover that wall studs are not of the same dimensions as they are labeled in the lumberyard. An 8-foot wall stud is not 96 inches long but 92 and 5/8 inches long. A standard 9-foot stud is only 104 and 5/8 inches long. You'll get back more than the missing 3 and 3/8 inches when you install the studs between one floor plate and two top plates, which adds 4 1/2 inches. Now the wall height is a little on the high side, but this enables you to install drywall on the ceiling and lay flooring, which eventually gives you a finished wall height very close to the 8- or 9-foot standard.
Required wood dimensions change as wall height increases. The 2-by-4 studs that are acceptable for framing an 8- or 9-foot wall are too flimsy to frame a 16-foot entry wall. Local building codes regulate lumber dimensions to ensure stability, but when framing taller walls, you need larger dimensional lumber such as 2-by-6's, 2-by-8's or even 2-by-12's to support the higher structure.
Horizontal blocking consists of cutting and installing studs of the same dimensions as those of the wall studs between two vertical studs. Horizontal blocking helps stiffen tall or flimsy walls. It may also be a requirement in tall walls to decrease the rapid spread of fire in a wall cavity. Architectural blueprints and local building codes determine where and how much horizontal blocking you should install.