This project is all about a couple looking for a separation -- a separation of spaces, that is. They would like to visually divide their living room from an adjoining den without erecting walls. The idea is to clearly define the adjacent spaces while keeping them connected and related to each other. They accomplish this with a half-wall and columns.
Construct a simple plywood mock-up to help visualize the dimensions for the knee wall dividers and columns. View the mock-up from both rooms to gain different perspectives and ensure that it is sized appropriately.
Cut two-by-fours to dimension for the internal structural wall frame for the knee wall dividers. Each knee wall will require two long side pieces and shorter lengths for the top and bottom.
Lap the top and bottom framing components for the knee wall divider over the ends of the long sides and secure them with screws. Working on a flat surface such as the floor will keep them from skewing during assembly.
Nail one-by-four strips to the assembled knee wall frames to add additional thickness to match the existing doorway opening when sheetrock is added. Attach the frames to the existing doorway and floor with screws.
Make four wide drywall panels and two narrow end panels. Score the drywall's paper face, break it along the score-line, and cut the paper back to separate it. Secure panels to the knee wall divider frames with screws.
Attach metal corner strips to protect the fragile edges of the knee wall divider and provide sharp, clean corners. Nail them in place with a hammer, working carefully to avoid hitting and denting the metal bead.
Smooth joint compound and paper joint tape over seams in the knee wall dividers. Add a layer of joint compound over the tape and over the metal corner beads. Let dry and apply an additional coat. Sand the dried surface.
Cut and notch a solid poplar top for the knee wall dividers, sizing it to overhang on the free edges. Route the poplar edges to round them and leave smooth crisp corners. Secure the tops with nails.
Use a variety of decorative wooden millwork to trim the wall frame and the exposed edges of the original wall and lift the wall from ordinary to elegant. Miter the corners for a professional look.
Shorten the purchased columns as necessary to fit with their decorative details in the opening on the knee wall dividers. Glue and nail the capital, base, and shaft to assemble the columns and secure them in position. Paint as desired.