Step 1: Measure and Plan

Clear out the room, measure and sketch out a plan for the space. For this project, Karl built a knee wall under the angled ceiling; the sofa will swing out from this wall. Determine the size of platform to hold the sofa and make sure it will have room to swing out fully.

Step 2: Frame the Knee Wall

Frame out the knee wall with 2" x 4" lumber. Start by nailing a long 2” x 4” across the angled ceiling joists to define the top of the knee wall. Attach a vertical 2” x 4” at each end of the wall and at the edges of the openings for the swing-out sofa and recessed bookcase. tach 2” x 4”s to the floor to complete the frames, avoiding the openings for the sofa and bookcase.

Step 3: Install OSB

Cut OSB sheeting to fit the newly framed knee wall, with openings to accommodate the sofa platform and bookcase. Attach to the frame with nails.

Step 4: Cut Lumber and Assemble Platform

Wearing safety glasses, cut birch plywood pieces to form the swing-out sofa platform.

Spread wood glue on the first joint in the platform, tack the pieces together with nails, then reinforce with screws. Repeat this process for all joints in the platform.

Tip: To keep the main piece of plywood from bowing, push and hold it in place while driving the nails.

Step 5: Finish as Desired

Sand, prime and paint the platform as desired. Attach plastic skidders — often used for moving large furniture

Step 6: Install the Platform

Attach the platform to the knee wall frame with two heavy-duty metal hinges. Make sure the platform is level and plumb, and that the platform fits properly in the opening when closed.

Step 7: Install Trim and Hardware

Install a handle or drawer pull on the outside of the platform to make it easier to swing out into the room. Use nails to attach wood trim around the platform opening.

Step 8: Hide the Gap

The swinging end of the sofa platform can't close up flush with the opening: If it did, the platform would crash into the wall every time someone tried to open or close it. So, Karl trimmed out and painted a strip of wood, added hinges and attached it to the edge of the opening. This mini-door opens to allow the sofa platform to swing out, but closed to cover the gap.