Kitchen Cabinet Sink Base, 36"

Build the base as shown, 1/2" narrower in width than the cabinet carcass to account for the face-frame overhang. Drill pocket holes now for attaching the base to the underside of the cabinet in a later step, then set the base aside.

Rip the plywood sheet to a 22-3/4" strip and build the sides and top into the carcase. Drill 3/4" pocket holes along the front edges for attaching the face frame in a later step.

Attach the back supports at the top and back of the carcase — scrap plywood strips or 1x3/1x4 boards both work. With no back panel on a sink base, these supports are what keeps the box square.

Build the face frame as its own flat assembly: clamp and mark each joint before gluing, and build with 3/4" pocket holes and 1-1/4" pocket hole screws. Use fine-thread pocket hole screws if the frame is hardwood, especially where hinges will attach.

Add scrap plywood or 1x3/1x4 corner support pieces where the countertop will land — these give the top plywood something to fasten to once the cabinet run is assembled, and add corner support that helps keep the cabinets square.

Once the carcase is built, attach the base, flush to the back and sides.

Attach the completed face frame to the front of the carcase with glue and pocket hole screws through the pre-drilled front edges.

Sand every exposed surface and finish. Doors and the drawer face are their own project — build or order them separately and hang once finished.