Building Upper Cabinet Boxes: Extending Your Kitchen Storage

You can maximize your kitchen’s storage space by building upper cabinet boxes that extend your existing cabinets to the ceiling. This eliminates dead space in your kitchen and increases the visual height of the room. Read about how to construct these figures in our step-by-step guide below, and watch the video above for a tutorial from House One’s Jenn Largesse. 

Planning Your Cabinet Box Project

Be sure to fully plan your cabinet project before you begin construction.  

Measuring and Designing

Consider the variables below while measuring your new cabinet sections: 

• Depth of existing cabinets, excluding face frames
• Height of the space between existing cabinets and the ceiling
• Width of cabinet boxes, excluding face frames and filler strips

Be sure to leave a small gap at the top to accommodate crown molding. 

In one This Old House project, the team deliberately left the space at the very top of the upper cabinets open rather than extending them fully to the ceiling. As explained during the build: “The space at the very top of the storage area is not terribly easy to reach. It’s not something that you can get at every day. And by leaving it open like this, it becomes kind of a display area. You can put interesting dishes or ceramics or whatever, right on top of this area. And you still have two shelves in here and plenty of storage space.” This is a smart alternative to filling every inch up to the ceiling — and it eliminates the need for crown molding altogether.

Selecting Materials

Gather the materials below before you start your construction project: 

• 3/4-inch plywood for the box construction
• 1×2, 1×3, and 1×6 boards for face frames
• Crown molding
• Pocket hole screws
• Wood glue and wood filler

Building the Cabinet Boxes

Once you’ve gathered your materials and put your plans in place, you can begin construction. Follow the steps below.

Cutting the Plywood

1. Rip a sheet of plywood so that it matches the depth of your existing cabinets.
2. Cut the plywood strips to create the top, bottom, sides, and back of each box.
3. Lay out the pieces and mark locations for pocket holes.

Assembling the Boxes

1. Drill pocket holes around the perimeter of the back wall and at the top and bottom of the side walls.
2. Use glue and pocket hole screws to attach the back to the bottom board.
3. Add the sides, and make sure all pocket holes face outward.
4. Cap the assembly with the top board.

If your cabinets have exposed ends, place the top and bottom between the sides to conceal pocket holes.

Pro Tip: When drilling pocket holes, make sure the wood grain of the piece receiving the screws runs perpendicular to the screw. As noted in This Old House Magazine, screws driven into end grain won’t hold. Also, adjust the drill torque so that the pocket-screw heads sit tight to the bottom of the pocket without stripping the hole, and always double-check the screw length — the screw tip should not exit the wood.

Creating Face Frames

Face frames give your cabinet boxes a finished look and provide a surface you can use to attach doors.

1. Cut 1×2 boards for the bottom rail and vertical stiles.
2. Use a 1×6 board for the top rail to create a nailer for crown molding.
3. Assemble the frame using glue and pocket hole screws.
4. Align the vertical stiles with those on existing cabinets.

Building the Frame: According to This Old House Magazine, start by drilling pocket holes at the end of each rail using a pocket-hole jig clamped even with one edge, then reset the jig along the other edge and repeat. Drill two pocket holes at each end of the upper and middle rails, and three at each end of the wider bottom rail. Apply wood glue to the ends of the rails and the adjoining edges of the mating stiles, clamp the frame together, then drive the screws into the edges of the stiles at each pocket hole.

Installing the Cabinet Boxes

Once you’ve completed your boxes and face frames, you can install the cabinet boxes in your kitchen.

Securing the Boxes

1. Position the boxes above your existing cabinets.
2. Screw through the back wall into wall studs.
3. Drive one or two screws through the bottom of the new box into the top of the existing cabinet for more stability.

Attaching Face Frames

1. Apply wood glue to the front edges of the cabinet box.
2. Position the face frame and nail it securely to the box.
3. Fill nail holes with wood filler, let them dry, and sand them smooth.

Finishing Touches on Upper Cabinet Box Installation

Complete your project with the finishing touches below.

• Add a corner shelf for additional storage or display space.
• Install crown molding to cover the gap between the new cabinets and the ceiling.
• Paint the new cabinets so that they match your existing cabinetry, or choose a new color scheme.

Pro Tip: Tom Silva, general contractor on This Old House, recommends filling the gap between cabinets and the ceiling with ripped-down filler pieces before tackling crown molding. For his approach, he rips fillers to size, fastens nailer blocks of two-by-four to the ceiling in line with the cabinet face, then uses wood glue and pins to hold the fillers in place. “I like to glue and nail the miter first and then install the facia as one piece,” Tom says — a technique that yields cleaner, tighter joints.

Additional Kitchen Upgrades

Consider some of the upgrades below, which can enhance your kitchen space:

• Add a new backsplash for a fresh, modern look.
• Build floating shelves in the pantry for additional storage options.
• Install new flooring to tie in the kitchen with the rest of your home.
• Remove pantry doors to create an open, accessible storage area.
• Update cabinet hardware.

Tools

Below are the tools and materials you need to complete this project.