Transform Your Space: The Ultimate IKEA Billy Bookcase Built-In Hack with Glass Doors

Are you dreaming of elegant, custom-built bookshelves that look like they cost a fortune, but without breaking the bank? Look no further! This comprehensive guide will walk you through creating stunning DIY built-in bookshelves with glass-front Oxberg doors, using the incredibly versatile and budget-friendly IKEA Billy bookcases.

Our journey with the IKEA BILLY bookcase hack is extensive. Having completed several iterations, including a recent installation in our home office makeover, we’ve refined the process to an art. Each project has presented unique challenges, from varying Billy bookcase sizes to navigating IKEA’s occasional stock shortages. This particular tutorial focuses on a specific “skinny” version with glass panel doors, providing adaptable steps to suit different availabilities and wall dimensions.

If you’ve previously explored our DIY built-in entertainment center using tall, wide Billy bookcases or our DIY playroom built-in bookshelves using short, wide Billy bookcases, you’ll recognize some core principles. While the underlying steps are largely consistent, this method, incorporating strategic trim work and custom door hanging, is what we consider our definitive technique for achieving truly integrated, high-end built-in bookshelves.

Why IKEA Built-In Shelves Are the Best Solution for DIYers

Built-in shelving units are a timeless design feature that effortlessly elevate any room. Whether it’s a living room, home office, playroom, media room, or dining area, built-ins add sophistication, character, and invaluable storage. The beauty of this DIY project lies in transforming standard, affordable IKEA units into custom masterpieces that appear seamlessly integrated into your home’s architecture.

Unlike building custom cabinetry from scratch, which requires advanced carpentry skills and significant expense, the IKEA Billy bookcase hack offers a fantastic shortcut. A large portion of the work, the fundamental structure of the bookcases, is already prefabricated for you. This dramatically reduces complexity, time, and overall cost, making a high-end look accessible to DIYers of all skill levels.

Beyond aesthetics, these built-ins provide exceptional vertical storage, maximizing every inch of wall space without the bulkiness of freestanding units. They are perfect for decluttering, showcasing decorative items, and organizing books or supplies. If you’re seeking a cost-effective way to achieve a custom, high-end aesthetic, need abundant vertical storage, or simply want to dive into a rewarding beginner-level carpentry project, this detailed tutorial is your ultimate guide.

How to Make Built-In Bookcases Using the IKEA Billy Hack

Essential Tools

Having the right tools is crucial for a smooth and successful DIY project. Here’s what you’ll need to create your custom built-in bookshelves:

• Circular saw or table saw: For precise, straight cuts on larger boards.
• Coping saw or jigsaw: For intricate cuts, especially when fitting trim around existing moldings.
• Saw horses: To safely support your workpieces during cutting.
• Power drill and bits: For drilling pilot holes and driving screws.
• Orbital sander and medium to fine grit sanding pads: For smoothing surfaces and filler.
• Cordless brad nail gun: For quickly and securely attaching trim pieces with minimal visible fasteners.
• Hammer: For general use, and specifically a claw hammer for baseboard removal.
• Pry bar: Essential for carefully removing baseboards without damaging walls.
• Tape measure: For accurate measurements throughout the project.
• Step ladder: To reach higher sections of the bookcases and walls.
• Clamps: To hold bookcases securely together while joining them.
• Combination square: For marking precise lines and depths.
• Utility knife: For cutting caulk lines and other precise tasks.

Materials You’ll Need

The following list details the materials used in this specific project. Remember to adjust the number of Billy bookcases and Oxberg doors based on your wall’s dimensions and desired layout. Always measure your space carefully before purchasing to ensure you have enough materials.

• 8 – 15 3/4″ x 93 1/4″ Billy bookcases (or size appropriate for your space)
• 4 – long Oxberg panel/glass cabinet doors (for concealed storage)
• 4 – short Oxberg panel/glass cabinet doors (for additional concealed storage)
• #8 1 1/2″ Wood screws: For joining bookcases and attaching framing.
• Bookcase anchors (typically included with IKEA bookshelves): For securing units to the wall for safety.
• 5 – 2x4x8 pine boards: For creating a sturdy frame and filling larger gaps.
• 2 – pre-primed 1x10x8 boards: For side panels or deeper trim.
• 4 – pre-primed 1x4x8 boards: For base and crown molding trim.
• Finishing nails: Used with the brad nailer for trim.
• Caulk: For filling small gaps and creating a seamless finish.
• Wood filler: For patching nail holes and minor imperfections.
• Loctite foam (or similar expanding foam): For larger, irregular gaps.
• Painters tape: For marking and protecting surfaces during painting.
• Satin finish paint: We recommend matching the IKEA white color for a cohesive look. Bring a small detachable shelf board to your paint store for an accurate match.
• Optional: Shellac-based primer and urethane alkyd enamel paint for a custom paint job over the entire unit.

Important Notes on Measurements: Carefully consider your wall’s length and ceiling height. Our wall was 11.5 feet wide with 8-foot ceilings. The bookcases, including height extenders, reached approximately 7.5 feet, leaving about 6 inches for the top trim board. If your space has carpeting, it’s advisable to remove the section directly beneath where the bookcases will sit for a truly built-in appearance.

Step-by-Step Guide to Building Your IKEA Billy Bookshelves

Step 1: Prepare Your Wall by Removing Baseboard

For your built-in bookshelves to sit flush against the wall and achieve that custom, integrated look, you’ll need to remove the existing baseboard and any shoe molding trim. Begin by using a utility knife to carefully cut along the caulk lines where the baseboard meets the wall and the floor. This prevents peeling paint or damaging the drywall. Next, using a claw hammer and a small pry bar, gently work the baseboard away from the wall. Start at one end and slowly move along, prying carefully to minimize wall damage.

Step 2: Assemble the Billy Bookcases

Now, it’s time to assemble your IKEA Billy bookcases according to the manufacturer’s instructions. Crucially, assemble all the main box structures, including any height extenders you plan to use for taller units. However, for a true built-in appearance, *do not* attach the thin cardboard backing that typically comes with the bookcases. Your wall will serve as the natural, solid backing for the built-ins. You can also temporarily leave off the height extenders at this stage, reattaching them after anchoring the main bookcase units to the wall for easier access during installation.

Step 3: Eliminate the Back Gap for a Seamless Look

Since Billy bookcases are designed to accommodate a thin backing, omitting it will leave a small, unsightly gap at the back edge of the bottom shelf. To achieve a perfectly seamless built-in appearance, you’ll need to address this. Measure the depth of this gap and cut a piece of 1×2 board to match the length of the bookcase. Using a finish nailer, attach this 1×2 board to the back edge of the bottom of the bookcase. This effectively closes the gap, creating a flush surface against your wall. Any minor cracks that remain can be easily filled with caulk later for a flawless finish.

Step 4: Securely Anchor the Bookcases to the Wall

Safety and stability are paramount for your built-in unit. Before permanently fixing anything, carefully measure your wall to ensure the bookcases are perfectly centered and positioned as desired. Use a stud finder to locate the wall studs. It is critical to anchor the bookcases directly into these studs for maximum security. Start by anchoring the middle bookcase firmly into a stud using the provided IKEA anchors or robust wood screws if possible. This central anchor will provide a strong starting point for the rest of your installation.

Step 5: Join the Billy Bookcases Together

Once your bookcases are properly positioned and anchored to the wall, the next step is to join them to each other to form a cohesive unit. Use sturdy clamps to tightly hold the side panels of two adjacent bookcases together. Ensure they are perfectly aligned both vertically and horizontally. With the bookcases held firmly in place, use your power drill to drive wood screws through both side panels, securing them to one another. Repeat this process for all adjacent bookcases. This step is crucial for the overall structural integrity of your built-in unit. Later, the added trim boards will further reinforce these connections, creating an incredibly strong and stable piece of furniture.

Step 6: Prepare to Conceal Gaps with Trim Work

Now that your bookcases are assembled and secured, you’ll likely notice small gaps along the sides and top where the units meet the wall and ceiling. These gaps are exactly what we’re going to transform with strategic trim work, making the entire assembly appear as if it was custom-built into your home’s architecture, rather than an off-the-shelf IKEA solution. This step is about envisioning the finished, seamless look and preparing the framework for it.

Step 7: Install 2x4s for Structural Support and Gap Filling

To provide a robust backing for your decorative trim and effectively bridge any larger gaps between the bookcases and the wall, you’ll install 2×4 boards. Measure the small spaces along the sides of the outermost Billy bookcases where they meet the wall. Cut 2x4s to fit these sections. Using your drill, secure these 2x4s both to the wall studs (where possible) and directly into the side panels of the Billy bookcases. This creates a solid anchor for the side trim. Repeat this process for the top of the shelving unit, installing 2x4s to bridge the gap between the top of the bookcases and the ceiling. These 2x4s serve as essential furring strips, ensuring your subsequent trim work sits flush and has a solid surface to attach to.

The same technique applies to the upper sections. Attaching 2×4 boards to the top of the shelving unit not only helps close the gap below the ceiling but also provides a strong base for installing crown molding or any upper trim, ensuring a solid, custom-finished look.

Step 8: Install Base and Crown Trim with 1×4 Boards

This step is crucial for making the entire unit look like a single, cohesive piece of built-in cabinetry. Take your pre-primed 1×4 boards and attach them to the very bottom front of the bookcases using your brad nailer. To ensure a professional finish, you’ll need to “cope” the ends of these boards to seamlessly meet any existing baseboard on the adjacent walls. Use a coping saw or jigsaw to carefully cut the profile of your baseboard into the 1×4 trim. Don’t worry if your cuts aren’t absolutely perfect; caulk can work wonders later to hide minor imperfections. Repeat this same process for the top of the Billy bookcases, coping the sides of the 1×4 boards to fit flush against your existing crown molding or to create a new crown detail. This trim will instantly transform the appearance, making the individual IKEA units disappear into a custom design.

Step 9: Add Finished Side Panels with 1×10 Boards

The sides of your outermost bookcases will likely reveal the unfinished edges or a slight gap between the unit and the wall. To achieve a perfectly polished, built-in look, you’ll need to create finished side panels. Measure the precise gap between the bookcase and the adjacent wall. Using a circular saw or table saw, cut a 1×10 board (or a suitable width board) down to fit this measurement perfectly. This trimmed board will serve as a continuous, custom face panel along the side of the bookcase, concealing any gaps and providing a clean, architectural finish. Attach this board using your brad nailer.

Step 10: Unify the Front with Vertical 1×2 Trim

Now that the base, top, and side panels are in place, you’ll likely notice subtle seams where the individual Billy bookcases meet vertically. To truly transform them into a single, custom unit, you need to conceal these junctions. Using your finish nailer, attach 1×2 boards vertically to the fronts of the bookcases, precisely covering the cracks where the individual units meet. These vertical trim pieces act as stiles, giving the appearance of custom-built cabinetry and providing a robust, unified facade. This step is where the illusion of custom-built quality really starts to take shape.

At this point, your project should be looking incredibly flush and solid! The various trim pieces have integrated the separate bookcases into a unified structure. The next crucial steps involve filling any remaining cracks and gaps, as well as covering nail holes, to prepare for a pristine paint finish.

Step 11: Meticulously Fill Gaps, Cracks, and Nail Holes

A flawless paint finish relies heavily on meticulous prep work. Start by addressing any larger gaps with Loctite foam (or a similar expanding foam). For instance, if there’s a slightly wider gap between your bottom 1×4 trim and the bookcase base that’s too substantial for caulk, foam is the ideal solution. Once the foam is fully dry and expanded, carefully trim any excess with a utility knife and sand it smooth to match the surrounding surfaces.

Next, use caulk to fill all smaller cracks and seams where the newly installed boards meet the wall or each other. Apply a thin, even bead and smooth it with a wet finger or caulking tool for a clean line. Finally, use wood filler to cover every single nail hole from your brad nailer, as well as any minor imperfections or small cracks in the wood itself. Apply the filler, let it dry completely according to manufacturer instructions, and prepare for sanding.

Step 12: Sand All Surfaces Smooth

With all your fillers and caulk thoroughly dry, it’s time to achieve a perfectly smooth surface for painting. Use an orbital sander with medium to fine-grit sanding pads to smooth out all areas where you applied wood filler, trimmed foam, or where any wood edges feel rough. Pay special attention to the trim pieces to ensure a professional, uniform texture. This sanding step is critical for the paint to adhere properly and for the finished product to feel truly custom-made.

Step 13: Thoroughly Clean and Remove Dust

Before applying any paint, it’s absolutely essential to remove all sanding dust. Even small particles can compromise the adhesion and finish of your paint. Use a shop vac to thoroughly vacuum all surfaces of the built-ins, paying close attention to corners, crevices, and shelves. After vacuuming, wipe down all surfaces with a tack cloth or a damp cloth to pick up any remaining fine dust. Allow the surfaces to dry completely before moving on to painting. This diligent cleaning ensures a pristine surface, ready for a flawless paint application.

Step 14: Paint for a Unified, Custom Finish

Now for the transformative step: painting! To create the illusion of one solid, custom-built unit, paint all of your newly installed trim boards with a satin finish paint that perfectly matches the existing IKEA white of the bookcases. We’ve found that Sherwin Williams’ base white paint is an excellent match for IKEA white. At this stage, you only need to paint the added boards, as the Billy bookcases themselves already have their factory finish.

However, if you desire a completely custom color or want to enhance the durability of the entire unit, you can choose to paint the entire built-in. If so, we highly recommend lightly sanding all laminate surfaces, applying a shellac-based primer (like Zinsser B-I-N), and then using a high-quality urethane alkyd enamel paint. Applying paint with a sprayer will yield the smoothest, most professional finish, ensuring excellent adhesion to the veneer and maximum durability. For cabinet and furniture painting, Benjamin Moore Advance is a top choice, known for its hardness and smooth finish. Painting the BILLY bookcase built-ins a different color from IKEA’s factory finishes can truly create a unique, statement-making design element. For more detailed tips on painting laminate IKEA furniture, check out our guide: The Trick to Paint IKEA Laminate Furniture.

Considering the “IKEA hack” origins, the result is truly remarkable!

Step 15: Integrate Oxberg Doors for Style and Storage (Optional)

Adding glass/panel Oxberg doors to the lower sections of your built-ins is an excellent way to introduce concealed storage, protect contents from dust, and add a layer of sophistication. While Oxberg doors are designed by IKEA to fit Billy bookcases, our built-in method with added trim means the standard pre-drilled holes for hinges are no longer in the correct position. This requires a clever modification to properly hang the doors, ensuring they sit flush with your new trim work.

Step 16: Measure and Mark New Hinge Depth with a Combination Square

Because you’ve added 1×2 boards to the front of your bookcases (Step 10), the original hinge holes on the Billy units are now recessed too far to properly install the Oxberg doors. You need to create new hinge holes that account for the added depth of the 1×2 trim. To do this precisely, place a combination square flush against the front edge of the newly installed 1×2 board. Mark this depth on the combination square using a piece of painter’s tape. This mark represents the new, shallower position for your door hinges.

Step 17: Precisely Mark the New Hinge Locations

Using the painter’s tape mark on your combination square as a guide, transfer these new, shallower depth measurements onto the bookcase frames. These new marks indicate exactly where the front edge of your door hinges should align to sit flush with your newly installed 1×2 trim. Mark these new hinge points carefully with a pencil. Repeat this for all hinge locations on each door-receiving bookcase. Precision here ensures your doors will hang evenly and close properly.

Step 18: Drill New Hinge Holes to the Correct Depth

To ensure your new hinge holes are drilled to the correct depth, preventing damage to the bookcase material, use an existing pre-drilled hinge hole as a reference. Insert your drill bit into one of the original Billy bookcase hinge holes. Use a piece of painter’s tape to mark the depth on the drill bit where it meets the surface of the bookcase. This tape acts as a depth stop. Now, using a drill bit suitable for wood, carefully drill into your newly marked locations (from Step 17) to that exact depth, being careful not to drill all the way through the bookcase side. These new holes will perfectly accommodate the Oxberg door hardware.

Step 19: Install Hinges and Door Hardware

With your new, custom-drilled holes in place, it’s time to attach the door hardware. Screw the hinge plates (the part that attaches to the bookcase frame) into the newly drilled holes you created in Step 18. Ensure they are firmly secured and properly oriented. Then, attach the hinges directly to your Oxberg doors according to their instructions. This two-part installation (hinge plates on the bookcase, hinges on the door) will make hanging the doors in the next step much simpler.

Step 20: Hang Doors and Add Decorative Knobs/Pulls

With the hinge plates on the bookcases and hinges on the doors, you can now carefully hang the Oxberg doors onto your built-in unit. Most modern hinges offer some degree of adjustability, allowing you to fine-tune their position for perfect alignment. Take your time to adjust each door to ensure all doors on the built-in unit align properly with each other and sit flush with the surrounding trim. Once the doors are perfectly positioned and operate smoothly, add your chosen decorative pulls or knobs. This final touch not only enhances functionality but also significantly contributes to the custom, high-end aesthetic of your new built-in bookshelves.

Style Your Beautiful New Built-In Shelves

Now for the fun part – styling your finished built-in bookshelves! This is where you can truly infuse your personality and bring the room to life. Beyond simply stacking books, consider creating visual interest by alternating between vertical stacks and horizontal arrangements of books. Intersperse these with decorative objects, such as unique sculptures, framed photos, small potted plants, or cherished travel souvenirs.

Play with varying heights, shapes, and textures of your decor items to create dynamic vignettes. Don’t be afraid to leave some negative space; not every shelf needs to be packed. Grouping items in odd numbers (threes or fives) often creates a more pleasing aesthetic. Consider incorporating baskets or decorative boxes within the closed Oxberg doors for discreet storage of less attractive items. Step back frequently to assess the overall balance and make adjustments until you’re delighted with your display. For more inspiration, check out our Tips for decorating shelves.

And there you have it – another successful IKEA Billy bookcase hack complete! While we initially didn’t plan on using these specific skinny shelves, the outcome proved to be incredibly rewarding. This configuration actually results in an even sturdier unit than wider versions, offering more support for a greater number of books. The satisfaction of transforming affordable, off-the-shelf items into a custom, high-end feature for your home is truly unmatched.

You can view the fully finished home office for a complete look, including all paint colors and décor/furniture sources we utilized to bring this space to life.

Explore More DIY Built-In Ideas

If this project has sparked your inner DIY enthusiast, here are more inspiring built-in projects to tackle:

DIY IKEA Built-In Closet Hack With Billy Bookcases

DIY IKEA Bookcase Built In Shelves

How to Make Built In Cabinets and Window Seat

DIY Window Seat Using a Kitchen Cabinet

More Creative IKEA Hack Ideas

• 30 Inspiring IKEA Pax Closet Makeovers
• The Trick to Paint Laminate IKEA Furniture
• DIY IKEA Pantry Cabinet Using Hemnes
• 5 DIY IKEA Storage Hacks We’ve Used and Recommend

Equipment

• 1 Circular saw or table saw
• 1 Coping saw or jigsaw
• 2 Saw horses
• 1 Power drill
• 1 Set of drill bits
• 1 Orbital sander
• 1 Pack of medium/fine grid sanding pads
• 1 Cordless brad nailer gun
• 1 Hammer with claw
• 1 Pry bar
• 1 Tape measure
• 1 Step ladder
• 4 Clamps
• 1 Combination square
• 1 Utility knife
• 1 Shop Vac

Materials

• 8 Billy Bookcases, size 15 3/4″ x 93 1/4″
• 4 long glass/panel style Oxberg doors
• 4 short glass front style Oxberg doors
• 1 box wood screws, size #8 1 1/2″
• 5 boards 2x4x8 studs
• 2 boards pre-primed 1x10x8
• 4 boards pre-primed 1x4x8
• 1 box finishing nails
• 2 canisters white latex caulk
• 1 tube wood filler
• 1 can Loctite foam for gaps
• 1 roll Frog tape
• 1 quart satin finish interior paint matched to IKEA shelves
• 1 2″ angled paint brush
• 1 foam paint roller – mini size
• 1 paint tray
• 1 pencil
• 8 cabinet knobs or pulls

Instructions

Remove Baseboard

1. To get the Billy bookcases as flush as possible to the back wall, remove the baseboard. Use a utility knife to cut along the caulk lines of the baseboard. Then, use a claw back hammer and a small pry bar to pull the baseboard away from the wall.

Assemble Bookcases

1. Assemble all of the boxes of the Billy bookcases, including the top extension. Leave the bookcases without the thin backing that comes with them since the back wall will become the bookcase backing since you’re building them in. You can keep the top extension off until after you anchor the bookcases to the wall.
   

   
   

Correct Gap

1. Since the bookcases are designed to have a backing (but it’s best not to have one in a built-in to allow access to outlets), there will be a small gap at the back. To make this look seamless, measure the bookcase and cut a piece of 1×2 board. Attach the 1×2 to the back of the bottom of the bookcase with the finish nailer. And the gap is gone! Caulk will fill any cracks later.

Anchor Shelves

1. Measure your wall and make sure the bookcases are centered and place where you want them. Anchor the middle bookcase.

Attach Each Billy Bookcase Together

1. Use your clamps to tightly hold together the sides of two bookcases. Then, screw the wood screws through both sides of the bookcases to secure them to each other.

Build In the Gaps

1. See that little bit of space around the sides and top of the Billy bookcases? We want to fill that in to make the bookcases look like built ins.

Attach 2x4s

1. In the small gaps, drill 2x4s to the wall and the side of the Billy bookcases. Do the same for the top of the shelving unit too.

Attach 1×4 Boards to Face

1. To make the bottom of the bookcases look like one solid built-in piece of cabinetry, attach 1×4 pre-primed boards with finishing nails. Use a coping saw or jigsaw to cut out the sides of the boards to mimic the shape of the baseboard on the wall. It doesn’t have to be perfect as caulk can later fix imperfect cuts. Repeat the process for the top of the Billy bookcases, coping the sides of the 1×4 boards to fit the crown molding.
   

   
   

Cut 1×10 Boards to Fit Sides

1. Since the sides of the bookcases typically aren’t the exact width of a board, measure the gap between the bookcase and the wall and cut down the 1×10 board to fit as the face on the sides using a circular saw or table saw.

Attach 1×2 Boards to Front

1. Use the finish nailer again to attach 1×2 boards to the fronts of the bookcases to hide the cracks where the bookcases meet together.

Fill Gaps, Cracks, and Nail Holes

1. Use Loctite foam to fill any larger gaps. We used it to fill the small gap between the bottom 1×4 and the bottom of the bookcases since it was slightly too big for caulk. Once dry, cut the foam and sand it smooth. Use caulk to fill any cracks between the wall and boards. Then, use wood filler to cover any nail holes or cracks in the boards where they meet. Let dry.

Sand Smooth

1. Once all of the fillers are dry, use an orbital sander to smooth it out.

Remove Dust

1. Use a shop vac to remove any sanding dust from the built ins to make it ready for paint.

Paint Boards

1. Paint all of the visible boards with the satin paint you had matched to the bookcases to make everything look like one solid piece of built in bookshelves. You don’t have to paint the Billy bookcases themselves, just the boards so they’ll match them.

Add Doors (optional)

1. Add glass/panel Oxberg doors to the front of a few of the bookcases to provide some concealed storage. Oxberg doors are designed by IKEA to fit Billy bookcases, but by making these built in, there’s a trick to hang them properly.

Mark on a Combination Square for 1×2 Depth

1. Since the existing holes on the Billy bookcases are no longer useful for hanging Oxberg doors as they are intended in design, you have to make new holes to account for the depth of the 1×2 boards added to the front of the bookcases. Place a combination square against the 1×2 and mark its depth with painters tape.

Mark the New Hole

1. Use the marking on the combination square to mark new holes closer to the front of the bookcases.

Mark the Hole Depth on a Drill Bit and Drill a New Hole

1. Place your drill bit inside of an existing bookcase hole. Use tape to mark where the hole stops so you know how far to drill the new holes. Drill into where you marked for the new holes to that depth.

Attach Hinges and Door Hardware

1. Screw the door hardware into the new holes you drilled, and attach hinges to the doors.

Hang Doors and Add Knobs

1. Hang the Oxberg doors to the bookcases, and check to make sure all doors on the built in unit align properly. Then add pulls or knobs.
   

   
   

Have you embarked on your own DIY built-in bookshelves project before? Or perhaps tackled another ingenious IKEA hack? If not, be warned: once you complete your first one, you’ll likely be hooked! These projects truly offer the best of beginner-level carpentry with “training wheels,” providing immense satisfaction and a custom look without the overwhelming complexity.

Most Frequently Asked Questions About IKEA Billy Bookcases