DIY Project: Built-in IKEA BILLY Bookcase

Here’s the ultimate “shelfie”… A DIY customised bookcase that started its life as IKEA Billy shelf units and now looks like custom cabinetry.

DIY Project: Built-in IKEA Billy bookcase

Kylie writes: This DIY project takes place in my home office. At one the end of the room, the ceiling is lower to allow for bathroom plumbing on the second storey and the bulkhead ceiling has created a nook that lends itself to built-in bookcases. In anticipation, during the renovation we included LED down-lights in the bulkhead, but didn’t have enough money left in the budget for cabinetry.

Two, maybe three years later (more like four), we finally got tired of working among piles of books and paperwork and decided to bite the bullet on the bookcase project. We shopped around for cabinetry quotes and experienced a debilitating case of sticker-shock when the cheapest one came back at just under $4000. That's when we decided that we would build the bookcase ourselves - and there was no better to place to start than with our favourite Scandinavian flat-packs!

Customise an IKEA Billy bookcase system project blog

Design and select your IKEA BILLY bookshelf combination

IKEA Billy bookcase hack

Built-in IKEA billy bookcase project: select unit combination

We sketched out the space and selected a combination of Billy bookcases to fit the width and height of the area. In our case, we chose:

  • 2 of W80 cm x H202 cm units
  • 3 of W40 cm x H202 cm units

Built-in IKEA Billy bookcase project

Assemble the flat-packs

IKEA Billy bookcase hack

When it came to assembling the units, we elected to use the plain-white back pieces supplied by IKEA, but you could choose to leave them off to reveal the painted wall behind or you could use an alternative covering, such as wallpaper:

Option: wallpaper the back of your Billy bookcase

Image credit: Centsational Girl

Step 3: Built-in IKEA Billy bookcase project

Build a base for the shelf units to sit on

IKEA Billy bookcase hack

Built-in IKEA Billy bookcase project: build the base

To achieve a built-in look, you'll want to raise the units off the ground to allow for finishing wood and a skirting (kickboard) across the front.

We removed the existing skirting from the wall and set it aside to reuse on the front of the bookcase later.

We then measured and trimmed the skirting boards on the side walls. To cut the skirting board on a 45-degree angle, we used a multifunction tool

For the base, we built a basic wood frame—see photo above. Adjust the height of your base according to the size of the finishing wood and/or kickboard you wish to use.

Step 4: Built-in IKEA Billy bookcase project

Add side and top framing

IKEA Billy bookcase hack

Built-in IKEA Billy bookcase project: build side frame

The IKEA Billy units are eventually going to look built-in because finishing timber will hide the gaps between each shelf unit and the contacting walls and ceiling. But first you need some framing wood in place so that you have something to attach the finishing wood to.

Now that the base is built, position the bookshelf units into place, taking care to space them evenly. In our case, we were left with a 5 cm gap between the wall and shelf units at each end. Here we attached strips of structural wood to the walls using drywall/Gyprock anchors and screws. Don't worry - finishing wood will eventually cover the structural wood. Likewise, we attached structural wood to the ceiling and back wall.

 Built-in IKEA Billy bookcase project: Step 5

Position your Billy units and anchor them to the wall

IKEA Billy bookcase hack

IKEA Billy bookcase hack: position units into place and anchor them to the wall

This is where the project really starts coming together! We positioned the Billy shelf units onto the base and ensured that they were spaced evenly before screwing them into place using the anchors supplied with the units by IKEA.

IKEA Billy bookcase project: Step 6

Attach finishing wood and kickboard to the front

IKEA Billy bookcase hack

IKEA Billy bookcase hack: attach front finishing wood

Before adding skirting board to the front, we nailed a piece of 145 mm finishing wood onto the base to conceal the framing and bottom of the units.

Note: The bottom shelf on Billy units is slightly shorter than the sides. This leaves a narrow gap that we caulked with Selley's 'No More Gaps' before painting. Your other option would be to notch the back of the plank, but that seemed like too much effort. 

We then nailed the original skirting board to the finishing timber.

 Built-in IKEA Billy bookcase project: Step 7

Attach finishing wood to the top

IKEA Billy bookcase hack

IKEA Billy bookcase hack: attach finishing wood to the top

We repeated Step 6 with a finishing board across the top of the units. We clamped a couple of pieces of off-cuts in place to help position the finishing board while we screwed it into the structural frame.

Built-in IKEA Billy bookcase project: Step 8

Attach finishing wood to front

IKEA Billy bookcase hack

IKEA Billy bookcase hack: attach trim timber to the front

For the finishing trim on the front of the unit, you want to select a suitable width to cover the gaps between the units and wall ends. In our case, we chose 65 mm pre-primed trim wood.

We attached these to the Billy units (and framing wood at each wall end) with finishing nails.

Knock the heads in with a nail punch.

Built-in IKEA Billy bookcase project: Step 9

Install cornice (crown moulding) then prepare and paint

IKEA Billy bookcase hack

IKEA Billy bookcase hack: prime and paint

We bought a length of cornice (crown moulding) that we cut to length and cemented into place with cornice cement.

Then we filled all the nail and screw holes (so many holes!) with wood filler and sanded all of the wood surfaces.

We caulked the larger gaps with Selleys 'No More Gaps', then primed any raw wood before giving all of the exposed finishing wood two coats of semi-gloss acrylic paint.

IKEA Billy book shelf hack

There you have it! We estimate the savings at around AUD$3000. Yes, it did take a weekend of concentrated effort, but no major carpentry skills were required, we had fun and the results were definitely worth it!

IKEA Billy bookcase hack

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