We’d been talking about adding a bookcase to the office/guest room/playroom for a while—bookcases are great for storage, display, and adding architectural height. After measuring the wall to the left of the off-center window, we decided that a slim bookcase would fit perfectly and headed to IKEA with our measurements. A few hours later we were back home assembling a $69 Billy bookcase.

We considered other IKEA options like the Expedit and the Lack, but the Billy’s height and width were a near-perfect fit for that wall, and the price made it easy to justify some small custom tweaks. When we test-fit it, the baseboard and shoe molding prevented the bookcase from sitting flush. A quick trip to the garage for a coping saw and about ten minutes of careful trimming fixed that—after sawing a small notch to accommodate the molding the unit slid into place and looked like it belonged.

With the bookcase installed, the room immediately felt more balanced. The added vertical mass on the right side of the wall complemented the window on the left, and the narrow footprint meant it fit beside the sleeper sofa without crowding the space. That said, the factory back panel bothered us: the thin, folded cardboard panel had permanent creases from packaging and looked flimsy once nailed into place.

We brainstormed a few fixes. One plan was to cut foam core to fit each of the six rectangular openings in the back and cover them with paint, wallpaper, or fabric. That would have been tidy, but time-consuming and a little excessive. Then we had a simpler idea: remove the back panel entirely and paint the wall behind the bookcase to create a built-in look.

After taking off the cardboard back, we taped a rectangle on the wall with the bookcase in place so we’d know exactly where to paint. We used leftover paint—a soft aqua that previously covered a nursery ceiling—which blended nicely with our blue-green sleeper sofa and cost us nothing. Once the painted area dried, we slid the bookcase back into place and liked how the painted backdrop read like a built-in niche.

Removing the back did create a couple of cosmetic issues: a dark shadowed recess inside the unit and the visible rows of shelf-pin holes. We grabbed white caulk and filled most of the extra holes, leaving one hole above and below each shelf in case we wanted to readjust later. The caulk matched the bookcase color closely and smoothed out the ridge where the back had been, so the shelves looked cleaner and more finished.

Structurally, losing the back panel slightly reduced the bookcase’s rigidity. It wasn’t dangerously wobbly, but it didn’t feel as reinforced without the cardboard. Anchoring the top of the unit to the wall improved stability considerably. For extra security and child safety, we plan to add metal L-brackets painted white so they’re nearly invisible; that will make the bookcase feel rock-solid and give us additional peace of mind.

We filled the shelves with a mix of functional and decorative items so the room could work as both an office and a welcoming guest room. Before styling, we made a short inventory of what needed to fit so the unit would be useful as well as pretty:

• office supplies: envelopes, tape, scissors, stapler, notepads
• extra printer paper and cardstock
• paint decks for quick reference while working on projects
• books and binders
• a small clock for timing feedings and breaks
• a few of Clara’s favorite stories and toys
• a container of treats for our dog, Burger

Baskets purchased on sale hold items we’d rather keep out of sight, like office supplies, extra paper, and children’s books and toys. Open shelves display books, binders, a glass jar of dog treats, and a few decorative vases and frames so the unit doesn’t read as purely utilitarian. We even had a small white planter we could tuck in the corner to store mailing tubes used for shipping shop orders, which added another bit of organized storage.

We still have files and paperwork to sort on the desk side of the room, but overall the $69 bookcase plus leftover paint added useful storage, visual interest, and a built-in feel to the space. It was a quick, budget-friendly upgrade that met both our practical needs and our design goals.

Want to follow the entire office/guest bedroom/playroom makeover? Check the introduction post, the sleeper sofa roundup, the DIY desk play-by-play, and the homemade light fixture project for the full series.