How to Assemble an IKEA BILLY bookcase

What You Need Before You Start

The BILLY bookcase is IKEA's bestselling bookcase — simple, adjustable, and practical. Assembly time is typically 45 min - 1 hour for an experienced assembler — allow double that if it's your first time. Before you open the box, gather the following:

• Allen key (included in box, but a power driver version saves time)
• Phillips screwdriver (or a drill with a PH2 bit)
• Rubber mallet (essential — never use a metal hammer on dowels)
• Spirit level (critical for wardrobes and shelving)
• Blanket or cardboard sheet (to protect floor and surfaces)
• A second person (strongly recommended for this item)

Step-by-Step Assembly Guide

Step 1: Unpack and Sort Hardware

Unpack every box completely before starting. Lay all hardware out on a flat surface and sort by type: cam locks, dowels, bolts (long and short separately), hinges, and any brackets. Count them against the parts list in the instruction booklet — now is the time to spot a missing part, not halfway through the build.

Keep hardware in the bags or small containers until you need each type. The worst thing you can do is tip everything onto the floor and try to build from a pile of mixed fasteners.

Step 2: Protect Your Surfaces

Lay the largest panels flat on a blanket or sheet of cardboard. The finished surfaces scratch easily during assembly — a £10 moving blanket saves you the heartbreak of a damaged panel. Work in a room with enough space to lay the full unit flat before standing it upright.

Step 3: Build the Main Carcass

Follow the numbered steps in the instructions. Keep all fixings loose until the main frame is together — tightening as you go locks in any misalignment and makes it impossible to correct later. This is the most common mistake DIY assemblers make.

Pay close attention to part orientation — most panels have a correct side, and instructions show this with subtle shading. When in doubt, look at the cam lock holes: they should face inward.

Step 4: Check for Square

Before tightening anything fully or fitting the back panel, check the unit is square. The fastest method: measure diagonally corner to corner in both directions. The measurements should be equal. If not, apply gentle pressure to the longer diagonal while checking — the frame will shift slightly before the fixings set.

A spirit level across the top also confirms no twist in the frame. Get this right now. Once the back panel is on, you cannot adjust without dismantling.

Step 5: Fit the Back Panel

The back panel is structural — it's what keeps the unit square permanently. Align it carefully with all edges flush, then fix progressively from one corner. Don't hammer all nails in fully until you've checked it's sitting flat at all four corners.

Step 6: Stand Upright and Fix to Wall

For wardrobes and tall units, this step requires two people. The unit is top-heavy and will tip if stood with one person. Once upright, fit the anti-tip wall bracket — this is not optional. Building regulations and IKEA's own guidance require wall fixing for tall units, especially in homes with children.

Step 7: Fit Doors and Accessories

Hang doors using the supplied hinges. Most IKEA hinges have a 3-way adjustment (up/down, in/out, side to side) — use all three to get doors perfectly aligned. Step back and view from a few metres away to spot any misalignment your eyes miss up close.

Common Issues with the IKEA BILLY bookcase

The most frequently reported issues are: Back panel not flush, shelf pins placed wrong holes. Here's how to avoid them:

The single biggest cause of all these issues is rushing the early steps. If the carcass is square and all fixings are tight before fitting accessories, the common problems largely disappear. Take your time in steps 3 and 4 — it saves time overall.

How Much Does It Cost to Have it Assembled Professionally?

If you'd rather skip the build entirely, our professional assembly service starts at £40 for a single BILLY bookcase. This includes full assembly, alignment, and a 30-day guarantee. We operate across the UK, 7 days a week.