If you’ve ever priced out a custom window seat with storage, you know the numbers can be depressing. I looked at quotes for a simple built-in bench and nearly fell off my chair. So I went the IKEA hack route instead. And honestly, the result looks just as polished for a fraction of the cost. This DIY window bench using IKEA BESTA units is the budget-friendly project you’ve been scrolling past thinking it’s too hard. It’s not.
Why I chose BESTA for this window seat project
Look, I’m not someone who owns a table saw or a pocket hole jig. I needed something that didn’t require custom cuts or special joinery. The BESTA system is basically a flat‑pack rectangle that you can stack, combine, or mount. You don’t need to be a woodworker to get clean lines. I picked BESTA because the depth (15 inches) is just right for a window seat. It’s not too deep awkward like a standard cabinet, and not too shallow to sit on without your knees hitting the wall. Another win: you can buy just the frame, skip the doors, and add a nice top. That keeps the bill low.
How to choose the right BESTA units for your window
Measure the width of your window opening, sill to sill, or the whole alcove if you have one. Write it down. Then go to IKEA’s website and look at BESTA frame sizes. The most common width is 23 5/8 inches. I used two frames side by side for my 48‑inch window. Three frames would work for a wider bay. Here’s the thing: you don’t need to buy identical doors if you want storage with a face. I actually left one frame doorless for my cat’s little hidey‑hole. That’s the kind of flexibility you get. Also, think about height. The standard BESTA frame is 25 1/4 inches tall. Add a 1‑inch top and you land close to standard chair height (about 17‑18 inches seat height if you add legs). If you want lower, look for the shorter BESTA frame (15 inches tall).
Full product list for this IKEA hack window bench
I’m listing exactly what I bought. No guessing, no “you might also need”.
- 2x BESTA frame (23 5/8x15x25 1/4) – around $40 each
- 4x BESTA legs (Capita are cheap and metal, or try the wooden one if you want a warmer look)
- 1x BESTA top panel (or a piece of butcher block cut to size – I used a simple white LACK shelf because it was on sale. Not gonna lie, it’s not perfect but it works)
- Optional: 2x BESTA door for the storage side (I used a single LACK shelf as a door on one unit. That’s not standard, I just screwed hinges into the side. Honestly it took an extra 20 minutes but saved me $15)
- Screws, brackets, and wall anchors if you want to secure it to the wall (I did, because my toddler likes to climb)
Total cost for me: around $110 including tax. That’s for a 48‑inch window bench that looks built‑in. A custom carpenter wanted $800. So yeah, worth it.
Step‑by‑step instructions for building an IKEA BESTA window bench
Assemble the BESTA frames according to the IKEA instructions. That part is boring but easy. Just don’t lose the little cam locks. Once both frames are done, attach the legs. I placed them at the corners of each frame plus one in the middle of the combined unit. Then you connect the frames side by side. BESTA frames have pre‑drilled holes on the sides. I used small L‑brackets to screw them together. No need for special hardware. Now, here’s the slightly tricky part: the top. If you use a BESTA top panel from IKEA, it just sits on and you screw from underneath. But I wanted a thicker top. I bought a cheap 12×48 inch pine board from Home Depot, sanded it, and painted it white. Then I attached it with wood screws up through the frames. Not gonna lie, I had to re‑drill one hole because I misread the bracket placement. That’s the kind of thing that happens. It’s fine. You won’t notice.
Customizing your IKEA window bench without spending extra
You don’t have to buy fancy hardware. I used leftover paint from another room to match the trim. A roller and a brush, that’s it. If you want a cushion, you can sew one yourself or buy an inexpensive bench cushion online. I found a 46‑inch cushion for $25 on clearance because the pattern was ugly. I threw a neutral cover on it. Problem solved. Another idea: add a small trim piece along the front edge of the top to hide the seam between the two frames. That’s just a quarter‑round molding from the hardware store, about $3. Nail it on, caulk the gap, paint. Suddenly it looks like a million dollars. Or at least like a thousand.
Common mistakes to avoid when building an IKEA window seat
First: don’t assume your window sill is perfectly level. Mine wasn’t. The floor was off by half an inch, which meant the bench rocked slightly. I slid a thin shim under one leg and trimmed it with a utility knife. Easy fix. Second: don’t skip attaching it to the wall if you have kids or heavy cats. I used a simple L‑bracket screwed into a stud behind the bench. Third: measure your cushion BEFORE you buy the top board. I bought a cushion that was wider than the bench, and I had to cut the top board down. That’s extra work. Measure twice, cut once. Or in my case, measure twice, buy the wrong cushion, cut anyway.
Also, a weird personal detail: my dog insisted on sitting on the frame while I was trying to attach the top. I had to bribe him with treats to move. He now has a designated spot on the bench. He knows it’s his.
Is an IKEA window bench really budget‑friendly?
Yes. Look, you can spend $200‑300 if you buy doors, legs, a nicer top, and a cushion. That’s still less than half of a custom built‑in. And the build time? About one weekend afternoon if you’re slow like me. I’m not a fast builder. I stop to drink coffee and check my phone. Still done by dinner. The storage inside is generous. I keep board games in one frame and winter scarves in the other. That’s two problems solved: seating and chaos containment. Honestly, the hardest part was deciding between white and black legs. I went with white because my trim is white. But black would have been fine too.
So grab your BESTA frames and a weekend. You’ve got this. And if you do build it, I’d love to hear how it turned out. Drop a comment or tag me on Pinterest. Happy hacking.
#IKEAhack #DIYwindowbench #IKEABESTA #budgetdiy #windowseat