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How to Build a Custom Bunk Bed

Follow these steps to plan and build a safe, wall-attached bunk bed for your growing kids.

by Mark Clement

To say that a bunk bed has a lot riding on it is an understatement. However, they can be made safe and to accommodate growing children while still remaining temporary parts of the bedroom as family needs change. Plus, they’re a fun DIY project to have.

Here’s a step-by-step guide to planning and building a built-in wooden bunk bed with a desk underneath the bed platform for your teen.

DIY Bunk Bed Planning

Bunk bed design is kind of like pergola design in a sense: There are no real rules. Bunk beds, like pergolas, can take just about an infinite number of forms and we all know one when we see one. Moreover, we know when they look right and when they, well, miss the mark.

Still, there are two main forks in the road when planning your bunk bed:

  • Ceiling height
  • Then, deciding whether to make your bunk bed free-standing or attached to the wall — like our TOH Beach House bunk room.

While this article focuses on a simple built-in design with a desk underneath the bed platform for a teenager, the components of a bunk bed usually have the same five main parts:

Designing Your Bunk Bed

Whatever you design, bunk beds are something that lend themselves to laying out in place rather than relying solely on paper. Blue tape and cardboard are two main items that’ll enable you to “see” how your bunk bed plan will work before cutting a single board. This is important because things like travel lanes through the room, door swings, furniture placement, even lighting, and electric, can all be affected by the addition of a bunk.

The other—and maybe the biggest—concern is how much room you plan to allot between the top of the mattress and the ceiling. The “rule” is that your child should be able to sit up and reasonably move about while also being able to mount and dismount the ladder easily. A 9-foot ceiling is ideal for a bed like this.

Planning Steps:

  1. Pick the design you want as that’ll determine the materials selection. One of the cool things about bunk beds is that you can make them from premium, furniture-grade plywood or rustic, organic-looking 5/4 pine or 2-by framing and still get a cool look no matter what. This article focuses on using commodity lumber.
  2. Run a piece of blue painter’s tape vertically on the wall in the proposed bed location. Start from the ceiling and measure down to where you think the top of the mattress should be and mark its position on the tape.
  3. Next, mark the mattress thickness on the tape—mattresses come in a wide variety of thicknesses so you’ll have to figure this out before getting started. Bunk beds typically don’t include a box spring, so it’s only necessary to account for the mattress in your layout.
  4. This gets you to the top of the mattress platform which I usually make from ¾” plywood. Mark that thickness on the blue tape.
  5. Since the mattress platform is usually supported by a 2×2 cleat fastened inside the mattress box, account for the full thickness of the mattress box. 2×6 or 2×8 generally works. Now you can see in real-time how everything lays out. Tommy might call it a story pole.
  6. Also, consider that your child is going to want a place to put down a drink, electronics, a book, or all of it. And you need clearance around the mattress for making the bed. So plan a “halo” of 12-16-inches on at least 2-sides of the mattress.
  7. Next, using blue tape or cardboard, map out the mattress box on the floor space. This shows you how the bed will affect passage in the room which is really hard to figure out from a drawing on a piece of paper.
  8. Once the height and positioning are all worked out, it’s time to start cutting boards.

Building Your DIY Bunk Bed

For a piece of furniture, this type of bunk bed has a lot in common with deck framing. Get started with a ledger board. The ledger needs to be cut to a specific length.

Pro2Pro Tip: Put blue tape on your level to keep it from marking up the wall.

Steps for Building a Bunk Bed:

  1. If your bed is 8-feet long and you’re building the frame from 2-by (1 ½-inches thick) lumber, cut three inches off the ledger. This way, later, you can fasten the left and right sides of the mattress box to it and the whole thing nets out to 8-feet.
  2. Locate the studs and fasten your ledger in place with two 3-inch deck screws per stud. Make sure it is level.
  3. Install the left, right and front of the box frame. Use temporary posts to hold the left and right pieces level while you install the permanent posts. 2x6s fastened at right angles to each other, forming an “L” shape, work well as posts. If there is carpet, compress it so that the box frame remains level once the weight is applied.
  4. Square up the box by taking diagonal measurements of the bed frame and jimmying the frame’s outer corners until your measurements are equal. Install the 2×2 cleat inside the mattress box.
  5. Next, install the mattress platform, and the bed rail that’s an essential safety feature. You’ll need to build a sturdy ladder to make the bed easily accessible. This type of ladder could be made from clear, ¾”-thick pine or oak. For safety, the top of the ladder should be screwed to the bed frame.
  6. Once you’re finished with the bed, you can build or install a desk underneath, if you’d like. Thirty-six inches high is a good place to start.
  7. Then set aside a day to apply the finish. Urethane, boiled linseed oil, or semi-gloss paint all make great finishes.
  8. Lastly, since everything is screwed together, when the day comes it’s no longer bunk bed world, everything comes apart easily and wall repair is minimal.

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