Lofty Lair: a Simple Bunk & Desk in Limited Space

My daughter wanted a new bed frame. I wanted to make her a simple, easily constructed twin-sized bed loft made from 2x4s, .5” plywood sheets, and construction screws. (It had to be as simple as possible due to limited confidence in my ability to complete any more complicated project.) It needed to hold an 8” twin mattress 2’ from a 91” tall ceiling in a 44.5" by 85" footprint. I wanted the design to include a desk/bookshelf tucked behind its ladder.

1. 2x4s (around a dozen)
2. .5" x 4' x 8' plywood sheets (2 or 3)
3. Tape measure
4. Favorite pen/pencil
5. Electric screwdriver/drill
6. Table/circular saw
7. Jigsaw (optional)
8. Trigger clamps & a square jig (optional)
9. Orbital/belt sander and/or sandpaper
10. Primer paint/stain/urethane (and preferred brushes & drop cloth)
11. 2 1/2" star driver construction screws (~ 100)
12. 1 - 1 3/4" star driver construction screws (~ 25)
13. Square
14. Level

Begin by listing out the defining rules of a successful result. (Otherwise it'll be surprisingly easy to accidentally make some decision that betrays one of your unwritten rules.) For this project, I want the loft bed frame to be:

1. Simple - Made from the fewest pieces - and none should ever require complicated cuts.
2. Functional - Should hold a large number of books on bookshelves behind the ladder steps.
3. Fit a twin bed - Must fit in a 44.5” x 85” footprint in the corner of the room and hold the mattress no closer than 2’ from the ceiling.
4. Ladder on side - Do not position the ladder at the end of the bed (it would obstruct the closet door.)

At this point it's also helpful to make a "mood board"-type collection of inspiration. (Just copy-paste images of similar projects that you like. Then take a breath and try to identify what it is about your mood board you'd like to emulate.)

The basic physical constraints for this particular project is also pretty simple: There are only 2 corners of the bedroom large enough for a bed frame. The "better" corner has a window 44.5" from the corner and a closet door is on the adjacent wall 85" from the corner. The ceiling is 91" from the floor. There was also an outlet next to the closet door on the longer wall.

I chose Blender for my CAD program because it is free and works well for visualizing projects. The design step can be completed more quickly if you have familiarity with the program, but it has a pretty intuitive learning curve. Focus on getting comfortable with viewport navigation, edit mode, and keyboard command shortcuts. Remember to keep your parts organized in the outliner as you go. Otherwise you'll have more trouble later, when you have hundreds of objects to sift through.

Whether you're drawing or sculpting or programming or modeling, experts advise that you should start by blocking out the basics and then refine and progressively add details.

I started by creating walls, the ceiling, and the floor in my CAD program. Then, 24” from the ceiling, I added a 8” x 38” x 75” cube and added a bevel to make it look like a mattress. Under that, I added a panel with 5/32” x 38” x 75” dimensions for the mattress pad. I knew that I wanted this panel to rest on 2x4s so I created 1.5” x 3.5” “spines” and “ribs” positioned underneath. This frame would be screwed to the legs around each corner which are positioned so that only the wider face is visible facing outward.

I knew that I wanted the ladder to be sloped so I positioned the steps first. The top step is about as far down from the mattress top as each step is from the next. (None of them actually overlap the footprint of the last.) 4 steps, placed 13” (and 3.5”) apart, results in a 15° ladder that looks like I want. At this point I realized that the ceiling is 91” above the floor and 91 is divisible by 13. So I moved everything down so the top of the mattress would end up 26” from the ceiling & the desk surfaces match the ladder’s first 2 steps.

Your own design, built within your own different constraints and preferences would definitely end up different.

I placed my “constraint” objects in their own collection and positioned them on the other side of the axes from the design so that all the parts’ dimensions can easily be based off of a 0 origin. I used keyboard shortcuts for most of the transformations. (Keying G > Y > 1.5 or R > X > 15 will result in more precisely positioned parts than moving and rotating by hand.)

Take the opportunity to make as many sanity checks as your assembly affords you. In this case, you have a very cool (and very easy to use) option: linking to Google's Scene Viewer to view your design's model overlaid on your cellphone's camera view.

There are only a few prerequisites. You need:

1. An Android smart phone with updated Google app & Google services.
2. To be able to upload your design's model as a GLB or GLTF file to a web location your phone can access.
3. Finally, you need to make a link to follow on your phone. The link will look something like this:

intent://arvr.google.com/scene-viewer/1.0?file=[file_location]&mode=ar_preferred&resizable=false&title=Project+Preview#Intent;scheme=https;package=com.google.android.googlequicksearchbox;action=android.intent.action.VIEW;S.browser_fallback_url=https://developers.google.com/ar;end;

If you can meet all those prerequisites, you'll see your model on your phone's screen and you can move around the room where the bed frame will be placed and you'll see whether it works in that space. (It's better to realize now that the ladder is going to block the door to your room rather than figure that out when you've attached the ladder.)

Click here for an example.

After you’re happy with the design, inspect each piece and note the important dimensions in the item properties. Organizing the scene collection (and renaming objects as they’re created) helps this process.

For the 2x4s, this is the resulting list for my design:

1. For the legs:
2. (4) 71.5”
3. (2) 64”
4. (1) 56.5”
5. For the mattress frame:
6. (1) 75”
7. (1) 57.5”
8. (2) 39.7”
9. (3) 35”
10. For the ladder:
11. (2) 59.4”
12. (4) 14.5”
13. For the rail:
14. (1) 52.5”
15. (1) 19.3”
16. For the braces: (I just used cutoff pieces.)
17. (2) 20”
18. For the desk supports:
19. (1) 52”
20. (1) 48.5”
21. (2) 16.5”
22. (2) 14.5”

For the panels, this is the resulting list:

1. For the mattress frame:
2. 38” x 75”
3. For the headboard:
4. 38” x 16”
5. For the desk:
6. 16” x 48.5”
7. 16” x 45”
8. 18” x 47.8” (15° cut off the end)

At this point, I saved a copy of my design file and made a reference 0.46875" x 48" x 96" 'cube' and placed it on the XY plane. Then I moved and rotated all the panels to see how many panels I'd need at a minimum to get the desired pieces. In my case, I ended up deciding that the project would need:

1. 3 three foot 2x4s
2. 1 four foot 2x4
3. 11 six foot 2x4s and
4. 2 eight foot 2x4s
5. 3 four foot by eight foot plywood sheets
6. 100 two and a half inch #8 construction screws
7. 25 one inch #8 construction screws

The good news for me is I had most of these supplies left over from previous projects!

First, we assembled the mattress frame. We used clamps to pull any twisted boards into “plumb” and used squares to confirm squareness. We attached the 3 shorter rafters/ribs first, and then attached the first longer rib (the rib that will connect with the top left corner of the ladder.) Next, we measured opposite corners to see how “out of square” we were so far. We were within ⅛” so then we attached the 38” x 75” twin mattress board. Lastly, we attached the final “rib” to the mattress panel and the longer “spine.”

Setting the mattress frame aside, we next assembled the ladder. We knew that we wanted each step to be 13” above the last and this means that each is positioned 13.46” along the ladder railings from the last. We marked the railings with that spacing and then held the upper, forward corner against that mark while screwing together the ladder. 

For all the assembly, we used around 100 2 ½” #8 construction screws with star drive heads and about 25 1 ¾ #8 construction screws with star drive heads. Even though I carefully planned the placement of screws in the design and expected to drill pilot holes, the use of construction screws meant in the actual construction, we could just drive the screws wherever made most sense in the moment.

The legs were pretty easy. As long as we didn’t yet have preference for which end was “up,” it didn’t matter which 2x4 was screwed into the other. We just screwed pairs of the legs together and then carried all these assembled sections to the bedroom where the loft would end up.

First, we marked on the legs where we want the mattress frame to end up. Then we lifted the mattress frame and clamped the frame to the legs near to the mark. (The clamp only needs to be strong enough to hold it temporarily while we position the other legs.)

Because the ladder is the least forgiving of the legs in regards to the mattress height (placing it poorly will result in the feet of the angled ladder to not rest flat across the floor, or the points at the top to not match with the exposed ribs on the mattress frame.) We held the mattress frame so it matched with the top of the ladder and the ladder feet were flat and screwed the pieces together. Then we just went around to each remaining leg and, while consulting a bubble level resting on the mattress panel, raised the mattress frame until it was level and the leg was plumb vertical and then screwed the legs to the mattress frame. Finally, we simply screwed the 45° offcuts as braces on the inside of the legs, under the mattress frame.

Next, we screwed the supports for the desk into the legs (and ladder.) The angled braces, the headboard, and this non “square” shape at the end lends surprising strength to the loft even before we add the remaining panels to the desk. We also attach the 2x4s for the railing with plentiful screws.

Finally, we cut the panels for the horizontal surfaces for the desk and the “front” panel and attach them to the supports.

This design will result in a few sharp corners. Use an orbital sander or belt sander on (or hand sand if you prefer) any corner you anticipate will cause discomfort or injuries. Then touch every edge with a cursory sanding. Wipe everything with a damp cloth to remove remaining sawdust and then let it dry before painting the loft.

To protect the bed frame, paint the entire loft with primer paint (or stain or polyurethane if you prefer.) Depending on how thick the primer is, you may need several coats of paint. Put down a drop cloth and prop the loft up on blocks so that when you paint the loft it doesn’t damage or stick to the floor.

We hope that with every new decoration/doodle/drawing our daughter adds to the loft, the more she feels like this loft is hers. This white primer is an excellent blank canvas! It'll be great.