Although we live in a spacious 3+1 bedroom home, all the bedrooms are currently occupied. Meaning that, when we have company come visit, we don't have a guest room for them to stay. After a lot of consideration, we decided that we could convert our living room into an on demand spare bedroom. So we suited the room with a set of removable doors for privacy but we weren't sure what to do for a spare bed.

Our options were Blowup mattress, a pull out sofa, a murphy bed or a lesser known fold out bed. It became obvious to us pretty quickly that a blow up mattress lacks any luxury and looks like an afterthought. A pull out sofa just wasn't in our budget, plus we already had a nice sofa that we didn't want to part with. We had a murphy bed in our previous home, and although it was practical in that environment, it just wouldn't fit in our living room the way all of our furniture was arranged. That's when we googled the internet for alternative solutions and stumbled upon fold out beds.

The idea behind a fold out bed is just as the name implies. When folded out, the primary function is a bed frame, but when folded in, it can compact in size and function as a bench or other type of furniture.

Supplies

Milled Lumber - kiln dried:

(4) - 1"x10"x8'
(2) - 1"x8"x8'
(2) - 1"x6"x8'
(2) - 1"x2"x8'
(13) - 1"x3"x8'

Structural Lumber:

(2) - 2"x12"x8'
(2) - Ø1 1/4" or Ø1 3/8" x 4' Long Dowel

Hardware:

(7) - Everbilt 3-1/4-inch Chest Latch Satin Nickel
(16) - Everbilt 6-inch Heavy Duty Strap Hinge, Zinc Plated
(4) - Everbilt 3-in Trap Door Ring in Zinc
(8) - Everbilt 3/4" Corner Brace, Zinc-Plated, 4pc
(100 pack) - #8 x 5/8" wood screws

Paint

Wood Glue

Tools:

Table Saw
Miter Saw
Plunge Router
Palm Sander
Drill
Clamps
Measuring Tape
Air Compressor
Brad Nailer
biscuit jointer to dowel hole jig
Pocket hole jig

Step 1: Develop Plans

I'm a draftsman by trade, so I had access to AutoCAD and was able to draw this project out on the Computer, but this could be figured out using hand sketches and calculations too.

This project was intended to utilize a Queen Size Mattress (60"x80"), so all my dimensions are based on this reference size. If you decide to use a different mattress size, you'll need to make adjustments to some of the Cut-List items.

I also added a 1/2" clearance gap all around the mattress to ensure it would fit within the bed frame. That pretty much locks in the plan view; for the elevation (height), that's really up to user preference, so feel free to adjust this value as you see fit.

Step 2: Develop Cutlist

I've provided a few images (above) of my cut-list. I did make some design changes and attempted to update the cut-list, but just be aware that it may still contain some legacy data that may be incorrect, so use it at your own risk.

Once you have a developed plan, based on the mattress size you intend to use, you can start working backwards to determine the lumber sizes you want to use. Be aware that a milled lumber sizes aren't actual dimensions. For example, a 1x10 is not 1" thick by 10" wide, rather, it's actually 3/4" thick by 9 1/4" wide. The lengths are accurate though, so an 8 foot long board is actually 8 feet long.

Notice that Item numbers (4) and (5) are staggered from the left side vs the right side of the frame. This is intentionally done, to allow the hinged side panels to bypass each other as the bed collapses into its folded up arrangement.

Step 3: Purchase and Cut Materials

Once your cut-list is complete, go to your local lumber mill or hardware store and acquire the material.

Most pieces can be cut 90° to create butt joints, but I mitered all the (item # 1) boards along the long length at 45° to form the joint above - these form the (4) corner posts of the frame.

Step 4: Assemble

Wood assembly is pretty straight forward. Collect all your cut items and begin wood gluing the (4) corner posts. It's critical that both boards (Items #1) form a 90° angle at each corner. Secure the miter joint with a couple of brad nails in both directions. Allow the corner posts some time to dry.

When the (4) corner posts are dry, you're ready to assemble the head board and the foot board. Using a biscuit jointer or dowel hole jig, prepare the joint between item numbers (1) and (2). Apply wood glue to the butt joint and insert the biscuit or dowels. Repeat the process for the opposite end. Locate item number (3) and prepare some pocket holes to the underside on three sides (2 short sides, 1 long side), glue and screw the board to this assembly. and clamp together and allow to dry. This will form the head board end of the frame. Repeat this process to make a duplicate assembly for the foot board end of the frame.

Laminate both boards [item (9)] to form the headboard/bench seat. I used a few dowels and few pocket holes to secure the butt joint together.

With the Head board and foot boards assembled, the rest of the assembly regards the hinged connections for the Side Boards. Lay down items (4) and (5) such that they butt up against each others ends. Connect two hinges (1 on top, 1 on bottom) centered along the butt joint of the two boards. Repeat this process for the opposite side. Note that Items (4) and (5) are to be staggered from the left side to right side. In other words, they should not mirror each other.

Now connect (2) hinges to each end of items (4) and (5), only this time, offset the hinge so the pins are offset from the end of the board by 1" inch.

You're now able to connect the Head board and Foot board assembly to the Side Board Assemblies.

Lay down items (6) and (6) such that they butt up against each others ends. Connect two hinges (1 on top, 1 on bottom) centered along the butt joint of the two boards. This will be used as the Center Board Assembly. I used a couple pieces of left over 1x2 to sandwich the Center Board Assembly and fastened them to the head board and the Foot board to ensure the Center Board Assembly would stay supported upright. This Center Board should be able to slip in and out of the frame while folding it in or out. It will fold up and stow away into the bench when in the Bench position.

Screw items (7) and (8) to both Side Board Assemblies. These will form the rails that the slats will rest on.

Laydown the (13) 1x3 slats.

Using (2) hinges, fasten the headboard/bench seat from earlier to the head end of the frame. Install (2) trap door rings to the bench seat. I router'd out some material so they would sit flush. Orientation is important, I like them positioned when the bench seat is in the upright position, forming the headboard, the ring falls down out of the seated position. I now run (2) pieces of dowel vertically into the ring and align them so they are plumb and mark the bottom of the head board to locate where the (2) bottom trap door rings need to go. Fasten the lower trap door rings to the head board.

We're now going to fold up the bed into the bench position. Remove the (13) 1x3 slats and Center Board and temporarily set aside. Gently push in the center of the Side Boards you'll notice the head board and foot board ends begin to close in on each other. Continue pushing the foot board until the two side boards are nearly touching. If assembled correctly, one side board should approach the head end while the other approaches the foot end. Continue pushing together until the head board and foot board are touching.

Fasten (2) chest latches per side as to lock the head board to the foot board.

Remove the Dowels from the trap door rings, place the dowels into the bench. You can place all the slats and center board into the bench too. Lower the bench seat.

Step 5: Convert From Box to Bed

When I originally made this, I used two 1x10 flaps to form the bench seat, but was disappointed with its performance as a seat. It was very flimsy. So I upgraded to (2) laminated 2x12 and this formed an esthetically pleasing head board. My pictures above show both options.

To convert back to a bed:

Lift the bench seat and install the two Dowels to Lock the Head Board into place.
Remove the slats and center board from inside the bench and set aside.
Unlatch the (4) chest latches that connect the head board to the foot board.
Pull and extend the foot board to unfold the bed frame.
Unfold and install the Center Board.
Laydown the (13) slats.
Plop on a mattress.

Step 6: Modifications

I wasn't very confident about the strength of the hinges, so I added (3) fold down legs to the (2) side boards and the center board. I'm 300lbs and have slept on this arrangement and can confidently say its structurally sound.

I also added chest latches opposite of the center hinges to the (2) side boards and the center board just to ensure they don't buckle.