I had my woodworking shop in the basement storage room, but people were always peeking in trying to see my half finished creations. I decided to make the room a bit less conspicuous.

It took me ~12 hours of work spread over a couple weekends. Most of the time was actually me trying to figure out the lock.

You will need:
roughly 30 linear feet of wood (between 8-12 inches wide S4S)
screws or dowels to hold things together
a mitre saw
stain or paint
wheels
~17 feet of moulding
magnetic Lock
power supply for lock
2 exit buttons for lock

Step 1: First Take Off Door

Remove the hinges from the door and set it aside. You will need the hinges later, unless you plan to buy new ones.

Step 2: Measure Your Door

This will give you the exact dimensions you will need to build the book case. Mine was 71.75 Inches by 30.25.

*I ended up adding a quarter inch to the height to hide the space at the bottom which is normally present for most normal doors.

Step 3: Cut Wood to Correct Lengths

You will need:

2 lengths the height of your original door
5 lengths the width of your door (minus the thickness of the wood)
10 1" strips
1 4" X width of door strip (to conceal the wheels)
3 blocks the size of your hinges

*I suggest S4S wood so you do not need to plain it

I cut:
2 72" boards (12" width by .75" thick poplar)
5 28" boards
10 1" strips
1 4"X28" Strip
3 2"X 3" blocks

Step 4: Measure and Attach 1"strips

These strips hold up the individual shelves so they need to be placed even heights on your long boards. Any height will do as long as they are even.

I screwed these strips to each side keeping them level. (You can use any attachment method you would like) Mine are every 18" and I removed them later.

Step 5: Attach Top and Bottom Shelves for Structure, Then Add the Rest

You will probably need a friend for this part, unless you want to play the balancing act like I did. (I have no friends)

Rest the short board directly on the guides you screwed in during the last step, and screw through the fact of the long board into the end of the short board. I put three screws on each side of each shelf (You can use dowels or any other method you'd like).

Always start with the top and bottom, that way you will be able to stand the shelf for the rest of the project.

The top is flush to the top of the door, the bottom should be 4" from the bottom. You will use this space for the wheels. (Yes this thing rolls).

Step 6: Add the Rest of the Shelves So This Looks Like a Book Shelf

Same instructions as the last step. (Don't make me repeat myself)

Step 7: Screw in Your Wheels

I used these wheels, but any similar wheel will work:
http://www.amazon.com/gp/product/B0000DD1ED/ref=oh_details_o00_s00_i00?ie=UTF8&psc=1

You will screw these directly into the bottom shelf. These hold the weight of books and you will reduce the stress on your door frame. I just spread them out evenly across the bottom. I needed to add some height with scrap wood.

Step 8: Hide Your Wheels

Attach the 4" strip to the front of the bookcase to hide the wheels. This is done in the same fashion as the shelves, but with the face of the wood facing where people would see it.

Step 9: Add Hinges

Screw your 3 hinge blocks to the side of the shelf at the exact height of the pre cut hinges. This adds space so the door can swing.

Screw the hinges to the blocks in a secure fashion re-using the screws from the original door,

Stand your shelf up and then attach the hinges where you removed them. Since I was alone, I added broke the hinges apart so I only had to line up the pin.

Step 10: Cover the Massive Space Between the Shelves

I used a board of 1/4" plywood to create the backing. I cut it to the dimension of the door and tacked it on. No you cannot see through the door.

Step 11: Add Moulding

You will have gap on the hinge side of the door. I bought some cheap molding and tacked it up to cover the space. This also accounts for any places you measured poorly.

Step 12: Make Sure Your Door Opens and Shuts...

or else it isn't worth it. Sand down any necessary areas to make sure it works.

Step 13: Pick Out a Lock

I used a 300lb magnetic lock that I found on ebay. They are all over the place and some come in kits like this one:
http://www.ebay.com/itm/Complete-Magnetic-Lock-Locks-Kit-w-1200-lb-Hold-Force-/120486689920?pt=LH_DefaultDomain_0&hash=item1c0d90fc80

Any one will do, but beware there are almost no instructions in the box.

I went with a magnetic lock, where the magnet is attached to the shelf
a ZL bracket (which is attached to the wall and hold a hunk of metal to add force)
A power supply (Hardwired)
2 exit buttons (One hidden on the shelf, one on the inside wall to let me out)

Step 14: Attach the Lock

Attach the electric magnet to the wall next to your door. This has power so it is easier to keep that in one place. Wire your power supply right near it for easy attachment.

Screw the rest of the bracket to the side of the door (with the hunk of metal). You will need to align this with precision to make sure the door looks flush when closed.

Step 15: Add the Exit Buttons

I mounted one exit button in a gang box next to the door for easy access. It came with a plate and was simple to install.

The other is wired over the top of the door frame and down the hinge side of the door. You then drill a hole in the plywood to run the wire to where you hide it.

I used my friend's math trophy he earned in 7th grade. He is mad I stole it.