How to Build a NABS Birdhouse

The North American Bluebird Society's website has some excellent plans for building nesting boxes for Eastern or Western Bluebirds. Doing a project for a park district in my area, I've built several birdhouses from them. However, I've found that it can be a bit difficult -- especially at first -- to build things strictly from their diagrams, without much written instruction or tips on how to do certain parts. I thought it might be helpful to make an instructable to provide just that. So here it is, for all you bluebird lovers out there!

To learn a little more about bluebirds, check out my website here~!

To make one nesting box, you'll need ...

Materials:

• 1" x 6" rough-cut cedar board (4' long -- for the front, back, sides, and bottom)
• 1" x 8" or 1" x 10" rough-cut cedar board (10 1/2" long -- for the roof)
• 1 3/4" galvanized screws or nails (11 -- for assembly and pivot)
• 2-3" duplex or standard nail (1 -- to secure the swinging side)

Notes:

• A 1" x 6" is actually 5/8" - 3/4" thick by 5 1/2" wide, for measuring purposes
• For the roof, the 1" x 10" just offers a slightly larger overhang
• You need a 10 1/2" long piece for the roof for each birdhouse, so buy accordingly -- you'll probably end up buying a longer board
• I used #6 screws because they're thin and make things a bit easier
• Wood that's smooth on one side and rough on the other is ideal, but entirely smooth or entirely rough wood can work too

Tools:

Disclaimer: These are just the tools that I had and used; similar tools that function the same way can be substituted. Please make sure to get an adult to help, educate, and supervise when using power tools!

• Compound Miter Saw
• Backsaw
• Coping saw (not pictured)
• Cordless drill/driver
• Detail sander
• Sanding block
• Square
• Tape measure
• Clamp
• Hole saw (1 1/2")
• Phillips screwdriver
• Drill bits (One appropriate for the duplex nail, the other for the galvanized screws)
• Eye and ear protection
• Gloves
• Pen/pencil/sharpie

Next, you'll use the square, a pencil, and a sharpie (or other dark, permanent marker) to measure out the front, back, sides, and bottom on the 1" x 6" x 4' board.

Before you start ...

• If you have wood that's only rough on one side, make sure the rough side is facing up!
• My measurements aren't quite the same as the ones in the NABS diagram. I added 1/8" in the appropriate places to allow for the kerf of the saw blade. (That's a fancy word for the wood that's lost because the blade can only be so thin)

And there's one tricky thing -- you need to measure the thickness and width of the 1" x 6" x 4' board, because it can vary, and this determines how long the bottom piece needs to be. If you view the diagram above, you'll see why - the bottom piece needs to fit snugly in between the two side pieces once they're attached to the back. To find the proper length for the bottom piece, measure the width and thickness of the boards; the bottom piece's length = board width - 2 * board thickness. In my case, for example, the board width was 5 1/2" and the board thickness was 3/4", so the length of the bottom piece was 5 1/2" - 2 * 3/4 = exactly 4".

Once you've figured out the length of the bottom piece, measure and mark it on your board using the measuring tape and a pencil or pen. I drew a line across the whole board so it was easier to see, but you can just make a small notch. The appropriate lengths can be found below; just measure and mark them in order and you'll be ready to move on to the next step!

All of these measurements are along the bottom of the board (the measurements on the top of the board are slightly different for the angled pieces; see picture)

• ~4"
• 9 3/8"
• ~2" (note that the angle on the other side is ~20 degrees; just measure 10 3/8" on the top of the board in the appropriate places, as shown in diagram, if you don't want to worry about measuring the angle)
• 9 3/8"
• 9 1/2"
• ~ 1' 1 3/4" (just whatever's left over)

Please remember that power tools can be dangerous; an adult should either do this for you, or teach you how and supervise you. Always be careful!

First, the basic cuts that don't require any angles or bevels. I used a compound miter saw for this. Make sure to cut as close to the original measurements as possible!

There are only two cuts you will be making right now; the other cuts all have special angles or beveling, which will be explained in the next steps. Look at the images above to see the two cuts you'll make with normal settings.

Please remember that power tools can be dangerous; an adult should either do this for you, or teach you how and supervise you. Always be careful!

Next, you'll make two angled cuts, which are necessary so that the sloping roof of the birdhouse can fit on properly. Set the saw on a 10 degree angle, and make the first cut as shown. Then flip the board over and make the second one. You'll be left with a small triangle of scrap wood, which I just threw out, but if you want to find a way to reuse it, go you!

Please remember that power tools can be dangerous; an adult should either do this for you, or teach you how and supervise you. Always be careful!

Last but not least, you have to make a beveled cut. This is for the front and back pieces, and once again, it's so that the roof can fit on properly. Set the saw on a 10 degree bevel, make sure you're cutting from the top left to the bottom right, and confirm that the shorter piece is on the right. Afterwards, make sure you set the bevel back to 0 degrees!

Once you've done this, you're all done cutting. Make sure you've done it all correctly, and then you're ready to move onto assembling the birdhouse!

For this step, you'll be cutting the hole that'll serve as an entrance for the bluebirds! This should be cut on the front piece, and although I did it first here, you can also do it once the birdhouse is fully assembled, using the same steps. (In that case, skip onto the next step and then come back here later for the proper measurements and all!)

You'll need a 1 1/2" hole saw. It needs to be exactly that size -- otherwise it'll be too small for the bluebirds to get in, or big enough to let other birds (and predators) in! Measure to the middle of the board, and then up 7 1/4" up. (6 1/2" + half the diameter of the hole to get the proper center point) Make a dark mark here; this is where the center of the hole will be. Next, clamp your front piece onto a workbench or other stable structure with a scrap piece underneath so the holesaw won't drill a hole in your bench/table. Make sure it's clamped securely or the wood will spin around when you try to drill it!

Position the holesaw drill bit on the mark you made earlier, make sure you're perpendicular to the board, and then drill until you're all the way through! Don't worry if you have any rough edges, we'll clean those up later.

Next, you'll be cutting the corners off your bottom piece. This is to allow for drainage of any buildup of water that happens to get in. There aren't any specific measurements for this one; I went for a bit larger than 1/4" on each side. Just mark where you'll be cutting and try to have them all around even. Then, using a coping saw, cut the corners off! I went in with a detail sander next and smoothed up the rough edges.

Now, take the back piece and the right side. Find the top of the back (which has the beveled cut) and on the smooth side (which will be the outside) mark a spot 2" down from the top and and half the board's thickness in from the right side (You measured this earlier; it was 3/8" for our 3/4" thick board). Then make the same measurement for the left side; you can use a square tool or just measure 2" down and half the board's thickness in, again. Next comes a trickier part -- you need to clamp the right side board to the backboard so you can begin assembly. The smooth side of the back and right board should face out. Line up the top of the right board (which is the angled cut) with the top of the back board (which is the beveled cut), but then slide it down about 1/4" to leave room for ventilation.

Now use your drill to drill a hole on the spot you marked (if you have a countersink, it's nice to countersink it as well) and then screw a screw into the hole you just drilled.

To finish this side off, find where the bottom of the right side meets the back, then on the back, go in 1/2 the thickness of your board (3/8" for us) and up 1/4" + 1/2 the thickness of your board (coming out to 5/8" for us.) Again, drill and screw, and voila! You're done attaching the right side and the back, and you can unclamp the pieces.

Position the bottom piece so it's 1/4" up from the bottom of the right side board. It should be wedged securely against the back and the right board. Then mark a spot halfway across the right side board and 1/4" + 1/2 the thickness of the board up from the bottom of the right board (1/4 + 3/8 = 5/8 in our case). Then drill the pilot hole and screw in the screw (Note: I used the left side to keep the bottom piece from falling so I could drill vertically; see picture). Now you've attached the bottom to the right side!

Next you need to attach the bottom piece to the back piece. If you've measured everything correctly, you should be able to use a square and measure halfway across the back piece to make this mark. Otherwise, just measure up appropriately and then measure halfway across. Now drill the pilot hole and screw in the screw and you're on to the next step!

Your next step is to attach the left side, which will swing open to allow you to clean out the birdhouse, to the back piece. Start by lining the left piece up on the back, and then sliding it down ~1/4-3/8" to allow for ventilation and to make it easier for the side to pivot.

The attachment process is really simple, once again; just use the square tool across the back, lining it up with the top screw attaching the right side to the back. Make a mark half the board's thickness in from the edge, drill a pilot hole, and screw in a screw!

NOTE: You don't need to screw this one too tightly -- it'll need to pivot later.

Position the front piece so the top edge is ~1/4" higher than the sides (Again, this is for ventilation and to aid the swinging side). Start by attaching the top of the front to the right side, using the square to line up and mark the position as shown in the pictures. Then drill a pilot hole and screw in a screw.

Now you'll attach the bottom of the front to the right side! Once again, line up your square tool with a screw on the right side/back, make a mark as shown in the pictures, and then drill a hole and put in a screw. Don't worry, you're almost done!

Next, you'll attach the front to the bottom side. Measure halfway across the bottom, from the screw on the right side as shown in the picture, and you know the drill from there -- drill a pilot hole and screw in a screw.

Lastly, you'll attached the top of the front to the left, swinging side (we'll deal with the bottom of the swinging side next step -- if we just screwed that in normally it wouldn't pivot!). Carefully use the square to mark a spot on the front that lines up with the screw on the back. If they aren't very closely aligned, the left side won't pivot properly, so don't rush this step! Once you've found the spot, take a minute to admire my nails, and then measure in half the board thickness, drill, and screw.

After you're done, test to make sure the left side swings properly! If not, you may need to take a screwdriver and loosen the screws bit by bit until it does.

Now set the roof on smooth side out. The top of the roof should overhang the back slightly, and the bottom should overhang the front -- no precise measurements, but just make sure it overhangs them both and hangs out equally over the two sides.

Next, measure halfway across the top of the roof and mark a spot in from the back edge enough so that when you or a helper looks from the side, the screw seems like it will go about halfway through the back board. Drill a hole and put in a screw!

Your last screw will be attaching the roof to the front. As shown in the picture, measure back to front to get an approximate measure, then use that to mark a spot that's lined up with the other screw you already put in the roof. Again, look from the side to make sure that it seems to be in about the right place. Then drill and screw and you're nearly done!

You're so close to being finished! Just two final touches ...

• Drill an angled hole through the front and swinging side so you can loosely slip a nail in to hold the swinging side shut. This doesn't need to be at any specific height, just make sure it's high enough so that the hole won't be going through the bottom of the board, and not so deep that you won't be able to pull out the nail. Of course, it should be half your board's thickness in from the edge.

• Your final step is making 3 score marks just under the hole, which I did using the backsaw. These should NOT be very deep, you're not trying to slice through the birdhouse here! These are so that the birds can perch on the outside of the birdhouse more easily. You might expect a birdhouse to have a dowel-like perpendicular stick for a perch, but the score marks work just as well for little bluebirds and are harder for predators to use to gain access to the birdhouse!

Congrats! You've built a birdhouse!

All you need to do now is mount it. Check out the NABS website (linked in the intro) for some useful tips. In general though, putting it on a solid metal pole is one of the best options -- metal poles are slick and difficult for snakes and other predators to climb up, are cheaper and easier to install than wood, and doesn't involve potentially damaging a tree from attaching to branches or treetrunks.

One last note -- don't paint your birdhouse! It may seem tempting to give it a little color, but these colors can attract predators, mess up internal temperature, or poison baby birds that peck off scraps of paint.

Thank you for reading my Instructable, hope it was helpful! I'd love to see a picture of your finished project!