For the Latest Bird Watching News, Hot Birding Spots, Tips & More, Subscribe to
Our Free Newsletter: The Birder Alert!
Making Bird Houses
Making bird houses is a great activity for the entire family. It provides birds
with additional nesting opportunities and gives you unparalleled bird watching
There are a tremendous variety of nest boxes designs. They come in all
sizes and materials.
But let's think a minute about why we want to build a bird house and what we hope
Reasons for Building a Bird House
Increase Potential Breeding Sites for Cavity Nesting Species
Attract Target Species to Your Property
Goals for Improving a Nest Box
Improve Nest Box Occupation by Target Species
Improve Fledging Success of Nestlings
Reduce or Eliminate Problems from Predators
Reduce or Eliminate Nesting Attempts by House Sparrows or Starlings
Improve Longevity of the Nestbox
Improve access for Monitoring and Cleaning of the Nest Box
How To Build a Bird House Video
Making Bird Houses - Construction Tips:
Size of Nest Box Matters
If the box is too small, the birds will not use it or it may become so crowded
as the young grow. They may not be injured, but a crowded box is hard for
the adults to keep clean and it is more difficult for chicks to stay cool.
It is possible that young are forced to fledge prematurely.
Some believe that larger boxes help the birds exercise more, so they are more
capable of flying when they fledge.
If the box is too large, the birds may not use it because it is too vulnerable
to predators or it may attract too much attention or be difficult to support.
Bird House Roof
Every nest box needs a roof (though many natural cavities are open on top). Our
choices are fairly simple. Flat or a sloping; overhang or flush.
It appears that in most cases (there are lots of nest box designs) that 1
inch overlap on the sides and 2 inch overlap in the front is adequate for
protecting the occupants from the elements (rain) and increasing the boxes longevity
by keeping the box dry.
Another main function of the roof is to provide shade for nest boxes that are
exposed to the Sun, especially in warm climates.
So the roof should be sloped to help water runoff (as close to 45 degrees as
possible), and it should be overlapped to let water drip away from the box and
to provide more shade.
If you plan to place your box in the open (bluebirds for example) in a warm
area, you should consider a double roof to keep the box cooler. The two
roofs should be spaced to allow air to circulate between them. It has also
been suggested that a second side wall be added to also shade the west side of
Front of Nest Box Most nest box plans have a perpendicular face, but recently, several designs
have a sloping front. The advantages are several. 1 - easier for
young to escape from the box and 2 - protects entrance holes better from wind
Disadvantages are also several. 1 difficult to mark and cut and 2 - increases
What kind of Hole for the Nest Box? Round, Oval or Slot? One hole or
Believe it or not, several bird house designs have more than one hole.
Advantages? Both adults can feed young at the same time - one adult doesn't have
to waste energy & time flying around.
A second hole may prevent the strongest chick from dominating access at the
Also, if predators or house sparrows get in the nest, at least the adults
have a chance to escape through the second hole.
If ventilation is an issue, the second hole also acts as a big vent.
Well, at least I have convinced myself... the next box I build or modify will
have two entrance holes.
Disadvantages - May allow easier access by predators and weather (rain).
Some of the research seems to indicate that Bluebirds are attracted to the oval hole
(more than the Peterson box shape).
There are conflicting data about the slot hole design and access for house sparrows.
Some say the slot entrance discourages house sparrows and others have found that
house sparrows readily use them.
Bird House Building Materials
Wood The building materials don't necessarily have to be wood. I guess we could
use the recycled plastic material that is being used for decks and fences.
Nest boxes can also be made from PVC pipe or plastic buckets, but those are
different plans to be covered later.
What kind of wood?
If you have access to redwood or cypress or even cedar, that's great.
Those types of wood will last a long time, but they can be expensive.
Hardwoods will last longer than soft woods, but they can also be expensive.
Treated or untreated wood for Nest Boxes?
Treated wood (softwood) will last longer. But is treated wood safe to use
for bird houses? The EPA website says treated wood is safe to use in
vegetable gardens and on picnic tables, but it is not safe to use on cutting
boards, counter tops or bee hives.
CCA treated (Wolmanized). This material was
stopped from use in residential
construction in 2003, Canada.
I have seen web sites that claim treated wood releases "dangerous fumes" and
should not be used when making bird houses. They do not cite the source of this
Another website says that only untreated wood should be used in case the birds
"gnaw" on the wood. Except for parrots, birds are not generally known for
gnawing, but they do peck at the wood (That is how woodpeckers and chickadees
excavate their nest cavities).
The Purple Martin Conservation Organization recommends: "Only untreated wood (no
pressure-treated wood, no chemically-treated wood, etc.)" when making bird
Since birds are well known to be very sensitive to environmental pollutants
(remember the canary in the coal mine?), let's not take any chances. Only
use untreated wood.
Nest Boxes can be made from solid wood stock, plywood, bark slabs or solid
Many of the nest boxes I built in the past were made of plywood, because I
always had scraps of plywood handy.
Many plans recommend using plywood (exterior grade plywood) and some even
preserve the wood with spar varnish.
Nest boxes can also be built by using exterior slabs (slab lumber) that still
have the outside tree bark when the tree is sawn up to make lumber.
Solid logs can also be hollowed when making bird houses. I have done this by first splitting the
log, then hollowing out each side, drilling an entrance hole, then joining the
two halves back together with wood glue and screws.
Thick or thin wood stock for Nest Box?
When making bird houses, the thickness of the stock determines the thermal insulation
of the next box. It can get cold in the Spring and always gets hot in the Summer sun.
A one inch thick box will protect eggs and young from temperature extremes more
than a half-inch thick box. This doesn't mean that a half-inch box is
useless (I have a half-inch thick blue-bird box that fledges 3 or 4 tree swallows
Thicker stock is also heavier and more expensive than thinner stock, but it will
also create a sturdier box if constructed properly.
Any stock thickness between one-half in up to one inch should be acceptable for
a nest box. If your area is notorious for cold nights in the Spring or if
your nest box is to be placed in full sun (with no shade), you may want to go
with thicker stock or to provide more shade, use two layers of thin stock with
spacers between them for roof and west side.
Smooth or Rough Wood for Nest Box?
We all like the feel of a smooth sanded wood, but the truth is, the birds
benefit from a rough surface. A rough surface helps the adults to cling to
the side of the box when bringing the nesting material and when feeding the
young. It also helps the young scramble out of the box when it is time to
go. (Many Wood Duck plans recommend that a "ladder" be made from welded
wire or scored into the wood).
Perch or no Perch on Nest Box?
If rough wood helps the birds to "hang on", wouldn't it help to add a perch?
It probably would... but it also helps cats, raccoons, snakes and other nest
predators to hang on to the perch while they fish around inside for
something to eat.
Other Construction Tips when Making Bird Houses:
Use large wood shavings or chips but no straw or sawdust.
American Kestrels will use nest boxes, but do not build a nest. They
will scrape together the loose
material in the bottom of a cavity.
Rough up or score the wood inside the hole so the chicks can scramble out.
Why let another breeding season go by and you still haven't built a box.
Free Bird House Plans
What Species of Bird do you want to attract to your nest box?