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 opportunities. 

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 to accomplish.

Reasons for building a Nest Box

• Increase potential breeding sites for target species

• Attract target species to your property

• Educational opportunity

• Photography

Goals for improving Nest Box

• Improve Nest Box occupation by target species

• Improve Fledging Success of nestlings

• Reduce or eliminate problems from predators
• Improve longevity of the nest box
• Improve access for nest checks and cleaning

Making Bird Houses - Construction Tips:

Size 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.

What Species do you want to attract?

Here is a Bird House Dimensions Chart for 34 species.

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 and increasing the boxes longevity.

Front
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 and rain.

Disadvantages are also several. 1 difficult to mark and cut and 2 - increases scrap wood.

One hole or two? Round, Oval or Slot?
Believe it or not, several bird house designs have more than one hole.

Advantage? 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 entrance hole.

Disadvantage - Allows easier access by predators and weather.

New research seems to indicate that Bluebirds are attracted to the oval hole (more than the Peterson box shape)

The slot hole design appears to be easier for House Sparrows to access.

Bird Houses Building Materials:

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?
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.

US EPA Fact Sheet

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 information.

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 houses.

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.

Solid stock, plywood, bark slabs or solid logs?
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.  But isn't exterior plywood treated?  Didn't we just decide to use untreated wood only?  Many people have been using plywood for years without noticing problems.

So what to do?  If you have untreated, solid stock, use that to build the nest box.  If the choice is build the nest box from plywood scraps today, or build from solid stock later, I say build the house out of plywood now.  Why let another breeding season go by and you still haven't built a box.  I will continue to research on exterior plywood.

Nest boxes can also be built by using exterior slabs (bark) that are cut away of bark that

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 stock?
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 fledged 3 tree swallows last summer)

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.

Smooth or rough?
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?
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:

• Rough wood shavings but no straw or sawdust.
• American Kestrels do not build a nest, but will scrape together the loose material in the bottom of a cavity.
• Rough up the wood inside the hole so the chicks can scramble out.

We will be expanding our "Making Bird Houses" page as further our research as well adding pages for specific bird house plans.

Enjoy making bird houses and the birds that make them their home!

Here are some bird house plans sold on eBay both in digital delivery and CD formats:

Choose the appropriate link below for specific bird house plans:

All Bird House Plans

Bluebird House Plans

Purple Martin Bird House Plans

Robin & Phoebe Bird House Plans   

American Kestrel Nest Box Plans

Wren House Plans

Wooden Bird Houses

Bird House Dimensions Chart

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