There are a lot of different bluebird nest box designs out there and choosing can be very difficult. Here, we outline all the different styles – regular wooden boxes, recycled plastic nest boxes, Peterson nest boxes, Gilbertson nest boxes and so on.
Ultimately, when choosing a bluebird nest box, there are a few important factors to consider.
For eastern bluebirds, wooden nest boxes with an entry hole size of 1.5 inches, dimensions of at least 9 x 4.5 x 4.5 inches (though larger is better), good drainage and good ventilation are a great start. Other features may help with monitoring, preventing overheating or protection.
Features that make the best eastern bluebird houses include dimensions of at least 9”x4.5”x4.5,” a 1.5-inch entry hole, light colored wood, side or front-opening for monitoring access, drain vents and side vent holes. But there are other specifications to look for when trying to accomplish something specific.
- Access for monitoring and cleaning – preferably a side or front opening instead of a top opening.
- Drain vents at the bottom of the nest box.
- A Bluebird house’s hole size should be: 1.5-inch hole for eastern and 1-9/16-inch hole for western and mountain bluebirds, the latter working universally for all 3 species.
- General bluebird nest box dimensions should be: at least 9”x4.5”x4.5” where the base of the floor is a 4.5”x4.5” and the walls are about 9” high. This will vary based on different types of nest boxes. Slightly taller, wider boxes help keep boxes cooler on hot days and provide room for both parents to tend to the nest at once.
Often, you’ll find an eastern bluebird house with some, but not all of these features. Fortunately, depending on what needs to be adjusted, it can be very easy to modify a bluebird nest box.
For instance, this box had a lot of features ideal for eastern bluebirds. However, it had a dark top. The dark color of the top can be harmful to bluebird nestlings and eggs on very hot summer days because it can cause the box to easily overheat. But that can easily be fixed with white water-based paint.
*Note: Many trail managers regard this specific nest box to still be too small (our use for it was a decoy box since it was super cheap).
Retail nest boxes built according to the North American Bluebird Society, Gilbertson PVC boxes, Gilwood nest boxes, and Peterson nest boxes are among the most common nest boxes for eastern bluebirds.
Having several options is nice, but it can make it very difficult to choose. In this section, we’ll explore these different nest boxes and explain the pros and cons.
Keep in mind something very important about bluebird houses: Decorative bird houses are not bluebird houses and can create problems with conservation. Do not put these out unless the holes are plugged up.
Watch the Video:
Retail wooden bluebird nest boxes
Retail nest boxes are the type of nest boxes you’ll find at a wildbird store, hardware store, farm stores or on Amazon. We carry a few that meet our requirements of safety and conservation.
These nest boxes come in a lot of different varieties and with several options.
When looking at retail nest boxes, here are some things to look out for that are ideal (or not ideal) for eastern bluebirds:
Things to look for in a retail wooden nest box
- The wood is a light color – minimizes heat.
- Wood thickness is at least .75 inches or more (better insulation from heat or cold).
- The entry hole is 1.5-inches.
- The bottom of the box has drain holes.
- There is access for monitoring and cleaning.
- There are grooves inside just beneath the entry hole (sort of like a ladder) to help fledglings.
- The roof provides adequate shade and prevents water from entering.
- There are vent holes at the top sides – especially important if you have very hot summers.
- It is especially reassuring to see a label that the nest box is approved by the North American Bluebird Society (NABS) or was built according to Bluebird Society plans.
- Bonus: Some have heat shields – these nest boxes are great if they’re large enough
- Bonus: Some nest boxes have 2 side openings, one with a clear acrylic plate strictly for monitoring
Things to avoid when shopping for a nest box:
- Copper top put over the roof (up for debate). Heat is a concern because birds like to perch on top of the box. It is also unclear, but possible heat will transfer into the nest box.
- Nest boxes with a darker top.
- Dark colored boxes or dark painted boxes because that will transfer a lot of heat.
- Boxes that are too small (8.5”x4”x4” or smaller for example)
- Nest boxes that do not have access for cleaning and monitoring.
- Decorative boxes that do not allow proper monitoring, maintenance, protection and cleaning.
- Top access ports should be avoided (with the exception of a Gilbertson box). Look for side or front access since that is easier for cleaning and better monitoring (check out our article that explains in more detail why a side or front opening box is better than a top opening box)
Other considerations of wooden nest boxes
Aside from the basic specifications mentioned, you want to make sure the wood is at least .75 inches thick. The thicker, the better because it insulates during cold weather and minimizes heat penetration during hot weather.
Pine is a good wood material. And depending on overall climate and weather, it will hold up for a number of years. Painting your box with a water-based paint may improve durability. However, the only color we recommend painting is white or very very light colors. Never reds or blacks or dark colors because that will contribute to deadly heat penetration.
Cedar is a wood known for its long lasting durability in all sorts of weather conditions. Certainly, these nest boxes will provide you with more years, but are often more expensive.
Best value bluebird nest boxes for those starting out
The best value bluebird nest box if you’re just starting out is the Woodlink BB3 model. It’s very affordable and easy to find on Amazon. The Woodlink BB3* model has almost everything needed to take care of your bluebirds.
The downside to the BB3 model, however, is that they’ve changed the design. There are no longer grooves for fledglings. These are easy fixes. You can use hardware wire to work as a little ladder for the nestlings. You may be able to easily chisel or scrape line grooves as well.
Woodlink BB3 specs
- Entry hole: 1-9/16 inches. 6 inches from entry hole to floor.
- Material: Constructed of reforested, kiln dried, inland red cedar
- Access: Front opening for easy cleaning and viewing
- Venting: Side vent holes and drainage area near opening.
- Floor dimensions: ~ 4-⅜ x4-⅜
- Kerf: May no longer be present in new design
Order from Nest Hollow:
Or find it on Amazon*
Also, for a complete guide on actually attracting bluebirds and whether it’s possible in your location, check out our resource.
Recycled plastic nest boxes
Many bird stores carry nest boxes made out of recycled plastic. And in terms of conservation, this is a great idea. It promotes sustainability and provides decent shelter for native birds.
The question is whether native birds prefer these over wooden nest boxes or vice versa, or is it just the same?
When it comes to recycled plastic nest boxes and bird preference, it really depends on the birds and the location of the box. In our experience, birds avoid these boxes and choose wooden ones when presented. However, other bird landlords have reported great success with plastic nest boxes.
If you’re debating about which to buy, and you’re on a tight budget, we recommend a wooden nest box as a good start.
Down the road, if you have a little more budget to experiment with, you can try out a recycled plastic nest box and give your old wooden one to an aspiring birder if the plastic one worked out for you.
The best recycled plastic bluebird nest box is the Birds Choice Ultimate Bluebird House. It’s spacious, comes with an extra guard around the hole, ladder for fledglings, drainage, two side openings for viewing and cleaning, light color and great ventilation.
Birds Choice specs
- Entry hole: 1.5 inches
- Material: recycled poly-lumber
- Access: Two side openings, one for cleaning and one for monitoring
- Venting: Side vent holes and drainage area near opening.
- Floor dimensions: ~ 4-⅜ x4-⅜
- Kerf: May no longer be present in new design
You can find this bluebird nest box on Amazon*.
Gilbertson Bluebird Boxes
Many bluebird trail monitors love the Gilbertson nest box model. This style of nest box is made from PVC drain pipe that is about 4-5 inches in diameter, and is topped with a wooden roof.
The roof portion is attached to the pole mount, usually conduit, while the PVC portion that holds the nest is easily removed for a top-down observation.
You may have read that the Gilbertson nest box style prevents house sparrows. However, no bluebird nest box is completely house sparrow-proof. The Gilbertson’s shallow depth design discourages house sparrows, but will not guarantee protection against attack.
Advantages of the Gilbertson nest box include the ease of monitoring, good photography, easy transport and easy cleaning.
There are some disadvantages of this nest box, however. Disadvantages include difficulty monitoring blowfly infestations, small size, and very thin walls that prevent good insulation from heat or cold.
You can find a DutchCrafters Gilbertson Nest Box on Amazon*
DutchCrafters Gilbertson nest box specs
- Entry hole: 1.5 inches and 1-⅛ inch available for chickadees
- Material: PVC with wooden bottom and poly-lumber roof
- Access: Top detachment from pvc box
- Venting: Unknown
- Kerf: Grooves are present for fledglings.
Peterson Bluebird Boxes
For many experienced trail monitors, a Peterson style box is a favorite.
The Peterson style bluebird nest box has a very slanted, wedge shaped design with benefits such as rain and sun protection as well as some predator protection.
With the slant shape that causes the box to slope downward when mounted correctly, rain doesn’t enter the nest box as easily, keeping nests dryer during heavy storms.
Furthermore, the slant shape makes it more difficult for racoons, cats and possums from getting into the nest box. However, we must warn that while the nest box creates more obstacles for mammalian predators, it does not guarantee protection. Always properly mount your nest boxes and use a baffle.
Another feature of the Peterson box, according to Steve Gilbertson (a notable nest box designer), is that the smaller interior only provides about 14 square inches of nesting space, which is too small for a Starling’s preference.
Starlings are invasive birds in North America and compete viciously for nest cavities. However, Dick Peterson and Steve Gilbertson both observed Starlings almost never attempting to enter a Peterson box due to its dimension.
In terms of bird preference, wooden Peterson boxes tend to be well accepted by bluebirds and tree swallows.
But if you’re just starting out as a bird landlord, and you’re trying to figure out which is the best box, we do not recommend starting with a Peterson box.
The design can create some potential hazards for an inexperienced monitor. For instance, the slope shape means there is risk of nestlings falling out when the box is opened.
Other disadvantages to consider when deciding on a nest box is the smaller interior space. The wedge shape means that the nesting area isn’t very wide. For broods of six surviving nestlings, things can get pretty cramped inside.
While the nest box design does help reduce sun exposure, which therefore minimizes heat, nest boxes with a smaller interior mean things can still heat up. And the more bodies inside a nest box, means more heat on a hot day.
There are Peterson boxes available on Amazon* but we really encourage you to read the reviews and look closely at the specs. In our review, we did not find any that meet our expectations.
The Coveside brand box on Amazon has poor reviews. The DutchCrafters box on Amazon currently has no reviews. However, it is made of poly lumber and is ventilated. You can also find nest box plans here.
Gilwood
The Gilwood box was designed by Steve Gilbertson. His goal, when designing the box, was to come up with a design that catered more to a bluebird’s natural preferences.
Design features of the Gilwood box include a 2.25 inch wide horizontal oval for entry, a larger entry hole for better ventilation and smaller interior dimensions, almost 15 square inches.
Like the Peterson box, the smaller dimensions are meant to deter other competing birds like European starlings. The horizontal entry oval is also believed to minimize predation.
Another advantage of a Gilwood box is the concept of ambient light. When observing bluebirds investigating a nest box, you’ll see them poke their heads in first a few times to see inside. However, when they do this, due to a round 1.5 inch hole, the light ends up being blocked.
What Gilbertson found is that the enlarged entry hole with the horizontal design still allowed light to get into the box, which allowed birds to better see inside and investigate. This might also lend to their preference for this box.
We could not find a commercially available Gilwood box on Amazon. However, you can find plans for a Gilwood box here.
Slot Box
The slot box bluebird house design uses a horizontal slot as an entry point rather than a round hole. This is another bluebird nest box style designed by Steve Gilbertson.
There is a lot of debate about its effectiveness. One of the big selling points is the claim that it deters house sparrows. However, a lot of people with experience with this box have found this just isn’t true.
One advantage this nest box style has when it comes to house sparrow attacks is the potential ease for escape. Because the horizontal slot spans the entire front of the box, it becomes harder for a sparrow to trap a bird inside.
Nest Watch covered a study testing how well bluebird nestlings thrive with this nest box compared to the classical round-hole entry design. Researchers of this study discovered fewer eggs are laid in these style boxes and boxes with the traditionally round whole had more fledges (Bailey, N.D.).
Another area for debate is potential exposure to predators. However, if you have a good baffle system and are regularly monitoring your nest box, this may not be an issue.
If you are interested in a slot box, Amazon* does have a Coveside brand box with decent reviews. In terms of quality, reviews favor this, but mention it is not sparrow resistant – as expected.
Birds Choice specs
- Entry hole: Slot
- Material: Wood
- Access: Front, opens from the bottom
- Venting: Side vent holes
2-Hole Nest Boxes (2-Hole Mansions)
The floor dimensions are 5-½ inches by 5-¾ inches, which is about 31.625 square inches. The extra room is beneficial, especially for larger clutches. Once nestlings get close to fledging, it gets very cramped in the nest box.
Another benefit to that larger interior is that if a bluebird or any other bird is being attached either by a predator or a house sparrow or starling, there is more room to move around and hopefully get free.
That second hole allows another escape. Imagine if a racoon slipped his paw into one hole trying to grasp the brooding mother, she could fly out of the second hole rather than be trapped inside.
More space and an extra entry hole can contribute to better air circulation, which is crucial during very hot days.
At extremely high temperatures, eggs can cook and nestlings could die. The airflow becomes very important.
How can you use a Van Ert Trap in a 2-Hole Mansion?
With two holes, the question then becomes, how do you trap a house sparrow if one is coming to the nest box.
We recommend installing the trap at one of the holes and using something to stuff close the second hole.
Usually, when trapping house sparrows or European starlings with a Van Ert Trap, you only want to use it if you know one is actively entering the nest.
The “two-hole mansion” bluebird nest boxes are larger nest boxes with two holes instead of one. The advantage is that it provides an escape route for adult birds under attack. The large, deep interior gives nestlings more room and protects them against predation.
Typically, when starting out with bluebird landlording, you’re not going to begin with this typeof nest box. Part of the reason for that is that they’re harder to find commercially.
Instead, you’ve got to build these yourself or know a bluebird who builds them.
Thankfully, Nest Builder’s website has plans you can print off if you want to build one yourself.
What makes the two-hole mansions different from regular nest boxes is that they are much larger. Rather than a 6 inch drop from the entry hole to the floor, it’s about an 8 inch drop.
The extra depth provides nestlings with better protection from reaching predators.
You can use a Blink Camera* from Amazon to monitor the nest box and see what’s coming in and out, and then set the trap if one has been visiting.
The other option is to make a decoy box using cardboard and set it fairly close to the 2-Hole Mansion. Again, you only want to do this if you know a house sparrow is actively in the area, and you have visual on the box.
We have a video about how to make a cardboard decoy box and install a Van Ert Trap inside.
Dangers of decorative birdhouses
There are some incredibly beautiful decorative birdhouses. If you truly love and care about birds, you should avoid using them unless you’re certain they allow proper protection, maintenance and monitoring.
Often, these decorative houses are bought at craft fairs and are made of interesting repurposed materials, like boots or old mailboxes or license plates. Or they’re bought for Mother’s day or birthdays or Christmas.
Unknowingly, people put them up and think they will be helping birds.
The reason decorative birdhouses are a bad idea for birds are:
- They tend to invite more predators, and the death of an adult reproductive native bird harms conservation efforts.
- They aren’t the proper thickness or material to ensure good insulation.
- They do not have access points for good cleaning and monitoring.
- They do not shield from rain. And a wet nest is a dangerous nest.
- They are more likely to be used by invasive birds like house sparrows (since they’ll nest in anything).
You can still put up a decorative bird house, but plug it up. If you landlord birds, it is important you use birdhouses that meet the specifications of that species.
Amazon and other bird stores will advertise window mounted bird houses so you can watch nesting birds from your window.
If you love and care for birds, do not, we repeat DO NOT buy one of these.
These types of nest boxes present too many risks:
- Overheating.
- Easy predation.
- Too many disturbances.
- Mother bird might fight her reflection and get injured.
- Suction cups will eventually stop working, and the whole thing falls.
- Poor insulation.
- Some options do not prevent moisture, and a wet nest is a dangerous nest.
- Often not large enough or made of quality wood.
We still encourage nest box monitoring, but in a safe way. We have a detailed article about safely monitoring nest boxes.
One of the best ways to monitor nest boxes and really capture the memories of it all is to buy a Blink Camera from Amazon*. These little motion-activated video cameras are wireless, waterproof and weatherproof. They also fit easily inside a nest box. We even have an installation video:
Landlording Other Native Birds
Bluebirds are not the only cavity nesting birds. Chickadees, tree swallows, and house wrens are a few other examples of the many native cavity nesting species in North America.
If you’re interested in landlording these birds, it’s important to research the specifications and order appropriate nest boxes.
On the bright side, the smaller cavity birds like chickadees are perfectly fine nesting in Bluebird nest boxes. For a chickadee, it offers them plenty of room. And letting them nest in a bluebird box, should they begin one, is absolutely encouraged. Chickadees only have one brood per year and need our protection as well.
We have a great guide on how to protect them if a nest begins in your nest box. One of the quickest, easiest solutions is by adding a 1-⅛ inch hole reducer so other birds cannot evict them.
If there are house wrens in the area, you can put up a second box further away, and add a wren guard to the chickadee box.
*Some links in this article contain affiliate links. If you choose to order something after clicking one of these links, the store provides us a very very small commission. You are charged nothing extra for this, and the small amount helps continue to support Nest Hollow. We thank you so much for your support.
