Dedicated to making the world a

better place one squirrel at a time

Building a Safe Squirrel House

Measure & Cut

Assemble & Fill


What do you call a squirrel house with a big entrance?  

A possum house!

We love possums

too, but if you want

squirrels in your

squirrel house,

the door needs to

fit the target species.

Flying squirrels 1.5-2, chipmunks 2” opening. Pine squirrels (Red and Douglas) 2.5”. The largest squirrels, Grays and Foxes 3”.  Even chubby possums can enter through a 3” hole so consider including a predator guard and/or inner ledge (below).

There are a lot of designs out on the Internet and most can be modified to incorporate features you want, while removing those you don't.  Below are basic instructions to how we build boxes for our squirrels and links to some other designs you might consider also.     

You will need a basic Jig saw and electric screwdriver to cut the boards and assemble the pieces. You can use nails; however, we found that the boxes didn’t hold up as well as when we secured the pieces with screws.



1 board   -  8’ x 6”-10”

Width based on avg. species size: 6” for chipmunk/flyer, 8” Douglas/Red, 10” Gray/Fox

Select a board made of non-aromatic wood. We use pine, seconds or rejects from the lumber  yard, or even old siding boards - whatever we can find as long as its not cracked, overly warped or toxic.  For large litters, you may consider a 12” width.  Keep in mind that squirrels like to snuggle in on cold nights so don’t go overboard on the size.  The larger the box, the heavier the box - a distinct disadvantage as you balance with a box full of squirrels on a ladder 30’ feet up.  Avoid particle board, it tends to disintegrate when wet.

2 boards -  12” x 12”  or more

One board each for roof and floor (or whatever size will provide a 4” or more overhang, ledge)

3 - 4 dozen screws

24 - 1.5” screws to assemble the box, 8-10 3/4” shorter screws may be required to attach the hardware to the box without penetrating into the interior, 8-10 2” or longer screws to affix the box to the tree.

Waterproof sealant or caulking

Fill in gaps, cracks or screw holes or ‘mistakes’ to ensure the interior remains dry during inclement weather.

Bedding material - enough to fill the box half full

Pillow fluff from an old pillow or stuffed animal or other material that is warm but dries out quickly if wet.  Another excellent choice is dried moss from a craft stoor.    

Mounting hardware

At a minimum, attach mountings at the top, sides, and bottom We use a single L strap installed at an angle to the top of the box with tie plates at sides and bottom.

Buying a Squirrel House
Building a Squirrel House

Planning is vital to giving ensuring each squirrel gets the best shot at survival.  Planning starts early in the rehabilitation process, from raising the squirrel in an appropriately sized release group, building a house, selecting a site, and taking into consideration factors and time of year.

Buying a squirrel house

Measure 18 inches on one side, 17 Inches on the other. Draw a line through the two lines and cut at an angle.

Tip: It’s important that the cut be straight to avoid gaps between the walls and the roof.

Cut the second side piece to be identical to the first.

Tip: Flip the cut piece over on top of the remaining board and align the angled edges flush. Mark the strait edge. The ensures that the two side pieces are identical.    

Cut the front board 17” long and the back board 18”.

Tip: if the side boards were not cut to exact measurements, cut the front board based on the length of the shorter side of the angled side pieces and the back board based on the longer side.

Cut the top and bottom pieces. The top needs to overhang the door and cover the leading edge of the backboard. The back of the house will lie flush against the tree.  Cut the opening on the longer edge of one of the side boards.

Screw the the four sides together. Match the long edge of the side pieces to the back board and the short edges of the side pieces to the front board. There should be no gaps in the seams. Gaps may be sealed with waterproof kitchen or bathroom sealant/caulking.

If you plan to insert an inner ledge, cut a piece of scrap wood and screw into place firmly.   

Tip. Position inner ledge with the solid ‘landing’ beneath

Door to shield interior from rain and  predators from reaching directly into the nesting area.

Tip: It’s important that the cut be straight to avoid gaps between the walls and the roof.

Flip the house over and screw on the bottom piece firmly.  Drill holes to ensure drainage if water gets onto the interior.  Flip the house the other way and fill with moss or fluff half way to the Top (Filling will compress significantly).

Screw the top on.  Fill  cracks, knotholes, and screw points with sealant to ensure water cannot leak into the interior.  Tip: To avoid cracking the wood, don’t drill too close to the edge.

Lastly, attach mounting hardware.

There’re many choices for hardware from attaching the box to a board and nailing the board to a tree.  Here we have used one L- strap and two Tie plates; however an inverted T-strap or retrofit plate can be used as well.

Tip: Take care screws are properly placed or shorter to ensure their sharp tips don’t intrude into the interior.

Releasing Squirrels
Building a Squirrel House

Information that will help you to increase the likelihood of survival post release.

Releasing Wildlife

This design can be modified for building indoor boxes appropriate for young and disabled squirrels by shortening the height and lowering the door.  Tip:  for easy access, add a hinge to the top at the back and a locking hook and eye set on the front.

How to build a squirrel house for.....

Gray Squirrel

Pine (Douglas) or Flyers

Squirrels  (Recycled Tire)