How to build an amazing castle for your princess party!

Princess Party: DIY Backyard Castle Tutorial.  What’s a princess party without a castle?  This castle tutorial will make your little princess smile and really make your party a royal affair!  Easy DIY instructions for an extra special party prop!

Looking for more princess party ideas?  Check out this princess party, this Disney inspired princess party, these princess party games, this Frozen princess party, these princess dress ideas and this princess crown tutorial!

castle tutorial photo

When we set out to plan my daughter’s Princess Party, I KNEW I wanted a giant castle.  Originally, I had planned to make one out of cardboard boxes.  


☑️ This Disney Princess Party Kit is the perfect set to get your party planning headed in the right direction! 

I found this adorable Castle on Pinterest.  I gave the pictures to my husband and said “can you make me this?”  A few days later, he blew me away when he presented me with plans for a large foam castle with realistic looking bricks.

 Rocked my socks.

Today, I’m sharing the tutorial, so you too can have an amazing play castle…

How to build a Princess Castle for your party


  • 8×4 sheets of insulation foam (1”-1.5” thick) size of castle will determine # of sheets needed
  • Paint stripping heat gun (we used this one: Kawasaki 840015 Black 10-Piece Heat Gun Kit )
  • 2” & 4” paint brushes
  • 4” paint roller
  • Paint trays
  • Black spray paint (flat)
  • 2 shades of grey paint
  • Duct tape
  • Foam saw or fine toothed hacksaw (without  the bar over the blade)
  • 2 cans of spray adhesive
  • Yardstick
  • Drop cloth


  • Measure 3 sheets into 2’x8’ strips
  • Using the saw, cut 3 sheets into 2’ x 8’ strips (6 strips). These will be used to make the two towers


  • Cut crenellations (the cutouts on the top of the wall that make it look “castle-y”) into one end of each strip.  Crenellations should be measured 6”x6” on the outer edges with the crenel (low part) being centered and measuring 12” long.

  • Using another sheet of foam, cut 4 rectangles measuring  6”x12”. These will be used to make the crenellations on the castle wallTurn a full sheet of foam on its side so it stands 4’ tall and attach the crenellations 1’ apart. 

  • Use the spray adhesive and then duct tape the back side



  • Draw and cut out doors, windows, arrow slits, etc. as desired.  Push the saw slowly into the foam and begin cutting at your desired location


  • Once all of the crenellations have been cut/attached lay all of the pieces of foam on the ground to carve the bricks.  Make sure the drop cloth is underneath the foam. (Heat gun will stain/burn brick and other exposed surfaces.)

  • Using a sharpie or other marker, draw out 6”x12” bricks onto the foam sheets.  These should be staggered to look like a brick wall

  • Once the bricks have been drawn, use the heat gun to melt grooves into the foam sheets.  The gun works very quick and will melt all the way through

    • Tip: Be sure to practice on scrap foam before you start melting your walls.  Deep pits can add character to your castle and mistakes can be covered up during the painting as long as they don’t melt all the way through


  • After the “mortar” lines have been melted, you can use the heat gun to add texture to the brick surfaces.  Move the heat gun quickly in a back and forth motion to prevent too much melting
  • After all of the bricks have been cut out, use the black spray paint to paint all of the “mortar” lines.  Spray paint will also melt the foam some

  • When the spray paint dries, use the four inch roller to paint on the darker of the two grey paints.  This paint should only be applied to the “brick” surfaces, not the “mortar” surfaces.  

  • The 2” brush can be used to thin the mortar lines and to get into any of the “brick” texturing that was left unpainted by the rollerIMG_9436

  • Once the darker grey has dried, use a dry brush technique to apply the light grey pain.  Use a 4” brush.  Get most of the paint off of the brush before you begin painting.

  • You only want to highlight the raised surfaces/texture of the bricks with the light grey, leaving the lower spots the darker grey.

  • Use the spray adhesive to attach all of the sheets together.  Spray each surface that will be attached and let the adhesive become tacky before pressing the pieces together.

  • As the spray begins to dry, use duct tape to secure the joints.  Tape along the inside of each jointIMG_9383

  • Secure the castle by taping it to existing posts or to the ground with rope & stakes.

Because the castle is made of foam, it is very light weight, so you will want to secure it in place. We also got the kiddos involved in the painting…they had a blast!!IMG_9692

IMG_9678Let me know if you have any questions about this castle tutorial.  Happy Castle Building!!!IMG_9023

Here are some helpful links for throwing a Princess Party:


If you love this tutorial, please pin this image to your Birthday Pinterest Board:


THANK YOU FOR READING OUR instructions for making a castle from foam!