How to build the ultimate cardboard fort

Here at Space Station, we understand that school holidays can be an expensive time. With parents spending an average of £300* per school holiday on taking their children out for activities such as the cinema, bowling or play centres, the costs can really add up.

So, to make it a little easier on the purse strings for parents this summer, we have created a guide on how to build the ULTIMATE cardboard fort! Not only is it a low-cost activity, but it also helps you bond further with your children, as well as develop their team-building skills and imagination.

All you will need to create your ultimate cardboard castle is a few household supplies, and lots of creativity!

To watch us create our cardboard fort, please view the video below:

Download a printable version of our instructions:

How to build the Ultimate Cardboard Fort pdf (1553 KB)


What you’ll need:

  • 12x cardboard boxes (or more/less depending on the desired size of your fort! These can be picked up cheaply, or ask your local homeware shop who
    may hold on to bigger boxes from stock)
  • Safety knife/scissors (adult supervision required)
  • Marker pen or pencil
  • Strong tape
  • Accessories to decorate your fort, such as flags or your favourite stuffed animals to warn off any intruders
  • Your imagination!


1. Firstly, collect all of your cardboard boxes. The quantity of boxes, and the size of the boxes, will depend on how big or small you want your desired
fort to be. We recommend around 12 boxes (8x medium boxes and 4x large boxes)

2. To create the turrets, you’ll need two medium boxes per turret. Firstly, open out all of the flaps of one box and then tape the flaps together so
the box stands upright and is secure. Make sure to tape the top and bottom flaps.

3. Repeat for the second medium sized cardboard box.

4. Stack the two taped boxes on top of each other and secure them together with more tape.

5. Using a marker pen or pencil, mark out the tops of the turrets.

6. Using scissors or a safety knife (adult supervision required), cut out the tops of the turrets using the guidelines you created.

7. Make three more turrets by repeating steps 2-6.

8. Using one of the large boxes, flatten it out and use it to connect two of your towers together with strong tape.

9. Repeat step 8, until all of your four towers are connected.

10. Mark out any doorways and windows you want your fort to have and cut these out.

11. Optional: Decorate your fort with any flags, poster paint or other decorations you may have.

12. Battle off your enemies in the safety of your new cardboard castle!