How To Build an Easy Geodesic Dome

Last term we held an architecture class with the grades 1-3 age at our co-op group. My friend April led it while I was her “assistant”, but I had the opportunity one of the days to lead a class on domes.

We usually try to do a few visuals, but mostly discussion and hands-on learning with this class – because who doesn’t love to build stuff?! Somehow I got it into my head to build a geodesic dome. A what? (More on geodesic domes here.)

Basically, because of it’s structure (an arch), it is one of the most reliable and sound shapes used in building. Made up of many triangles, when you apply pressure/weight to one side of the triangle, the weight is evenly distributed to the other 2 sides, which transfers pressure to the attached triangles. That’s amazing weight distribution!

Remember this scene from Frozen, where Elsa is building her ice palace? The roof is a geodesic dome!

We started off the class learning a bit about domes and looking at pictures of buildings from ancient history to current day in which domes are incorporated.

Of course, knowing just how strong domes are, we decided to test it out. Our experiment included egg shell halves and a stack of books. I’m sure you can see where this is going?

How many books can an empty egg shell hold up? We started off with guesses of 1, 2, maybe 3 books. Once we reached 2 heavy books the kids quickly changed their minds. Finally, at 6 books and a stuffed animal, the eggs cracked under the pressure.

The power of the dome!

With about 45 minutes left in our class, we divided the kids up into 3 groups of 4-5 kids – the goal was to work together to build a geodesic dome out of straws and tape. All but 1 group (oddly enough, the group with the most kids in it had the hardest time!) finished their domes in the time that was left! And they are SO COOL!

How to Build an Easy Geodesic Dome

Step 1:

Cut 35 blue straws 12 cm long. Cut 30 red straws 11 cm long. Tape 10 blue straws together end-to-end to from a ring. This is the base of the dome.Step 2:

Tape one end of a blue straw to each end of one of the straws in the base ring. Bring the other ends of these straws together above the base straw. Tape these ends together to form a triangle.

Step 3:

Tape one end of a red straw to each end of the next straw in the base ring. Tape the ends of these straws together to make another triangle. Use blue straws to make a triangle over the next base straw. Alternate red- and blue-straw triangles all the way around the ring. This will form ten triangles.

Step 4:

Tape 10 red straws together end to end to form another ring of straws. Attach to the top of the triangles. (This will bring the triangles toward the center of the dome and begin to form the dome shape.)

Step 5:

Tape the ends of two blue straws to the right end of a red straw in the top ring. Tape the end of a red straw to the left end of the same red straw in the ring. Move around the ring alternately taping on two blue straws or one red straw at each junction of the ring. You will have five red straws and ten blue straws pointing into the center of the ring. The blue straws will be in pairs.

Step 6:

Grasp the loose end of one of the red straws you just added. Move along the ring to one of the two blue straws you just added. Tape together the loose ends of these straws. Go around the ring in the other direction and tape the loose end of one of the two blue straws to the ends of the two straws you just taped together. This will form a new triangle on each side of the red straw. Continue doing this around the ring forming ten new triangles.

Step 7:

Tape one end of five blue straws together to form a star shape. Tape a blue straw between the ends of each of the points of the star, making a pentagon with a star in the center. This is the top of the geodesic dome. Tape it on top of the dome, by attaching the corners to the junctions of the red and blue straws on the top row of triangles.