Portable Shelter Construction Modules

Imagine this: it’s a summer picnic with your friends—and your dogs. You arrive at the park, and the first thing you need to do is to keep the car from overheating in the sun. So you grab a windshield sunshade.

Next, you look for a picnic table under tall, shady trees. Uh-oh—you're too late. All the good spots are taken! You didn't have the space to pack a big, clunky tent, either.

Finally, your curious dogs are sniffing everything and wandering off. At least one of you has to keep an eye on them the whole time to make sure they don't steal someone else's food. Wouldn’t it be nice if you had a portable dog fence?

We aimed to solve all of these problems in one project. Our goal was to create a system of modular pieces that could be assembled into a variety of different structures while also being portable, which would offer flexibility as well as ease of use.

We came up with these parallelogram-shaped folding units that can be assembled into various 2D or 3D shapes.

With 4 to 8 units, you can quickly build a windshield sunshade. Want to cover the side or back windows too? Just add more units.

With 16 units, you can create a temporary dog fence on any flat surface, giving them space to roam while you relax with friends. It may not be able to hold back a husky, but it's perfect for small dogs.

The same units can be assembled into storage containers to hold and organize your picnic gear, or even into a shelter to give you some much-appreciated shade on a hot summer day.

And the best part? These units are made from recycled, reusable materials, designed for sustainability AND convenience

Materials:

1. Cardboard-We used food delivery corrugated cardboard boxes.
2. (Optional) Silver plastic sheets for sun protection - we reused this silver food delivery bubble wrap
3. Packaging tape

Tools:

1. Scissors/cardboard cutters
2. Stapler

Our modular unit is inspired by the multicolored origami cube design (https://www.wikihow.com/Fold-an-Origami-Cube) and built to be both functional and adaptable.

Design Specifications:

Each unit is constructed from a shape composed of two isosceles right triangles (flaps) and one square (the body), forming a parallelogram with a base length of 24" and a height of 12". The acute angles measure 45°. The unit folds along the line where each flap borders the body.

We first built out our design with paper and tried creating a fence, then moved on to cardboard.

Front Face:

Cut a silver plastic sheet into a 12" x 12" square.

Tape this sheet securely to the front-facing square to provide sun reflection and basic weather protection.

Back Face (Pocket to Insert Flaps):

Cut two cardboard strips, each 6" wide.

Attach these strips to the side triangles using staples to form a pocket for connection to other units.

Trim any excess cardboard for a clean finish.

Note

Although most units have two flaps (U2), we will need some special units.

[1] Ending Unit with one flap (U1):

Ending units are placed at the edges of a structure and do not connect to additional units on both sides. These pieces include only one triangular flap. This reduces material, simplifying construction when no further extension is needed, and makes the shelter look better by ensuring there is no random hanging flap. If you do not want to calculate how many U1 units you need, you can always cut off one side triangle during assembly.

[2] Ending Unit with no flag (U0):

This is rarely used unless you only want to make a row. Essentially this becomes a square "pocket".

Build as many as you need, or in our case, till supply runs out.

Corners:

Assemble corner units following the illustrated configuration. Proper alignment at the corners ensures structural stability and a clean finish.

There is a wrong way to do this - If you do it correctly, you shouldn't need to stuff any flap into any pocket and it should all move very smoothly. See the diagram above.

Surfaces:

When designing larger surfaces or shapes, pay attention to the number of units used along each side.

Tip: Sides with an even number of units are generally easier to assemble. They simplify edge alignment and reduce the complexity of matching pieces at the boundaries.

To build an open box structure measuring 5x3x6 (open at the front and bottom), we calculated the required number of units as follows:

Sides: 3×6×2 = 36 units

Back: 5×6 = 30 units

Top: 3×5 = 15 units

Total: 81 units

We broke the build into two major components:

Main Body:

We created 5-unit vertical strips. and assembled them into one continuous piece of 11×6 units to form the left side, back, and right side. (Note that these strips wrap horizontally around the shelter, so their width is 3+5+3 = 11).

Top Panel:

We constructed a 3×5 panel with an additional 1-unit folding edge for attachment.

After assembling both components, we joined them to form the open box.

Revision & Redesign:

We found the base lacked stability. To improve it, we redesigned the structure with dimensions 3x4x6, this time intentionally allowing the bottom layer to "collapse outwards" (please refer to "base" design in proof of concept) for added support. We also added a bottom panel.

This new version required more units:

Sides: 3×6×2 = 36 units

Back: 4×6 = 24 units

Top and Bottom: 3×4×2 = 24 units

Total: 84 units

In this case, we gave the structure a base to provide more stability. Note that making a base requires more units. In the end, unfortunately, we ran out of cardboard near the end and had to stop slightly short

While the final structure wasn’t as sturdy as we hoped, the process was fun and full of valuable learning experiences.

[1] Weight of the Structure

We found that hollow cardboard structures are often not strong enough to hold its own weight, especially as the structure gets taller. To address this, we experimented with corrugated plastic board, which is lighter. However, it comes with its own trade-offs: it’s more expensive and requires different tools and techniques for binding, with hole punching and zip ties replacing staplers. The cost goes up and the environmental benefits from reusing cardboard are reduced

[2] Binding Methods

We tested both tape and staples for binding the units. Staples performed better—they’re tighter and don’t easily stretch like tape does. That said, a more professional-grade heavy-duty stapler would likely improve strength and ease of assembly further. Staples can easily scratch you while you're assembling the structure

[3] Waterproofing

To function effectively as an outdoor structure, waterproofing is essential. We tried using silver delivery bubble wrap bags to provide some protection from the sun, but they are powerless against the rain.

[4] Build Time

Constructing a 4x4x6 structure took three people about one and half hours to build. A lot of this time was spent carefully handling staples to avoid injury. Even in an optimized setting, it can still take 30 minutes to build. One idea to speed up the process is to introduce pre-built units in larger sizes (e.g., 2-unit, 3-unit, or 5-unit segments). This would still offer flexibility and stability in structure design while reducing assembly time. Of course, it would also limit customization and slightly worsen portability, so there’s a trade-off to consider.

[5] Bending

While each modular unit holds fine, the joints can still bend either way, which might be confusing for people trying to assemble it. This can be avoid by making sure the joints can only be fold one way. It is a little bit hard to do with cardboard without introducing excessive weight or complexity in binding.

Final Thoughts

Realistically, the most effective solution might be an industry-manufactured modular system made from lightweight plastic—ideally with one side tinted to shield against sunlight. While this moves away from recycled materials, it would solve many of the issues with weight, durability, waterproofing, and ease of use.