How to Make a Cat House: Easy Cardboard Designs for Every Cat

If you’re looking for a simple, low-cost way to upgrade your cat’s comfort, building a DIY cat house is the perfect project. Cardboard makes it easy to design a safe, stylish space without any woodworking skills. From creating doorways to adding extra rooms, you can customize it completely. This guide teaches you how to build a durable cardboard cat house from scratch.

Materials and Tools Needed (Beginner-Friendly)

You can build a functional and comfortable cat house with just a few basic supplies:

Basic Materials

This project is ideal for beginners, no advanced tools required, no complex measurements, and full creative freedom.

Choosing the Right Box Size and Layout

A well-sized box helps your cat feel safe and relaxed, offering the perfect balance between snugness and comfortable space.

Ideal Dimensions for Most Cats

For a single adult cat, a cardboard box around 2 ft × 3 ft works extremely well. This size gives enough space for standing, turning, stretching, napping, and even playing. However, cats come in different shapes and sizes, so consider the following adjustments:

If the box you have is smaller, don’t worry, you can easily combine two or more boxes to create a larger, multi-room design.

Why Sturdy Cardboard Matters

Not all cardboard is created equal. Thicker, corrugated cardboard provides:

•  Better structural support
•  Safer walls for scratching
• A stronger base for upper levels
•  More stability during jumping and landing

Weak or floppy cardboard bends easily and may collapse when tape, bedding, or toys add weight. Always test the box’s strength by gently pressing on the sides and top before building.

Indoor-Only Limitation

Cardboard is fantastic for indoor use, but it should never be used outdoors. Cardboard houses cannot withstand: 

• Moisture or humidity
• Rain or snow
• Damp ground conditions 
• Outdoor pests like termites

Exposure to moisture makes cardboard soft and unstable, increasing the risk of collapse. For outdoor use, materials like plastic bins, plywood, or insulated shelters are far safer choices.

Safety Guidelines Before You Begin

Safety is essential while building and while your cat uses the house.

1. Ventilation

Ensure enough airflow by adding:

• A main entry door
• Optional windows
• Side viewing slits
• Safe, Smooth Edges (Trim ragged cardboard edges to prevent scratches.)

2. Structural Stability

Tape corners well and reinforce weak spots. Wobbling or bending can frighten a cat and prevent them from using the house.

3. Keep Cardboard Dry

Moisture weakens cardboard quickly. Keep the house indoors and away from kitchens, bathrooms, or damp basements.

4. No Food or Water Inside

Placing food or water bowls inside leads to spills and collapse.

How to Build a Cardboard Cat House (DIY Step-by-Step Guide)

A simple cardboard cat house can give your cat a cozy hideaway, multiple rooms to explore, and a safe space to relax. Follow this complete DIY guide to build a sturdy, comfortable, and fun cardboard cat house using basic household materials.

Step 1: Find Several Sturdy Cardboard Boxes

The foundation of a durable cat house starts with choosing the right boxes.

How to Choose the Right Boxes

• Pick boxes with no chemical smells
• Avoid boxes with oil, water, or food stains
• Choose boxes that hold their shape without sagging
• For multi-room designs: gather two or three same-sized boxes

tep 2: Cut the Entry Doors and Windows

Creating openings improves airflow, visibility, and makes the house feel inviting.

Entry Door Height

Cut a main door around 6 inches tall, ideal for most adult cats.

Window Options

• Add small viewing holes
• Cut thin horizontal strips for airflow
• Make 1–2 windows per room for light and comfort

Add Fabric Flaps for Privacy

• Tape or glue light fabric around the openings
• Helps create a warm, den-like environment cats love

Safety Tip: Always cut away from your body and protect your surface with scrap cardboard or a cutting mat.

Step 3: Connect and Tape Additional Boxes

If you want multiple rooms or a second floor, this is where the house comes together.

Adding Extra Rooms

• Tape boxes together side-by-side
• Cut interior doorways to connect rooms
• Ensure openings align before taping permanently

Building a Second Level

• Cut a 6-inch ceiling opening in the bottom box
• Place a second box upside down on top
• Leave enough flooring for your cat to walk comfortably

Best Tape Choices

• Duct tape: strongest and long-lasting
• Packing tape: clean finish
• Avoid masking tape: too weak and peels off fast

Step 4: Make the Interior Cozy and Fun

This is the step where your cat feels the comfort and enrichment.

Add Soft Bedding

• A small blanket
• An old cotton sweater
• A lightweight cat bed

Add a Scratching Surface

• Tape a rough towel to the wall
• Or attach a small piece of sisal for vertical scratching

Add Toys

• Place interactive toys in lower rooms
• Hide small toys on top floors to encourage climbing

Step 5: Keep Food, Water, and Litter Outside

Moisture and cardboard never mix, keeping these items outside protects the structure.

• Place bowls just outside the entrance
• Keep the litter box nearby but separate
• Show your cat the new setup on the first day so they adjust quickly

Customization Ideas for Comfort and Style

Once the basic structure is complete, you can elevate the look and experience.

1. Add Extra Windows

Round or square windows make the house feel spacious.

2. Personalized Décor

Decorate with:

• Stickers
• Recycled wrapping paper
• Printed name tag

3. Removable Roof Option

A detachable roof makes cleaning easier and improves ventilation during warm weather.

Size and Comfort Tips for Different Cats

Reinforcement Tips for Durability

Cardboard houses naturally weaken over time. Strengthening early helps extend their lifespan.

1. Strengthen Corners

Use double tape layers inside and outside.

2. Add a Floor Panel

Place a second sheet of cardboard at the bottom for extra support.

3. Protect the Base

Put the cat house on a rug, foam mat, or thin plywood sheet.

4. When to Replace

Replace the house when:

• Cardboard is sagging
• There is visible moisture damage
• The house no longer stands firmly

This easy DIY project gives your cat a personalised indoor hideout made from everyday materials. As your cat enjoys their new space, you might eventually want something more stable especially if they explore outside. In that case, choosing a durable Outdoor Cat House provides the weather protection and long-term structure cardboard can’t offer.

FAQs

1. Why won’t my cat use the cardboard house I made?

Many cats need time to explore new spaces. Try placing the house in a quiet area your cat already likes, add a familiar blanket, sprinkle a little catnip, or leave one side open for better visibility until they feel secure.

2. Can I place a heated pad inside a cardboard house?

Only if it’s a low-heat, pet-safe pad and there’s enough ventilation. Never use electric blankets or high-heat devices; they can overheat cardboard. For long-term warmth, a heated insulated cat house is safer.

3. What if my cat keeps tipping the cardboard house over?

This happens when the house is too light or top-heavy. Add a second cardboard floor panel, place it against a wall or corner, or put a small weighted object (like a book) under the bottom layer to stabilize it.

4. What if the second level collapses when my cat climbs it?

You probably need stronger support. Add two cardboard beams under the upper floor, use double-layered cardboard for the ceiling, and reinforce all connection points with duct tape.