What is a scale model and a prototype?
A scale model is a smaller (or bigger) copy where all lengths are changed by the same ratio. The scale 1:100 means 1 unit on the model stands for 100 units in real life. Shapes stay the same; only the size changes.
A prototype is a test version. A study model is quick and rough, made in card or foam to try ideas. A presentation model is neat and shows the final design to clients. A working model tests how something works, such as a structure that carries a weight or a sun shading device.
Choosing and using the scale
Common scales: 1:500 and 1:200 for city and site models, 1:100 and 1:50 for buildings, 1:20 and 1:10 for details like a staircase or a joint.
Conversion: model length = real length ÷ scale number; real length = model length × scale number. Example: a 12 m wall at 1:50 is 12 ÷ 50 = 0.24 m = 24 cm. Pick a scale so that the model fits on a table but still shows the details you need. Areas change with the square of the scale; volumes with the cube.
Materials and building in layers
Materials: card and board (cheap and easy), foam board (light, clean edges), balsa wood and sticks (for frames), clay (for land shapes), acrylic sheet (for glass), wire (for railings), 3D-printed parts.
A common method is to build in layers: cut one slab for each floor or one contour for each level of the land, then stack and glue. Always draw and measure first; cut with a sharp knife on a cutting mat, away from your fingers.
Tools: manual, mechanical and digital
Manual: scale ruler, set square, craft knife, scissors, glue, pins. Mechanical: saws, drills, sanding tools, hot-wire foam cutter. Digital: laser cutter (cuts card from a CAD drawing), CNC router (carves wood or foam), 3D printer (builds layer by layer from plastic). Virtual models are 3D models on a computer that you can rotate and walk through.
Workshop practice: wear eye protection, keep the bench tidy, never rush a cut, and learn the safety rules of each machine.
Survey first: measure the real thing
To model an existing building, survey it: measure heights, widths and details with tape or laser, take photos and draw a plan and elevation (see the lesson Architectural survey). Then divide each measure by the scale to get model sizes. For land, use a site plan with contour lines and build the ground in layers.
Try it: make a 1:100 tower
Take 10 thin card pieces, each 3 cm × 3 cm. Stack them with glue: the tower is 10 floors. At 1:100, each floor is 3 cm, which is 3 m in real life. How tall is the tower in real life? Then change the slider in the 3D to 1:200 and guess the model height before reading it.
Key formulas and definitions
- Model length = real length ÷ scale number
- Real length = model length × scale number
- 1:100 → 1 cm = 1 m; 1:50 → 1 cm = 0.5 m; 1:200 → 1 cm = 2 m
- Area scale = (scale number)², volume scale = (scale number)³
Worked examples
1. A building is 30 m tall. How tall is its model at 1:100?
30 ÷ 100 = 0.3 m = 30 cm.
2. A model wall is 15 cm long at scale 1:50. What is the real length?
15 × 50 = 750 cm = 7.5 m.
3. A tower has 10 floors of 3 m each. At 1:100, how thick is one card slab layer?
3 m ÷ 100 = 3 cm per floor.
4. A garden is 20 m × 10 m. Will a 1:200 model fit on a 15 cm × 10 cm board?
Model = 20 ÷ 200 = 0.1 m = 10 cm by 10 ÷ 200 = 5 cm. Yes, it fits.
Common mistakes
- Multiplying instead of dividing when shrinking to a model.
- Mixing units: change all lengths to the same unit before dividing.
- Changing only the height and not the width. Every length must use the same scale.
- Cutting without a mat and ruler, or cutting toward your hand.