# Pick Your Model Path

Part of the Model Design and Building Merit Badge Digital Resource Guide: [Introduction & Overview](https://merit-badge.university/merit-badges/model-design-and-building/guide/index.md)

*4. Choose Your Build*

> **4.** Build Your Model. Do ONE of the following using physical and/or computer design methods. Before beginning any model, discuss your approach with your counselor, including the possible use of computer design software such as CAD or 3D modeling tools. Present your plans and completed model to your counselor.

You must choose exactly **one** option from this requirement. Each path teaches the same design habits — planning, scale, material choice, and revision — but each one emphasizes a different kind of thinking.

## Your Options

- **[Req 4a — House in Miniature](https://merit-badge.university/merit-badges/model-design-and-building/guide/req4a/)**: Design a scaled house model with floor plans, elevations, doors, windows, and exterior details. You will practice layout, proportion, and presentation.
- **[Req 4b — Showing How a Building Stands](https://merit-badge.university/merit-badges/model-design-and-building/guide/req4b/)**: Build a framing-corner model that highlights studs, joists, rafters, and other structural parts. You will learn how buildings carry weight and stay rigid.
- **[Req 4c — Mapping Water In and Waste Out](https://merit-badge.university/merit-badges/model-design-and-building/guide/req4c/)**: Model a house plumbing system with supply lines, drains, and venting. You will learn to think in systems and flow paths.
- **[Req 4d — Motion with Simple Machines](https://merit-badge.university/merit-badges/model-design-and-building/guide/req4d/)**: Build a working device that uses at least two simple machines. You will focus on force, motion, and function.
- **[Req 4e — Designing a Scaled Passenger Vehicle](https://merit-badge.university/merit-badges/model-design-and-building/guide/req4e/)**: Measure a real vehicle and turn those observations into a scaled model. You will practice proportion, exterior form, and multi-view drawing.

## How to Choose

**Choosing Your Option** — Compare the kind of work each project asks you to do

- [ ] **Time and detail**: The architectural and vehicle options often require lots of visible detail. The structural and mechanical options can be more focused if you want to show function clearly.
- [ ] **Best for hands-on building**: The structural and mechanical options are especially good if you want to cut, assemble, and test parts physically.
- [ ] **Best for systems thinking**: The plumbing process model is strong if you like understanding how hidden systems connect and flow.
- [ ] **Best for visual design**: The architectural and vehicle options are ideal if you enjoy shape, appearance, and presentation from multiple views.
- [ ] **What you will gain**: Architectural work builds design communication, structural work builds construction understanding, process work builds system mapping, mechanical work builds motion and problem solving, and vehicle work builds proportion and industrial-design thinking.

| Option | Main focus | Good choice if you enjoy... | Main challenge |
|---|---|---|---|
| 4a Architectural | Space, layout, appearance | Houses, room design, presentation models | Keeping scale and details consistent |
| 4b Structural | Framing and support | Construction, how things stand up | Making the skeleton clear and accurate |
| 4c Process | Systems and flow | Plumbing, diagrams, hidden systems | Keeping all lines readable |
| 4d Mechanical | Motion and force | Gadgets, moving parts, testing ideas | Getting the device to work smoothly |
| 4e Industrial | Form and proportion | Cars, vans, buses, exterior styling | Translating measurements into clean model views |

> **Tip**
>
> If you are undecided, choose the option that gives you the clearest access to real reference material. A project becomes much easier when you can look at the real thing, measure it, sketch it, and compare your model to it as you build.

> **Be Prepared! Before You Commit**
>
> Ask yourself:
>
> - Can I get or observe the reference information I need?
> - Do I have the tools to build this safely?
> - Can I complete this at the required scale without the project becoming too big?
> - Am I more excited about how it looks, how it works, or how it is organized?
>
> Your answers usually point to the right option.

Video: [New to Scale Modeling? Avoid These Five Beginner Mistakes! — SpruesNBrews Scale Modeling](https://www.youtube.com/watch?v=tn2SnnhHoLo)

The first option is the architectural model. Even if you end up choosing a different build path, reading through one option carefully can help you understand the level of planning your own project will need.

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- Previous: [Planning Your Original Project](https://merit-badge.university/merit-badges/model-design-and-building/guide/req3/index.md)
- Next: [House in Miniature](https://merit-badge.university/merit-badges/model-design-and-building/guide/req4a/index.md)