Have you ever looked at your own house, car, RV, office, or even a building that means something to you and thought:

“I wish I could turn that into a building block set.”

That is exactly where a custom MOC can begin.

MOC stands for My Own Creation, a term commonly used in the building-block community for independently designed models rather than standard retail sets.

A custom MOC can start from something as simple as a few photographs, or from a completely finished digital design with a parts list already prepared.

Here is how the process works.

1. Start With an Idea or Reference

The first step is deciding what you actually want to build.

Your starting material might be:

• Photos of a house or building
• A car, truck, RV, yacht, or other vehicle
• Architectural drawings or floor plans
• A company building or product
• A sketch or concept image
• A digital 3D model
• An existing MOC design
• A CSV or XML parts list

For real-world subjects, having photos from several angles is especially useful.

A single front view may show the general appearance, but side and rear photos can help a designer understand the proportions and details much more accurately.

2. Decide How Large and Detailed It Should Be

Before creating a custom LEGO-style build, one of the biggest decisions is scale.

A smaller model can be easier to display and usually requires fewer pieces, but some details will need to be simplified.

A larger model gives the designer more room for features such as windows, interiors, landscaping, mechanical functions, or detailed exterior shaping.

Think about a few things before starting:

Where will the finished model be displayed?

A desk model, an employee gift, and a large showroom centerpiece all require very different scales.

Which details matter most?

For a personal RV, recognizable exterior details may be the priority. For an office building, the entrance, company signage, or surrounding landscape may be more important.

Do you want an interior?

Interior rooms can significantly increase both the size and complexity of a project.

There is no ideal piece count. The right scale depends on the subject, display space, desired detail, and budget.

3. Choose Your Starting Point

There are generally two ways to begin a custom MOC order.

Option 1: You Already Have a MOC Design

Some builders already have:

• A completed digital model
• Building instructions
• A parts list
• CSV or XML files

In this situation, you may not need design work at all.

You can send the available CSV, XML, or other compatible parts list to LesDiy. We can review the required pieces and prepare a quotation for the parts needed to complete the model.

This is especially useful for larger MOCs where sourcing hundreds or thousands of individual elements yourself can become time-consuming.

Option 2: You Have an Idea but No Design

You do not need to know how to use brick-design software to create a custom model.

You might simply have:

“This is my RV. I want a brick-built version of it.”

or:

“We want to turn our company building into a Christmas gift for employees.”

In this case, photos, dimensions, drawings, and other reference material can be used as the starting point for a custom MOC design.

The concept is then developed into a buildable model before moving into parts production.

4. Turn the Idea Into a Digital MOC

For a project starting from scratch, a MOC designer first translates the references into a digital brick model.

This involves much more than making the finished model look similar to the original subject.

The designer also needs to consider:

• Structural stability
• Available brick shapes
• Available colors
• Building angles
• Connection strength
• Finished dimensions
• Practical assembly order

A shape that looks easy in a photograph can become surprisingly complicated when recreated with rigid building elements.

Curved vehicle bodywork, unusual roofs, angled architecture, and organic shapes often require experimentation with several building techniques.

A good custom MOC therefore needs to be both recognizable and buildable.

5. Test and Refine the Design

Digital design is only part of the process.

With more complex models, sections may also need to be revised to improve strength, appearance, or ease of assembly.

Large structures have to support their own weight. Long sections may require reinforcement. Decorative details that work digitally may need adjustment once real parts and gravity are involved.

This testing and refinement stage helps turn a visual concept into a practical building project.

6. Create the Instructions and Parts List

Once the design is finalized, it can be prepared for building.

Two important elements are normally involved.

Building Instructions

Digital instructions break the model into individual building steps so another person can reproduce the design.

Parts List

The parts list records the pieces, colors, and quantities required for the finished model.

Files such as CSV and XML can then be used when preparing a parts quotation.

If you already have these files, you can usually skip directly to the quotation stage.

Real Custom MOC Projects: What Do People Actually Build?

Custom MOCs are not limited to fantasy models or famous landmarks.

Some of the most interesting projects come from objects and places that have personal meaning.

We have received requests for projects such as these:

A Customer’s Own RV

One customer wanted to turn their personal RV into a building block model.

Instead of building a generic camper, the goal was to recreate the vehicle they actually owned and traveled in.

That makes the finished model much more personal than an ordinary display set.

A Shopping Mall Before Renovation

Another customer wanted to recreate a shopping mall they had previously operated.

The property was going to be renovated, meaning its original appearance would soon change.

Creating a brick-built version offered a way to preserve the appearance of the building as it had existed before the renovation.

A Company Building as a Christmas Gift

Custom MOCs can also be used for corporate projects.

One company approached us about turning their company building into a building block set that could be given to employees as a Christmas gift.

Instead of a conventional corporate gift, employees receive something directly connected to the place where they work.

These projects show that a custom building set can be more than a model.

It can become a keepsake, employee gift, display piece, or physical memory of a real place or object.

How Does a LesDiy Custom Order Work?

The exact process depends on whether you already have a completed design.

If You Already Have a Parts List

1. Send Your Files

Send the available CSV, XML, or compatible parts list.

2. Parts Review

We review the required parts, colors, and quantities.

3. Receive a Quote

A quotation is prepared based on the required parts.

4. Confirm the Order

Once the quotation is confirmed, the order moves into preparation and production.

5. Quality Check & Shipping

The parts are prepared, checked, packed, and shipped.

If You Need a Custom Design

1. Send Your Idea

Provide photos, drawings, dimensions, or other references.

2. Confirm the Direction

Important details such as approximate size, level of detail, and intended use are discussed.

3. Create the MOC Design

An independent MOC designer develops the model based on the provided references.

4. Review the Design

The model can be reviewed and refined before production.

5. Prepare the Parts Quote

Once the design is finalized, the required parts can be calculated.

6. Production & Delivery

The parts are prepared and the completed custom project moves toward delivery.

What Can Be Turned Into a Custom MOC?

Almost any subject with a recognizable shape can potentially become a custom building model.

Popular ideas include:

• Houses
• Office buildings
• Stores and shopping malls
• Factories
• Cars
• RVs and campers
• Trucks
• Boats and yachts
• Aircraft
• Company products
• Machinery
• Corporate gifts
• Original architecture
• Fantasy creations
• Science-fiction vehicles

The important thing is not whether the subject already exists as a retail building set.

That is the point of a custom MOC.

The subject can come from you.

Frequently Asked Questions

Can I make my own LEGO set?

You can create your own independent brick-built model, commonly known as a MOC or My Own Creation. It can be designed yourself or developed with the help of an independent MOC designer.

Can you make a custom building set from photos?

Photos can be used as reference material for a custom design. Providing several angles, dimensions, drawings, or other details can help the designer better understand the subject.

I already have MOC instructions. Can I just order the parts?

Yes. If you already have the design and a compatible parts list, such as a CSV or XML file, you can submit the file for a parts quotation.

Do I need a CSV or XML file to start a custom project?

No. Those files are mainly useful when the MOC has already been designed.

If you are starting from an idea, you can instead provide photos, drawings, dimensions, and other reference material.

Can custom MOCs be used as corporate gifts?

Yes. Company buildings, products, machinery, landmarks, and other subjects can be turned into custom building models for employee gifts, client gifts, events, or display purposes.

How many pieces does a custom MOC need?

There is no fixed piece count. The final number depends on the model's scale, shape, level of detail, and features.

Turn Your Idea Into Something You Can Build

A custom MOC does not have to begin with professional design software.

It can begin with a photograph.

A vehicle you own.

A building you remember.

A company you want to represent.

Or simply an idea that does not exist as a building set yet.

From there, the project can move through design, refinement, instructions, parts preparation, and finally into a physical model you can build yourself.

Already have a MOC design? Send us your CSV or XML parts list for a quotation.

Starting from an idea? Send us your photos, references, and project requirements and tell us what you would like to turn into a building model.

[START YOUR CUSTOM MOC PROJECT →]

LEGO® is a trademark of the LEGO Group. The LEGO Group does not sponsor, authorize, or endorse LesDiy or the independent custom MOCs discussed in this article.