Finch 101: Generating Unit Mix

In this tutorial, we’ll use Finch to generate a unit mix around a corridor.

1. Start with a Predefined Floor

Open the Finch Sample Project, variant 3 Custom Core.

Steps:

  • Confirm you’ve already generated a corridor using Finch or imported one from Revit/Rhino.

  • Open the Programs drawer to ensure the floor contains:

    • Residential

    • Circulation

2. Confirm Space Types

Finch needs to understand which areas are corridors to ensure proper unit access.

Steps:

  1. Double-click on the corridor space

  2. Click again to open the space type settings

  3. Ensure the space is marked as Corridor

mportant: Without the correct space type, Finch won’t recognize this area as a circulation path.

3. Set Up Symmetry (Optional)

If your building is symmetrical (e.g., U-shaped), you can use this trick to generate mirrored unit layouts.

Steps:

  • Use the Draw Walls tool

  • Snap to midpoints on both sides

  • Draw vertical lines to split the plan into symmetrical halves

Finch will recognize these mirrored spaces and apply symmetric logic during generation.

4. Select Areas for Unit Mix Generation

  • Select the two exterior spaces flanking the corridor (e.g., outer arms of the U shape)

  • Click "Generate Unit Mix Around Existing Corridor"

Finch will begin iterating, using your plan library to generate apartments adjacent to the corridor.

5. Customize Your Unit Mix

Use the left-hand panel to define your apartment strategy.

Unit Mix

  • Set the desired distribution. For example:

    • 50% → 95 m² (3-bed)

    • 50% → 75 m² (2-bed)

    • Remove smaller units if not needed

Finch will re-iterate each time you change these percentages.

6. Adjust Priorities with Sliders

Sliders help balance your design intent:

  • Unit Mix: Enforce target mix percentages

  • Size Metric: Prioritize apartment area accuracy

  • Grid Lines: Align units to structural or design grid

  • Daylight Access: Maximize façade exposure

  • Squareness and Adjacencies: Improve interior logic and flow

Use the info icons for on-the-fly tooltips.

7. Refine Constraints and Settings

Key Constraints

  • Minimum Unit Width (e.g., 5 meters): Avoid long, narrow units in deep buildings

Core Alignment

  • Align Walls with Core: Keep layout orthogonal

  • Turn off for more organic/perimeter-following layouts

Wall Settings

  • Party Wall Width: Adjust thickness (e.g., set to 300 mm)

8. Review Metrics

Below your plan view, Finch shows:

  • Match Score: How close the result is to your target mix

  • Fit: How well the floor area matches your mix (e.g., ±30 m²)

  • Unique Units: Identifies duplicate units for efficient smart-copying

9. Apply and Fine-Tune

Once you’re satisfied:

  • Click Apply Plan

You can now:

  • Manually edit wall alignment using the Align Tool

  • Clean up junctions or adjust geometry to match design preferences

10. Check Your Results

Go to the Programs drawer:

  • See the total number of units generated

  • View unit size breakdown and location

Example: “16 apartments total, with a 50/50 mix of 75 m² and 95 m² units.”

Summary

You’ve learned how to:

  • Validate circulation space types

  • Use symmetrical logic for consistent layout

  • Customize unit mix targets and dimensions

  • Balance grid alignment, daylight, and spatial constraints

  • Apply and refine your generated layout

➡️ In the next tutorial, we’ll cover how to adjust individual units and use smart copy-paste tools for faster plan development.

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