> ## Documentation Index
> Fetch the complete documentation index at: https://help.parafin.ai/llms.txt
> Use this file to discover all available pages before exploring further.
# Constraints and sorting
> Apply design constraints and sort by financial metrics to find the best options for your site.
{/* Figma source: Design Constraints side sheet (Building On) https://www.figma.com/design/hevlKEYRL9U8bXkXiKqMky/Parafin?node-id=12383-81688 */}
Parafin generates thousands of candidate designs per site. The **Constraints** button in the project panel opens the **Design Constraints** side sheet where you narrow the set to designs that meet your requirements. The **Zoning** button next to it opens the [Zoning Panel](/tutorials/zoning-panel) for district details and zoning-only constraints like FAR.
## Design Constraints side sheet
Click the **Constraints** button to open the **Design Constraints** side sheet. Sections include:
* **Site Open Space**: minimum percentage of the site that must remain open
* **Building**: number of floors and maximum building height
* **Room Mix**: percentage ranges for Single, Double, and Suite room types
* **Program Options**: building entry type, meeting rooms, pool
* **Budget**: development budget range
The **Building** section shows a **Floors** selector (pick 3, 4, 5, or 6) and a **Height** constraint with the zoning baseline and a histogram of how variants distribute across height values.
## How zoning and design constraints work together
Some constraints appear in both the **Zoning Panel** and the **Design Constraints** side sheet, specifically **maximum building height** and **minimum open space**. When zoning data is available, these constraints show the zoning baseline value (e.g., "Zoning: Max 80ft") and an **Edit Zoning** link.
You can make these constraints **more stringent** than the zoning baseline (e.g., set max height to 60 ft when zoning allows 80 ft), but you cannot make them **less stringent** than what the zoning code allows.
A checkmark next to the value shows whether your setting meets the zoning requirement:
* **At Zoning**: your value matches the zoning baseline exactly
* **Stricter Than Zoning**: your value is more restrictive than the zoning baseline
Other constraints, like **FAR** and **setbacks**, are managed exclusively in the [Zoning Panel](/tutorials/zoning-panel) and don't appear in the Design Constraints side sheet.
## Sorting variants
The variant list on the left side of the project panel ranks designs by financial metrics. Use the **Ranked by** control to sort by **Yield**, **Key Count**, **Equity Multiple**, or **Budget per Key**. The list reorders in real time.
## Starring variants
Click the star icon next to **Show Favorites** to pin preferred variants to the top of the list regardless of sort order.