Load Criteria: Project-Level Loads
Define a project-wide set of loads that calculations can draw from as a single source of truth.
Load Criteria is the curated list of design loads (in psf) that belongs to a project. Instead of re-typing the same dead and live loads into every beam and post, you define them once here and pull them into individual calcs — keeping the whole project in sync with one source of truth.
What Load Criteria is#
Each project has a single Load Criteria set: a list of loads grouped by category — Dead, Live, Wind, and Snow. Every load carries:
| Field | Meaning |
|---|---|
category | One of dead, live, wind, snow |
name | Label for the load (e.g. "Roof assembly") |
applies | Where it applies (e.g. Roof, Floor, Wall) |
psf | Magnitude in pounds per square foot |
source | The citation shown in the app (e.g. "IBC 2021 Table 1607.1") |
kind | Optional: assembly, allow, or custom |
note | Optional free-text note |
id | Stable identifier used to link the load into a calc |
The id is what makes a load a reusable reference: when you pull a load into a calc, the calc remembers which criteria load it came from. See Link Loads into a Calc.
Wind and Snow are "linked" categories whose dedicated tools are coming soon. For now they appear as read-only placeholders, and new editable loads land in the Dead category.
Seeded on first access#
You don't start from a blank page. The first time you open a project's Load Criteria, ClearSpan lazily seeds it with a realistic starter set of Dead and Live loads — roof, floor, and wall assemblies, MEP and partition allowances, and common code live loads (residential, stairs, garage, office, roof live load). These are realistic placeholders under IBC 2021 / ASCE 7-22, not verified results — edit them to match your project.
Because the set is seeded only once and the ids are stable, reopening the page never duplicates loads.
Managing entries#
Open Load Criteria from the project, then work in the three-column editor:
- Pick a category in the left rail (Dead, Live, Wind, Snow).
- Click Add load (or Add … load for the active category) to create a new entry.
- Select a load to edit its name, "applies to", magnitude (psf), source, and notes in the right-hand inspector.
- Use the row menu to Duplicate or Remove a load.
Edits autosave — a "Saving… / Saved" badge confirms when the set is persisted. The code edition badge (e.g. the governing code edition) shows at the top of the page.
Dead-load assemblies#
A Dead load can be built from an assembly — a stack of material layers. Open the assembly editor from a dead load's inspector to compose layers; the resulting psf is the sum of the layer contributions and is computed for you rather than typed.
Why it's the single source of truth#
Because calcs reference criteria loads by id, changing a psf in Load Criteria flows downstream: a calc that linked to that load is flagged so you know its number changed. This keeps load values consistent across every member in the project. To understand how a psf becomes the line or point load a beam actually sees, read Area & Point Loads.