StudWall Calculator

A simple yet powerful Python tool for the structural analysis and design of light-frame wood stud walls based on the CSA O86-20 standard and loads from the National Building Code of Canada (NBCC) 2020.

This calculator automates the process of sizing studs for multi-story buildings by calculating cumulative axial loads and performing design checks for all valid lumber sizes, spacings, and ply combinations.

Overview

The primary goal of this project is to provide engineers, designers, and students with a transparent and easy-to-use tool for stud wall design. The calculator takes basic architectural and loading information as input and iterates through a comprehensive set of design options to find the most economical solution for each floor level.

The core features include:

• Unit System Flexibility: Supports both Metric and Imperial units for inputs and outputs.
• Cumulative Load Calculation: Automatically calculates and accumulates dead, live, and snow loads from the roof down to the foundation.
• Comprehensive Design Checks: Performs compressive resistance calculations according to CSA O86-20, including all relevant modification factors (k-factors).
• Optimal Solution Finding: Identifies the most efficient design for each level based on a wood volume proxy.
• Clear & Detailed Output: Presents all valid solutions and highlights the optimal choice for each floor, along with detailed calculation results.

How to Use

To run the calculator, simply configure the inputs in the main.py script and execute it from your terminal.

1. Configure Inputs

Open main.py and modify the following sections:

Choose the Unit System: Select either Units.Metric or Units.Imperial.

# --- CHOOSE YOUR UNIT SYSTEM HERE ---
# units = Units.Metric
units = Units.Imperial

Define Building and Load Parameters: Update the inputs dictionary with your project's specific values. Ensure the values correspond to the chosen unit system (e.g., feet and psf for Imperial, meters and kPa for Metric).

# --- DEFINE YOUR INPUTS HERE ---
inputs = {
    "wall_heights": [10, 10, 10, 10, 12],  # ft or m
    "spacings": [16, 12, 8],              # in or mm
    "plys": [1, 2, 3],                   # number of stud plys
    "roof_dead": 22,                     # psf or kPa
    "roof_snow": 69,                     # psf or kPa
    "floor_dead": 35,                    # psf or kPa
    "floor_live": 40,                    # psf or kPa
    "partitions": 20,                    # psf or kPa
    "wall_sw": 12,                       # psf or kPa (wall self-weight)
    "wall_roof_trib": 2,                 # ft or m
    "wall_floor_trib": 11,               # ft or m
}

2. Run the Script

Execute the script from the root directory of the project:

python main.py

The script will print a detailed report for each floor level, showing all valid design solutions and highlighting the most economical one.

Project Structure

The project is organized into the following directories and files:

.
├── main.py                     # Main entry point for running the calculator
├── src
│   ├── core
│   │   ├── calculator.py       # Core logic for the StudWallCalculator class
│   │   ├── results.py          # Defines the DesignResult data structure
│   │   └── units.py            # Handles unit conversions
│   │
│   ├── data
│   │   └── joist_and_plank.csv # Database of wood material properties
│   │
│   └── models
│       ├── O86.py              # Implements calculations from the CSA O86-20 standard
│       ├── section.py          # Defines the Section class for structural members
│       ├── wood.py             # Base class for wood materials
│       └── joist_and_plank.py  # Specialization of the Wood class
│
└── README.md                   # This file

License

This project is licensed under the MIT License. See the LICENSE file for details.