NDS 2018 · NDS 2024 · SDPWS · ACCA Manual J

Engineering Calculations

Wood design to the NDS & SDPWS, and mechanical HVAC loads to ACCA Manual J — every equation, substitution and code reference shown in full, with a printable calculation package.

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Choose your discipline

What are you calculating today?

Wood Design

Structural sizing to the AWC National Design Specification (NDS) and the Special Design Provisions for Wind & Seismic (SDPWS).

Beams, columns & combined loading
Diaphragms, shear walls & connections
Whole-building lateral force distribution

Explore wood tools → beta

Mechanical

Residential heating & cooling load calculations by the ANSI/ACCA Manual J method, with equipment sizing.

Whole-house or room-by-room loads
Design-condition & U-value libraries
Code-referenced, printable calc package

Open HVAC load calc →

Wood · NDS / SDPWS

Wood design tools

Individual calculators

Size a single beam, column, diaphragm, shear wall or connection with your own inputs — no project required.

Beam & column design
Diaphragm & shear wall (segmented / perforated)
Connections incl. Simpson hardware

Open calculators → beta

Building project

Lay out shear walls in plan on each floor, distribute story forces (rigid or flexible), then design every wall and diaphragm — all in one workspace.

Custom diaphragm shapes (rectangle, L, T, U, polygon)
Auto-uploads shear into a calculator per element
Toggle element tabs · 3D model of the finished building

Start a project →

Mechanical · ACCA Manual J

HVAC load calculation

beta

HVAC Load · Manual J

Build the envelope, choose design conditions, and get heating & cooling loads plus equipment sizing — the full calculation, step by step.

Whole-house or room-by-room scope
U-value, SHGC & design-condition libraries
Sensible / latent split, tons & supply airflow

Run a load calc →