How LAVA Supports Hybrid Designs for Both IRC and IBC to Produce Maximum Efficiency

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A common question we hear is: Can LAVA check the IRC? The short answer? LAVA supports mixed IRC (prescriptive) and IBC (engineered) wall design—within the same model. This hybrid approach allows engineers to optimize designs, streamline documentation, and save time on projects that blend prescriptive and engineered solutions.

For engineers working in residential wood design, the ability to efficiently blend IRC and IBC in a single model is a game-changer.

IRC Braced Wall Implementation in LAVA

The International Residential Code (IRC) provides prescriptive guidelines for residential construction, including braced wall lines for lateral stability.

Key constraints include:
Braced wall lines up to 60 feet apart in certain seismic zones
Braced wall panels placed within 10 feet of corners
Various bracing methods, including let-in bracing, gypsum board, and wood structural panels

LAVA enables users to designate certain walls as IRC braced walls directly within the model. However, users must manually qualify these walls—the software does not automatically check IRC constraints.

Workflow for Mixed IRC/IBC Designs

A hybrid IRC/IBC workflow allows engineers to model an entire building efficiently while incorporating prescriptive IRC elements. The process in LAVA looks like this:

  • Model the full structure, including all beams and gravity loads

  • Lay out all shear walls as part of the design

  • Identify IRC-qualified braced walls based on project constraints

  • Rename those walls (e.g., "GB" for gypsum board, "WSP" for wood structural panel)

  • Mark IRC walls to exclude from detailed calculations

  • LAVA distributes loads accordingly but does not generate detailed engineering reports for IRC braced walls

    This hybrid approach is especially useful for buildings that do not fully comply with IRC but can integrate both prescriptive and engineered elements for cost efficiency and code compliance.

Limitations:

While LAVA streamlines hybrid designs, some responsibilities remain with the user:
⚠️ Manual qualification of IRC walls – LAVA does not check IRC compliance
⚠️ Understanding of IRC tables and constraints – Engineers apply code requirements
⚠️ Ensuring correct wall designation – Proper marking avoids errors in load distribution

LAVA’s role is to enable a faster, more integrated approach—but final compliance remains with the designer.