LateralLogic is a visualization and decision-support tool that helps architects and structural engineers evaluate potential locations for lateral force resisting systems (LFRS) during the early stages of building design.

The tool is intended to promote earlier coordination between architectural planning and structural design by providing rapid feedback on the effectiveness of different braced frame locations within a conceptual structural grid. Architects can use the tool to better understand the structural implications of proposed layouts, while structural engineers can use it to communicate the importance of strategic LFRS placement early in the design process.

LateralLogic operates in two stages. In the first stage, every structural bay within a user-defined grid is evaluated independently using simplified structural heuristics for a single diagonal braced frame. The results are visualized directly within Dynamo and Revit, allowing users to quickly identify locations with greater structural potential.

In the second stage, users can select a group of bays to represent a proposed lateral force resisting system. The tool then evaluates the system as a whole using additional metrics that measure overall distribution and symmetry. These results provide quantitative feedback on how effectively the selected bays work together as a coordinated lateral system.

By combining visualization with simplified performance metrics, LateralLogic helps design teams make more informed structural decisions earlier in the design process while encouraging collaboration between disciplines.

Typical results can be seen in the two figures below. It is important to be careful when selecting number of bays in each direction, the distance must be divisibly by the number, otherwise the opportunuty for errors may arrise in some of the evalualtor equations. Both figures show very random LFRS placement to demonstrate how freeform the platform can be!

The organization of the Dynamo Logic is color coded to represent the functionality. If you want to learn more about what is going on in each box the title of each on says exactly what is being done within it!

• Pink → Inputs
• Cyan → Stage 1 (set up)
• Blue → Stage 2 (set up)
• Purple → Evaluation (both Stage 1 and Stage 2)
• Orange → Outputs or Visualizations

The intended users of this tool are structural engineers and architects collaborating during the early stages of building design. The tool is intended to support coordination between architectural planning and structural system placement by evaluating the effectiveness of lateral force resisting system (LFRS) locations within conceptual building massing studies.

Rather than focusing on detailed structural design, the tool supports conceptual decision-making, helping designers quickly understand which regions of a structural grid are more suitable for braced frame placement based on simplified geometric performance indicators.

Lateral force resisting systems are often introduced late in the design process, after architectural layouts and building massing have already been established. At this stage, structural systems are frequently constrained by architectural decisions, leading to inefficient placement, increased material usage, and suboptimal lateral performance.

This disconnect can result in poor torsional behavior, limited system efficiency, and conflicts between structural requirements and architectural intent.

My tool fill the need for a rapid, early-stage feedback tool that allows designers to evaluate the suitability of potential LFRS locations during conceptual massing development, rather than after design decisions are fixed.

This tool addresses that need by providing immediate, geometry-based feedback on the effectiveness of braced bay locations within a structural grid.

The tool is a parametric design assistant developed in Dynamo for Revit that evaluates the suitability of potential lateral force resisting system (LFRS) locations within a conceptual building grid.

The system functions in two stages:

Stage 1: Individual Bay Evaluation

The tool generates a structural grid based on user-defined building dimensions and bay spacing. Each structural bay is evaluated independently as a potential location for a single diagonal braced frame using simplified geometric performance metrics.

Stage 2: System Evaluation

The user can select a group of bays to form a complete lateral system. The tool then evaluates the overall configuration to assess system-level behavior using simplified distribution and symmetry-based metrics.

The tool is intentionally simplified and relies on geometric heuristics rather than full structural analysis, enabling fast feedback during conceptual design.

Slider Inputs

• Building Length (ft) – X direction
• Number of Bays Along Length
• Building Width (ft) – Y direction
• Number of Bays Along Width
• Floor Height (ft)
• Number of Floors

User Interface Inputs

• Selection of structural bays for group evaluation (Part 2 extension)

1. Grid Generation

• A parametric structural grid is generated in Dynamo based on input dimensions.
• Nodes and bay boundaries are created to define potential braced frame locations.

2. Center of Mass Calculation

• The building is assumed to have uniform mass distribution.
• The center of mass is located at the geometric center of the plan.

3. Creation of Bay List and User Selection

• A list of all structural bays is generated.
• The user can select bays through a UI for system-level evaluation in the extension stage.

Stage 1: Individual Bay Evaluation

Each structural bay is evaluated independently using two geometric heuristics and then the two are averaged to give the value for visualizations.

1. Brace Efficiency (Geometry-Based)

• Evaluates the angle of a potential diagonal brace within the bay.
• Braces closer to 45° are considered more efficient.

2. Torsional Leverage (Moment Arm)

• Measures the distance between the bay location and the center of mass.
• Bays further from the center are considered more effective in resisting torsional effects.

Stage 2: System Evaluation

Users can select multiple bays to form a proposed lateral force resisting system. The tool evaluates the overall configuration using two system-level metrics:

1. Distribution Balance

The number of selected bays is compared across the X and Y directions.

A balanced system is preferred, as it indicates more uniform lateral resistance.

• Balanced X/Y distribution → good performance
• Highly skewed distribution → poor performance

2. Eccentricity (Center of Rigidity Approximation)

A simplified center of rigidity is computed using the geometric locations of selected bays (assuming equal stiffness).

The eccentricity between the center of rigidity and center of mass is calculated.

Smaller eccentricity indicates:

• more symmetric system behavior
• reduced torsional irregularity
• improved overall balance of lateral resistance

Stage 1 Outputs

• Color-coded bays based on individual suitability score in both Revit and Dynamo

Stage 2 Output

• Numeric distribution balance score
• Numeric eccentricity score
• Visual representation of selected system layout in both Revit and Dynamo color coded to individual bay score (not overall system score)

The project was developed iteratively, beginning with the generation of a parametric structural grid and the implementation of individual bay evaluation metrics. Once the foundational scoring system was established, the workflow was extended to include a user interface for selecting multiple bays and evaluating them as a collective system.

The final stage of development focused on integrating system-level evaluation metrics, including distribution balance and a simplified center of rigidity calculation. This allowed the tool to move from evaluating individual structural opportunities to assessing the behavior of complete lateral systems within a conceptual building layout.

Future development may include refinement of the scoring weights, additional structural heuristics, and expanded support for more complex lateral system configurations.