Building Definition Language

Structural Grids shall provide stable spatial references for structural members, Nodes, assemblies, Interfaces, and construction control.

A structural grid may contain:

linear grid axes;

radial axes;

reference planes;

control points;

modular intervals;

local subgrids;

vertical grid references.

Every grid axis shall define:

Grid Axis ID;

label;

geometry;

direction;

position;

parent coordinate system;

extent;

status;

tolerance where applicable.

Example:

structural_grid Main_Grid {

coordinate_system: @Building_CS;

axis A {

geometry: line([0 mm, 0 mm], [0 mm, 12000 mm]);

}

axis B {

offset_from: @A;

offset: 3600 mm;

}

axis 1 {

geometry: line([0 mm, 0 mm], [9600 mm, 0 mm]);

]);

}

axis 2 {

offset_from: @1;

offset: 3200 mm;

}

}

Grid labels shall be unique within their grid namespace.

A structural location may reference an intersection:

location: intersection(@Main_Grid.A, @Main_Grid.1, @Level_01);

Grid position and actual Component position shall remain distinct. A column may be intended to align with a grid intersection but have a measured As-Built offset.

BDL shall support:

primary structural grids;

façade grids;

service grids;

manufacturing grids;

Cartridge bay grids;

Changes to a controlling grid shall identify all dependent Entities and trigger geometric and engineering revalidation.