Building Definition Language

1. Introduction

System05 requires a formal language through which a complete building can be described as an integrated engineering system rather than as a collection of disconnected drawings, schedules, specifications, spreadsheets, models, and manufacturer documents.

Traditional construction information is distributed across multiple discipline-specific representations. Geometry may exist in a BIM model, structural requirements in calculations, equipment data in schedules, Interface conditions in details, control logic in software, and lifecycle information in separate asset-management systems. These representations frequently use inconsistent identities, units, assumptions, and revision histories.

Building Definition Language, or BDL, provides a unified, declarative, machine-readable representation of the building.

BDL shall describe:

what the building contains;

where each entity is located;

how entities are connected;

what each entity provides and requires;

which Engineering Profiles apply;

which constraints must be satisfied;

which configurations are proposed, approved, installed, or operational;

what evidence supports each engineering claim;

which information remains unknown or unresolved.

BDL shall allow the same building definition to be interpreted by:

engineers;

architects;

manufacturers;

the Engineering Compiler;

Building BIOS;

Digital Twins;

AI systems;

manufacturing systems;

robots;

inspection and maintenance tools.

BDL shall not replace drawings, calculations, simulation models, or human-readable specifications. It shall provide the structured semantic framework through which these resources are identified, related, validated, and traced.