Convert BNA to DGN Online - Free & Fast

What is BNA?

Atlas Boundaries (BNA) is a simple ASCII coordinate format for storing polygon boundary data, originally developed by Atlas GIS for representing area features like postal codes, sales territories, and administrative regions as coordinate lists.

What is DGN?

DGN (Design) is the native file format of Bentley Systems MicroStation, used for storing CAD drawings and GIS data in infrastructure projects such as roads, bridges, and utilities, supporting 2D and 3D design elements with level-based organization.

When Should You Use BNA vs DGN?

BNA vs DGN: Key Differences

• •BNA and DGN diverge on compression: lossy compression for the source, lossy compression for the target.
• •Since both BNA and DGN use lossy compression, the quality characteristics are comparable — differences in file size come down to how efficiently each format implements compression.
• •Transparency: N/A - binary format (V8 uses OLE2 container)
• •BNA files are typically 1KB to 50MB depending on boundary complexity while DGN files range 100KB to 1GB depending on design complexity
• •BNA is optimized for atlas gis boundary exchange, regional mapping, legacy spatial data conversion while DGN is designed for civil engineering, infrastructure mapping, transportation gis — choose based on your specific workflow needs

Advantages of BNA

• ✓BNA uses lossy compression tailored for Atlas GIS boundary exchange, regional mapping, legacy spatial data conversion.
• ✓BNA is supported natively on virtually every device, browser, and operating system.
• ✓BNA files are compact and quick to transfer, even over slow connections.
• ✓BNA integrates seamlessly with all major creative tools and workflows.

Advantages of DGN

• ✓DGN uses lossy compression tailored for Civil engineering, infrastructure mapping, transportation GIS.
• ✓DGN is supported natively on virtually every device, browser, and operating system.
• ✓DGN files are compact and quick to transfer, even over slow connections.
• ✓DGN integrates seamlessly with all major creative tools and workflows.

Common Use Cases for BNA to DGN Conversion

Industry Applications

Best Practices for BNA to DGN Conversion

• →When converting BNA to DGN: confirm the coordinate reference system (CRS / projection) is preserved or explicitly reprojected
• →Keep attribute tables and feature metadata intact — DGN should retain all fields from BNA
• →Check geometry types (point, line, polygon) map cleanly between the two formats
• →Verify that z/elevation values and topology survive the conversion when working with terrain data
• →Always keep a backup of your original files before converting
• →Choose the appropriate quality settings for your specific use case

Troubleshooting BNA to DGN Conversion

• !Topology errors in the converted DGN → self-intersecting polygons or duplicate vertices may not transfer cleanly between formats
• !The DGN file coordinate values shifted slightly → datums (WGS84 vs NAD83) differ even when the projection looks similar
• !Time field values were corrupted after converting BNA to DGN → date and time field formatting varies across GIS formats
• !Null geometry features appear in the converted DGN → empty or null-shape records in BNA may cause validation errors in some formats

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