Convert DGN to BNA Online - Free & Fast

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.

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.

When Should You Use DGN vs BNA?

DGN vs BNA: Key Differences

• •The core technical difference: DGN relies on lossy compression whereas BNA uses lossy compression.
• •Neither format changes compression philosophy — both are lossy compression — so any size differences are due to encoding efficiency, not a shift in quality approach.
• •How transparency is handled: BNA does not support alpha channels — transparent areas in the source will become opaque.
• •Storage footprint: 100KB to 1GB depending on design complexity for DGN vs 1KB to 50MB depending on boundary complexity for BNA.
• •DGN is optimized for civil engineering, infrastructure mapping, transportation gis while BNA is designed for atlas gis boundary exchange, regional mapping, legacy spatial data conversion — choose based on your specific workflow needs

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.

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.

Common Use Cases for DGN to BNA Conversion

Industry Applications

Best Practices for DGN to BNA Conversion

• →When converting DGN to BNA: confirm the coordinate reference system (CRS / projection) is preserved or explicitly reprojected
• →Keep attribute tables and feature metadata intact — BNA should retain all fields from DGN
• →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 DGN to BNA Conversion

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

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