Interior vs Exterior Scanning: Different Tools for Different Jobs

Why Interior and Exterior Scanning Are Fundamentally Different

If you've ever tried to use a terrestrial laser scanner (the kind on a tripod) to scan a building interior, you know the frustration. It's slow, requires multiple setup positions, and struggles with tight spaces and furniture.

Conversely, if you've tried to use a handheld LiDAR scanner for an exterior building survey, you've probably discovered accuracy issues, range limitations, and weather sensitivity.

That's because interior and exterior scanning are fundamentally different jobs that require different tools, workflows, and expertise. Understanding these differences is crucial for choosing the right scanner and getting the best results.

This article breaks down the key differences, which tools work best for each scenario, and when to use which approach.

Interior Scanning: Requirements and Challenges

Interior scanning is all about speed, portability, and navigating complex spaces. Here's what makes it unique:

Key Requirements

• Speed: Need to scan entire buildings quickly—often multiple floors in a single day
• Portability: Must navigate through doorways, up stairs, around furniture
• Close-range accuracy: Need precise measurements for walls, doors, windows (typically 1-3cm accuracy is sufficient)
• Furniture handling: Must work around existing furniture, equipment, and occupants
• Low light tolerance: Interiors often have poor lighting compared to exterior scans

Common Challenges

• Tight spaces: Narrow hallways, small rooms, cluttered areas
• Multiple floors: Need to scan vertically as well as horizontally
• Occupied buildings: People and moving objects create noise in point clouds
• Complex geometries: Non-orthogonal walls, curved surfaces, irregular room shapes
• Reflective surfaces: Glass, mirrors, polished floors can cause scanning issues

Best Scanners for Interior Work

Handheld and mobile LiDAR scanners excel at interior scanning:

Exterior Scanning: Requirements and Challenges

Exterior scanning prioritizes accuracy, range, and environmental resilience. Here's what makes it different:

Key Requirements

• Long range: Need to capture building facades, entire structures from distance
• High accuracy: Survey-grade precision often required (sub-centimeter for as-built documentation)
• Weather resistance: Must work in rain, wind, varying temperatures
• GPS integration: Often need georeferenced data for large-scale projects
• Large coverage: Need to scan entire building exteriors, sites, or multiple structures

Common Challenges

• Weather conditions: Rain, fog, wind can affect scan quality
• Sunlight: Bright sunlight can interfere with laser measurements
• Large distances: Need to capture details from 50-300m away
• Multiple scan positions: Require careful registration and alignment
• Traffic and safety: Working near roads, construction sites, public areas

Best Scanners for Exterior Work

Terrestrial laser scanners (TLS) dominate exterior scanning:

Comparison: Interior vs Exterior Scanning

When to Use Which Tool: A Decision Framework

Use this framework to choose the right scanning approach:

Our Honest Limitations: Why ScanToBIM-CAD is Optimized for Interior Scans

At ScanToBIM-CAD, we're transparent about what we do well and what we don't. Here's the honest truth:

What We Do Best

Alternative Tools for Exterior Scanning Workflows

If you're doing exterior scanning work, here are tools better suited for those projects:

Point Cloud Processing Software

• CloudCompare: Free, open-source point cloud processing. Excellent for registration, cleaning, and analysis of large exterior scans.
• Autodesk ReCap Pro: Industry standard for point cloud registration and processing. Required for importing into AutoCAD/Revit.
• Leica Cyclone: Professional software for Leica scanner data. Best for complex registration and georeferencing.
• Faro Scene: Native software for Faro scanners. Excellent for exterior scan processing and registration.

CAD/BIM Software for Exterior Work

• AutoCAD with CloudWorx: Plugin for working with large point clouds in AutoCAD. Best for facade documentation.
• Revit with Point Cloud Tools: Native point cloud support in Revit. Good for creating 3D models from exterior scans.
• Bentley Pointools: Specialized software for large-scale point cloud visualization and modeling.

Hybrid Approaches: Combining Interior and Exterior Data

Many projects require both interior and exterior documentation. Here's how to combine the two approaches:

Workflow Example: Complete Building Documentation

1. Exterior scanning: Use terrestrial scanner (Faro, Leica) to capture building facades, site context, and exterior details. This provides georeferenced, high-accuracy exterior data.
2. Interior scanning: Use handheld LiDAR (GeoSLAM, BLK2GO) to quickly capture interior floor plans. This provides fast, portable interior documentation.
3. Registration: Align interior and exterior point clouds using common reference points (doorways, windows, building corners).
4. Processing: Use ScanToBIM-CAD for interior floor plans, and specialized tools (ReCap, CloudCompare) for exterior facade documentation.
5. Integration: Combine both datasets in your CAD/BIM software to create comprehensive as-built documentation.

This hybrid approach gives you the best of both worlds: fast interior documentation and high-accuracy exterior data.

Best Practices for Each Scanning Type

Interior Scanning Best Practices

• Walk at consistent speed: Handheld scanners work best with steady, consistent movement
• Overlap your paths: Walk through each room multiple times from different angles to ensure complete coverage
• Close doors: Helps with room boundary detection and reduces point cloud noise
• Minimize moving objects: Ask occupants to stay still during scanning when possible
• Scan vertically: Include ceiling and floor in your scanning path for better 3D reconstruction

Exterior Scanning Best Practices

• Plan scan positions: Pre-plan your scan positions to ensure complete coverage and good overlap
• Use targets: Place reflective targets for easier registration between scan positions
• Check weather: Avoid scanning in rain, fog, or extreme sunlight
• Georeference early: Set up GPS/GNSS control points at the start of the project
• Document conditions: Note weather, lighting, and any obstructions that might affect scan quality

Conclusion: Choose the Right Tool for the Job

Interior and exterior scanning are fundamentally different jobs that require different tools and approaches:

• Interior scanning: Handheld LiDAR excels—fast, portable, perfect for floor plans
• Exterior scanning: Terrestrial scanners dominate—high accuracy, long range, weather-resistant
• Hybrid approach: Use both for complete building documentation

At ScanToBIM-CAD, we're optimized for interior scans because that's where we can deliver the most value. Our AI models are trained on interior data from handheld scanners, and we achieve best results for floor plan extraction from interior point clouds.

If you're doing primarily exterior work or need survey-grade precision, specialized tools designed for those use cases will serve you better. But for interior as-built documentation and floor plans, we're the fastest and most cost-effective solution.

Ready to optimize your interior scan-to-CAD workflow? Try ScanToBIM-CAD free and convert your interior point clouds to floor plans in minutes. No credit card required.

Want to learn more? Check out our guides on handheld LiDAR floor plans and Faro scanner workflows.