Preimage supported a residential project for NZD by validating actual built conditions against the BIM model used during construction. The objective was to assess how closely the completed space matched the intended design and identify deviations with greater clarity.

This required a structured workflow to verify built conditions, check spatial accuracy, and carry out deviation analysis confidently using reliable, measurable site data.

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The Challenge: Verifying Built Conditions Against BIM

Validating as-built conditions against BIM models can be challenging when workflows rely on manual checks and fragmented site information.

Key challenges included:

1. No clear and reliable verification workflow
Teams lacked a consistent way to validate built conditions against the BIM model

2. Dependency on physical site visits
With teams working remotely, repeated site visits were inefficient and time-consuming

3. Manual validation effort
Verification was time-consuming, prone to human error, and difficult to scale

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Solution: Digital As-Built Validation Workflow

Preimage created a streamlined workflow by capturing the residential space using a 360° camera and processing the data into a virtual tour and dense point cloud in under 3 hours.

This enabled a unified digital environment where teams could directly compare captured site conditions with the BIM model, validate dimensions, and identify deviations more efficiently.

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Deliverables

1. 3D Point Cloud

• Unified, high-accuracy 3D representation of the built environment
• Serves as the base for measurement, validation, and BIM comparison

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2. Accurate Measurements

• Enables precise measurement of distances, areas, and angles within the 3D environment
• Allows teams to validate dimensions accurately against the BIM model and intended design

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3. As-Built Comparison

• Aligns captured site data with the BIM model to identify layout and dimensional deviations
• Generates structured analytics and automated deviation reports for faster decision-making

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Results

Preimage enabled a more efficient and reliable approach to as-built validation by replacing manual workflows with a unified digital process.

Key Outcomes

• Improved verification efficiency by 40%
• Reduced dependency on repeated site visits
• Minimised manual validation effort and errors
• Enabled faster deviation analysis and reporting
• Provided a single workflow for BIM-based comparison

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By digitising site conditions and enabling direct comparison with BIM models, Preimage helped NZD streamline as-built validation, making it faster, more accurate, and easier to scale across residential projects.