3D Site Context for Architects: Data, Exports and Review Checklist

Start with the site boundary, surrounding building footprints, terrain, roads and the features that could affect the design. Record where each layer came from, when it was captured, its resolution and whether heights are measured, estimated or missing.

Keep existing context separate from proposed geometry. Label an assumed roof height as an assumption, not a surveyed dimension. A blank area in a dataset does not establish that the site is empty. Compare important features with current mapping, photographs and a site visit before relying on them.

The difference between a topographic survey and site analysis helps define the next appointment.

Choose the format for the receiving task, then test a small export in the intended application.

• GLB: useful for exchanging and viewing 3D geometry. Khronos defines glTF as an asset-delivery format; a successful export does not prove geospatial accuracy or preserve every lighting effect.
• OBJ or FBX: possible exchange choices for visualisation work. Confirm materials, axes, scale and geometry in the receiving application's supported version.
• IFC: an open exchange standard maintained by buildingSMART. Check the actual IFC entities and properties; exported reference geometry is not automatically editable native walls or a coordinated BIM deliverable.
• DXF: useful for a drawing handover where supported. Confirm drawing units, layer names and known distances after opening it.

Atlasly's export implementation includes these formats, but availability depends on the workflow and account. The SketchUp-oriented export produces a COLLADA .dae file; it is not a native .skp guarantee. Follow the site-context DXF handover guide and inspect the file you actually receive.

This is an illustrative quality check with invented dimensions, not a customer project or an Atlasly performance benchmark.

Assume the brief supplies a rectangular site 40 m by 60 m and a separately verified 20 m reference distance. The rectangle's area is 2,400 m². These are test inputs, not a claim about a real parcel.

1. Record the source, units, coordinate reference system, north direction and elevation datum alongside the original file.
2. Import the context into the receiving design application. Measure the 20 m reference. If it reads 20,000 while the file is interpreted as metres, stop and correct the unit interpretation before design work continues.
3. Check another known distance in a different direction and a known point location. Matching one distance alone does not prove the rotation or position is correct.
4. Keep an assumed 12 m neighbouring height visibly separate from surveyed heights. Compare the option with a 15 m sensitivity case to see whether that uncertainty changes the design discussion. Neither height is a site fact.
5. Show existing and proposed geometry separately. Mark missing terrain or roof detail in the view rather than filling gaps without explanation.
6. Reopen the final exported file and repeat the checks. Record the application/version and any lost elements.

A successful result is a documented, repeatable handover with unresolved items visible. It is not a certificate of survey accuracy.

A shadow view can help explain a design question if the date, time, location, orientation and height assumptions are recorded. An attractive rendering is not a validated daylight, sunlight or rights-of-light assessment. Agree the appropriate scope and method with the relevant specialist before using it for a formal conclusion.

For a design review, include the view location, existing/proposed legend, sources and outstanding checks. Avoid presenting estimated neighbouring geometry as measured evidence or promising that a view will secure planning support.

For each revision, record:

• Site name and boundary revision; existing/proposed status.
• Source publisher, capture date, download date and any licence conditions.
• Coordinate reference system, units, origin, north direction and elevation datum.
• Measured, estimated and missing heights or features.
• Export format, application/version and the scope of exported elements.
• Two checked distances, one checked location and the result of the reopen check.
• Known limitations, reviewer, review date and next required survey or assessment.

Keep this record with the drawing or site analysis report, so a later recipient can understand what the geometry supports.