How to Export Site Context to DXF for AutoCAD Using Atlasly

Download the synthetic DXF sample and sample notes. It contains a building outline, a road line exactly 100 metres long in the exporter’s local frame, a tree point, a contour at 25 metres and an invented constraint outline. All features are illustrative.

Open the file in your CAD package, confirm metres, and measure the line on A-ROAD-PRIMARY from approximately (−50, −30) to (50, −30). It should measure 100 drawing units. Inspect the named layers and contour height. The file has been checked against the exporter’s output; opening it in your particular CAD version remains a handover check.

The current drawing controls support British National Grid (EPSG:27700) or local metres, recorded in the drawing frame. Inspect the chosen setting and the export notes. The synthetic sample below deliberately uses the local frame: X runs east, Y north, and the origin is the selected extent centre.

British National Grid conversion uses a seven-parameter Helmert transformation, not OSTN15. The exporter records its alignment limitation; verify against measured survey control before design use. It is not for setting out. Local coordinates are not national-grid eastings and northings; assigning a grid in CAD does not transform them. Keep the original file and record the coordinate setting and any reviewed alignment.

This reference describes the Atlas AI project map’s Site Context DXF download. Names below are the default delivered CAD layers; practice layer-name overrides can change them. Internal map categories such as building and contourMajor are not the delivered names. Layers depend on available geometry and export settings. A missing layer does not show that its real-world feature is absent.

Layer or group	Contents when available
A-BLDG	Building outlines; height or a default height may be applied as thickness
A-ROAD-*	Roads, paths or rail geometry by class
A-WATER / A-WATERWAY	Water outlines or lines
A-GREENSPACE / A-TREE	Green space outlines or tree points
C-TOPO-MAJOR / C-TOPO-MINOR	Contour geometry with source elevation; major/minor follows the source index flag
A-CONST-*	Available constraint geometry routed to its named layer
A-DATA-SOURCE-INFO	Source notes when supplied with the export
A-ANNO-*	Grid, scale bar, north arrow and title annotations

This route does not emit a separate C-TOPO-TEXT contour-label layer. Read contour elevation from the line geometry in the receiving application. The project boundary, when supplied, is on A-SITE-BNDY; A-ANNO-EXTENT records the selected export extent separately.

Polygons are outlines rather than guaranteed filled areas. Do not infer contour interval, vertical accuracy, a listed building’s curtilage or a complete constraint search from the layer name alone.

Locate the site and confirm the area intended for the export. Review which layers have loaded and whether their sources and dates are suitable. A visible map is not proof that every underlying feature is present in the exported file.

Keep ownership boundaries, planning application boundaries and a user-drawn study area distinct. A terrain or building dataset is not a measured topographic survey. Mapped heritage records do not establish the legal curtilage of a listed building.

Open the site project in Atlas AI and choose Export map & data. In the Export site context panel, set Format to DXF where offered. Check the account entitlement and the formats and settings actually shown. Retain any export summary, source information, coordinate setting and warnings.

Do not assume a fixed layer inventory, contour interval or delivery time. If a layer is missing or a file is unexpectedly small, inspect the result and source coverage before continuing. The presence of a successful download alone is not a quality check.

Open a copy in the target CAD application. Confirm the drawing units and compare a known dimension. Inspect the origin and coordinate system; local planar, latitude/longitude and projected coordinates are not interchangeable. Do not assume every export is British National Grid merely because the site is in Britain.

Before combining the context with survey or consultant information, establish the agreed coordinate reference and any transformation. Check at least two identifiable locations as well as scale and orientation. Keep the original export unchanged so subsequent transformations are traceable.

Review the layer list and turn layers on separately. Check the site extent, closed boundaries, overlapping lines, building footprints and any elevation information. Confirm that expected context appears in the file and that labels correspond to the intended features.

Use separate layers for indicative context and verified survey information. Label limitations in the drawing package, especially where map boundaries or estimated heights could be mistaken for measured evidence. Avoid tracing a planning buffer as a definitive legal extent.

Record the export date, site boundary, format, coordinate settings and checks performed. Identify unresolved discrepancies and the survey information that will replace early context. If the site area or source data changes, issue a revised context reference rather than silently overwriting the old drawing.

The workflow can support early AutoCAD drafting, but compatibility with a particular version, imported entity type or other CAD application should be tested on the actual file. See Atlasly’s methodology and limits for the evidence boundary.