The quick format decision
Do not buy CAD simply because it sounds more professional. Start with the task and the person who will use the file. A straightforward applicant may need only finished PDFs; a design team often needs editable mapping and a final PDF issue.
| Situation | Best starting point |
|---|---|
| Upload-ready location and block plans only | |
| Designer needs to edit, measure or coordinate mapping | DWG or DXF, plus final PDF |
| Consultant has specified a workflow | Match the requested CAD format, version, units and coverage |
| No software or design team | PDF rather than speculative CAD |
What PDF, DWG and DXF actually contain
A PDF is a page format that preserves an intended sheet layout, title block, boundaries, annotations and print size. It can contain crisp vector linework or a raster image, so the extension alone does not guarantee quality. DWG is a widely used native drawing format; DXF is an exchange format used between design applications.
CAD can contain editable geometry, named layers and mapped coordinates, but only if the supplier created and delivered it that way. Confirm the CAD version, units, origin, coordinate reference system and whether the file is georeferenced rather than assuming.
PDF and CAD compared
The same licensed map base can be issued in both formats. The difference is how it is handled, not a guarantee of extra surveyed accuracy.
| Factor | DWG / DXF | |
|---|---|---|
| Main role | Review, publication, printing and submission | Design, measurement and coordination |
| Editing | Treated as a fixed issued sheet | Editable geometry and layers |
| Scale | Defined at a stated paper size | Model geometry plotted at an output scale |
| Software | Browser or PDF reader | CAD or compatible design software |
| Portal use | Usually the clearest issue format | Do not assume raw files are accepted |
| Main risk | Compression, cropping or print resizing | Wrong units, layers, version, origin or accidental edits |
What the Planning Portal currently accepts
The Planning Portal's current upload list includes PDF, common image and Office formats, GML and HPGL .plt. It does not list DWG or DXF. Treat DWG and DXF as working files unless the receiving authority confirms that it accepts them, and issue an ordinary planning drawing as PDF.
The Portal also publishes a per-file limit. Check that limit and any different local authority rule immediately before submission; do not rely on an old upload checklist or package drawings into an unrequested archive.
How to turn CAD mapping into a final PDF
Agree the technical handover before the map is ordered, then retain the editable source and issue only controlled revisions.
- Confirm DWG or DXF version, units, coordinate system, coverage and required layers
- Check the map against site information and any measured survey
- Keep existing mapping, proposed work and annotation logically separated
- Add site address, plan title, number, revision, north, scale and scale bar
- Plot at the stated A4, A3 or agreed sheet size
- Open the exported PDF independently and check fonts, line weights, colours and scale
- Upload the issued PDF and retain the CAD source
Scale, coordinates and georeferencing
CAD geometry is normally drawn in real-world model units and then plotted at a chosen sheet scale. British mapping may be delivered in British National Grid coordinates, but a CAD file can also be moved near a local origin or supplied without reliable georeferencing. Ask rather than infer.
A planning PDF usually records the ratio scale and paper size but may not retain a usable coordinate reference system. A scale bar and written dimensions are therefore important final-document checks.
CAD does not replace a measured survey
OS MasterMap is a detailed topographic base, not a measured survey of the project and not a legal-boundary determination. Commission appropriate survey work when design or construction depends on exact boundary distances, building measurements, levels, drainage, trees, retaining structures or setting-out.
Final handover checklist
Before accepting files, make sure they are usable by the intended recipient and that the issued PDF is the same design revision as the CAD source.
- Correct site and map coverage
- Current licensed base data
- CAD version, units and coordinate basis recorded
- No missing external references, fonts or images
- Red and blue boundaries remain visible
- PDF page size and scale agree
- Scale bar measures correctly
- Drawing number, date and revision match the register
Local requirements may differ. Check the current validation list for your planning authority before submitting.
Evidence checked 18 August 2026
Official sources and further reading
Planning requirements differ across the UK. The scope label on each source shows where it applies; always use the current rules for the authority receiving the application.
Questions people also ask
Can I upload DWG or DXF directly to the Planning Portal?
Do not assume so. The current listed CAD upload type is HPGL .plt, not DWG or DXF. Issue PDF unless the receiving authority confirms another format.
Is CAD more accurate than PDF?
Not inherently. Both can come from the same source mapping. CAD gives editability and may preserve coordinates; neither becomes a measured survey merely because of its format.
Can an architect work from a PDF?
Sometimes, but tracing or converting a PDF can lose clean geometry, layers, coordinates and scale integrity. Ask the designer whether native DWG or DXF is required.
Do I need both CAD and PDF?
Often in a professional workflow: CAD for production and coordination, PDF for issue and submission. A simple homeowner map order may need PDF only.
Will a PDF remain to scale?
Yes when it is exported to the correct page size and printed at actual size. Verify the embedded sheet dimensions and measure the scale bar.
Ready to create your planning map?
Search by postcode or address, choose the scale and coverage, add your application boundary and download from UKPlanningMaps.com. For help with an unusual site, call 01856 898 022.
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