Ordnance Survey Digital Terrain Model (DTM) 5m Grid Topographic Points with Optional Contours - Email delivery in 20 minutes

Q: What is the difference between DXF and DWG formats?

DWG is Autodesk’s proprietary binary format, designed for full compatibility with AutoCAD and Revit. DXF is a universal, text-based format widely compatible with most CAD and GIS software, including AutoCAD, Revit, QGIS, ArcGIS, and Civil 3D.

Vector Format OS Height layer in DWG | DXF for CAD software

Ordnance Survey Premium Licenced Partner • 2D or 3D Optional Contours available • Option to add OS vector base mapping

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OS Terrain 5 DTM grid points displayed in AutoCAD with properties panel showing X Y and Z coordinate values for each 5-metre post

Close-up of OS Terrain 5 grid points with blue elevation values and red contour lines generated from the 5-metre height model

Colour-shaded terrain relief of Highland mountains lochs and valleys with orange shading and contour lines derived from OS Terrain 5

Black contour lines on white background showing detailed mountain and valley terrain generated from OS Terrain 5 height data

Hillshaded DTM relief rendering showing three-dimensional grey terrain visualisation created from OS Terrain 5 ASCII grid data

OS Terrain 5 DTM grid points with blue elevation values and red contour lines showing a gently undulating terrain area

Artistic layered contour visualisation with brown and orange shading showing a valley cross-section derived from OS height data

OS Terrain 5 grid points with blue height values and pink contour lines showing relatively flat terrain with gentle elevation changes

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OS Terrain 5 DTM points loaded into AutoCAD - each post carries X, Y coordinates and a Z elevation value on the British National Grid. DTM grid with blue elevation labels and red contour lines - contours generated at your chosen interval from the 5-metre height model. Colour-shaded terrain relief built from OS Terrain 5 ASCII grid data - ideal for landscape assessment, flood modelling and visual impact studies. Contour-only output on a clean white background - ready for overlay onto site plans, engineering drawings or planning submissions. Hillshaded 3D terrain surface rendered from the OS Terrain 5 digital terrain model in a GIS environment. DTM grid points combined with generated contour lines - showing how the 5-metre posts translate into smooth, usable contour geometry. Layered contour visualisation with elevation shading - the same OS height data styled for presentation and report graphics. Terrain 5 height points on relatively flat ground - the 5-metre grid captures subtle elevation changes that matter for drainage and earthworks design.

Download DTM Samples

DTM Only

DWG | DTM Points ↓ DXF | DTM Points ↓

Contours Only

DWG | 2m Contours ↓ DXF | 2m Contours ↓

All Layers (DTM + Contours + MasterMap)

DWG | All Layers ↓ DXF | All Layers ↓

ASCII Grid

OS Terrain 5 ASCII ↓

OS Terrain 5 - Digital Terrain Model with Optional Contours

Ordnance Survey Terrain 5 is a 5-metre resolution digital terrain model covering the whole of Great Britain. Every grid post carries an X, Y coordinate on the British National Grid and a Z elevation value in metres above Ordnance Datum (Newlyn). We deliver the data as DWG or DXF for immediate use in AutoCAD, Civil 3D, BricsCAD and all major CAD platforms - or as an ASCII grid file for GIS, surface modelling and 3D visualisation workflows.

Why Order Height Data from UK Map Centre?

Ordnance Survey supplies OS Terrain 5 as an ASCII grid - a raw text file of elevation values arranged on a 5-metre grid. That format works well in GIS software and surface modelling tools, but it cannot be opened directly in AutoCAD or other CAD packages. We solve that by converting the ASCII grid into clean DWG and DXF geometry with every height point placed at its correct X, Y, Z position - ready to snap, measure and build on the moment you open the file.

CAD-Ready DTM Points

Every 5-metre grid post placed as a 3D point or block at its true OS National Grid position with the Z value set to metres above sea level. Open the file in AutoCAD and your terrain surface is already there - no import wizards, no coordinate conversion, no guesswork.

Contours at Your Interval

OS supplies contours only at 5-metre intervals. We generate contour lines from the raw grid at 0.5m, 1m, 2m or 5m spacing - true 3D polylines with Z values in every vertex, placed on a dedicated CAD layer ready for earthworks calculations and cross-sections.

ASCII Grid for GIS & 3D

Need the raw elevation grid? We supply the OS Terrain 5 ASCII file trimmed to your site area or as the full 5km x 5km tile - ready for import into QGIS, ArcGIS, Global Mapper, Civil 3D or any surface modelling application that reads ASC format.

Bolt-On: MasterMap Base Mapping

Add OS MasterMap Topography Layer as a base map underneath your terrain data. Buildings, roads, boundaries and vegetation on named CAD layers - giving your height model the context it needs for site design, planning and analysis.

Updated quarterly - OS Terrain 5 is refreshed every three months (January, April, July, October), so your elevation data reflects the latest survey revisions.

Flexible coverage - order exactly the area you need, from a single field to an entire catchment. The data is clipped to a rectangular extent or a custom site boundary and delivered by email or download link.

Who Uses OS Terrain 5?

Height data underpins a wide range of professional workflows. Architects and engineers use the DTM for site grading, cut-and-fill calculations and foundation design. Civil engineers model drainage paths, flood risk zones and road gradients. Environmental consultants run viewshed analysis, landscape character assessments and visual impact studies. Renewable energy planners assess wind exposure and solar shading. Forestry managers map slope gradients for harvesting plans. Utility companies route pipelines and cables across terrain profiles.

Contour Intervals Explained

A 0.5-metre contour interval captures fine terrain detail for earthworks, drainage design and level surveys. A 1-metre or 2-metre interval suits site-wide grading plans and planning submissions. The standard 5-metre interval is useful for regional landscape assessment, viewshed analysis and route planning across larger areas. All contour intervals are derived from the underlying 5-metre OS Terrain 5 grid - the tighter intervals interpolate between the original height posts to produce usable contour geometry for guideline and planning purposes.

Delivery Formats

Choose the format that fits your software and workflow:

DWG - native AutoCAD format with full layer support, best for Autodesk workflows including Civil 3D and Revit
DXF - universal CAD exchange format, opens in AutoCAD, BricsCAD, MicroStation, LibreCAD and virtually every CAD application
ASCII Grid (.asc) - raw elevation grid for GIS analysis, surface modelling and 3D terrain rendering in QGIS, ArcGIS, Global Mapper and FME

All CAD files are georeferenced to the British National Grid (EPSG:27700). The DWG and DXF outputs include DTM points on one layer and contour lines (if selected) on a separate layer - so you can toggle terrain and contours independently.

CAD Software Compatibility

AutoCAD by Autodesk
Civil 3D
BricsCAD
MicroStation
Draftsight
LibreCAD
Global Mapper (ASCII grid import)
QGIS (ASCII grid and contour shapefile)
ArcGIS (ASCII grid raster surface)
… all CAD packages that read DWG or DXF

About UK Map Centre LLP

UKMapCentre.com is a sustaining member of QGIS — QGIS Supporter

UKMapCentre.com is a member of The Association for Geographic Information — AGI Member

Alternative Products:

OS MasterMap for CAD 3D OS MasterMap with Building Heights Extracts: PDF | JPG | TIFF - 1:1250

Product:	OS Terrain® 5 - Height Data - Contours and DTM - DXF or DWG
Base Mapping	Option to add: OS Mastermap in DWG and DXF
Scale	Variable set within your CAD or GIS software
Coverage	Full Great Britain coverage (sorry this excludes Northern Ireland - see OSNI)
Format	DXF, DWG, CAD, Geopackage, GML, ASCII Grid, Shapefile
Software Required	CAD (e.g. AutoCAD, Civil 3D) or GIS (e.g. QGIS, ArcGIS Pro)
Product Price	From: £12.50 + vat
Delivery Method	Digital delivery by email
Turnaround Time	Email: Target time of 20 mins (7 days a week 7am to 11pm) - Larger files may take longer to generate
Currency	Current - Latest available direct from Ordnance Survey
Samples	Click here to download a sample - DTM Layer Only \| DXF Click here to download a sample - DTM Layer Only \| DWG Click here to download a sample - Contours Layer Only \| DXF Click here to download a sample - Contours Layer Only \| DWG Click here to download a sample \| OS Basemap with DTM and 2m Contours \| DXF Click here to download a sample \| OS Basemap with DTM and 2m Contours \| DWG
Key Features	Z value on the DTM points for 3D Modelling Product Georeferenced - UK Grid
Uses	Topographic map creation, CAD planning, GIS visualisation
Number of Printouts	Unlimited outputs from CAD within the selected licence term (1, 2 or 3 years)
3D Modeling	Our recommendation is to simply purchase the DTM data. The contours are designed to provide a 2 dimensional guideline only. For 3D modeling it is best practice to use the DTM points as they have an X,Y and important Z(height) value attached to them
Options Info	For 3D use, we recommend the DTM data. It contains X, Y and important Z(height) values for accurate terrain modelling. Contours are 2D only and best used for visual reference.
GIS Tiles	OS Terrain 5 is also available as Shapefile Contours - GML Contours - ASCII Grid OS T5 5km x 5km Tiles or Smaller areas/data chunks
Licence Term	Please go to the Licence tab below
Accuracy	OS Statement: OS Terrain 5 has been measured against with GPS points in a range of sample areas to provide a root mean square error (RMSE) value for the height points in each geographic area; urban and major communication routes, rural, and mountain and moorland. Urban and major communication routes = 1.5 metres RMSE* Rural = 2.5 metres RMSE Mountain and moorland = 2.5 metres RMSE * Root mean square error. This is the average of the mean heights collected in a sample area. The contours are generated from the OS Terrain® 5 using a third party application. They are not subject to Ordnance Surveys accuracy / specifications and are designed to provide a 2 dimensional guideline only.
Further Reading	OS Terrain 5 User Guide \| OS Doc

Item	Permitted	Alternative Product / Notes
GIS Use		We would recommend using Shapefile Contours \| GML Contours \| ASCII Grid 5km x 5km Tiles or for smaller areas ASCII Sections
Ready for CAD		Data already georeferenced for AutoCAD, Revit, Civil 3D, etc.
Printing Extra Copies		Unlimited outputs/scales from your software within the licence term
Contours Note		Contours are generated from the OS Terrain® 5 using a third party application. They are not subject to Ordnance Surveys accuracy / specifications and are designed to provide a 2 dimensional guideline only.
Permit your Contractors to use the purchased Licensed Data		Contractor Form Below - Best Practice: Make sure you select the relevant number of users/terminals if using a contractor before purchase

FREQUENTLY ASKED QUESTIONS

What is the difference between DXF and DWG formats?

DWG is Autodesk’s proprietary binary format, designed for full compatibility with AutoCAD and Revit. DXF is a universal, text-based format widely compatible with most CAD and GIS software, including AutoCAD, Revit, QGIS, ArcGIS, and Civil 3D.

Can I reuse the same CAD map for multiple planning applications?

Yes. Our extended licence allows you unlimited use from the same height map during your licence term. Ideal for submitting revised plans or topographical mapping across multiple applications.

How do OS MasterMap DXF/DWG formats differ from GIS formats?

The DXF and DWG formats are CAD-ready extracts designed for fast integration and visual clarity. Unlike GIS formats (such as GeoPackage, GML, or Shapefile), they omit GIS-level metadata and styling. This makes them ideal for clear CAD visualisation, basic mapping tasks, and site planning, while GIS formats deliver detailed spatial analysis and advanced GIS workflows.

What formats are available for OS Height Data DTM from the UK Map Centre?

Available in DWG and DXF formats, for CAD, or in GIS formats such as ASCII Grid, GML, or Esri Shapefile. Please refer to our dedicated OS Terrain GIS Tiles page. For smaller ASCII sections, see our OS Terrain GIS page tailored for GIS workflows. DTM tiles can also be requested in smaller chunks for location-based mapping or download.

How accurate are the contour lines provided in DXF or DWG format?

Contour lines included with OS Height Data DTM are derived from OS Terrain® 5 - They offer useful elevation context but are not OS-certified. For best results, use DTM data points for accurate land height map creation.

If your project demands official Ordnance Survey-approved contour data, particularly for detailed GIS analysis or precise 3D modelling, consider our OS Terrain 5m Grid & Contours Tiles, fully suitable for advanced terrain visualization [visualisation] and accurate spatial analysis.

Can I combine OS Height Data DTM contours with OS MasterMap CAD data?

Yes, you can combine contour layers with OS MasterMap features to enhance context and terrain modelling. This creates a more complete contour map suitable for planning and presentation. We'll supply your combined file ready to download and use.