> ## Content Index > Fetch the complete content index at: https://blog.topo-grapher.com/llms.txt > Use this file to discover other available public pages before exploring further. # Can BIM Models Retain Coordinates? Yes, If Set Up - URL: https://blog.topo-grapher.com/can-bim-models-retain-coordinates-yes-if-set-up/ - Published: 2026-10-18T07:48:02.000Z - Updated: 2026-10-20T19:18:45.000Z - Author: Aki Olafsson > Yes, BIM models retain coordinates. Where they lose them is in transit: a DWG exported without shared coordinates, an IFC written at the internal origin, a SketchUp model whose geolocation was never switched on. So the useful question is not whether a model can retain coordinates, but which exchange is about to drop them and how to check before it does. The usual cause is not the building geometry. It is a mismatch between the model’s internal origin, its project coordinate system and the real-world survey coordinates. So, can BIM models retain coordinates? Yes, but only when coordinates are deliberately established, preserved during exchange and checked whenever terrain, survey or consultant files enter the workflow. For architects and BIM coordinators, this matters as soon as the model needs to relate to a measured site. Levels, drainage falls, road alignments, utilities, landscape setting-out and civil information all depend on a consistent spatial reference. A model positioned arbitrarily may work for a planning image; it will create avoidable coordination work later. ## How BIM models retain coordinates A BIM model retains coordinates through two connected elements: a defined coordinate reference system and model settings that relate the project to it. The reference system identifies the real-world location, typically using eastings, northings and elevations. The model settings determine how its local geometry maps to those values. Most authoring applications also maintain a local working coordinate system. This is useful because large national grid values can cause display, precision or performance issues, particularly in detailed building models. The practical approach is therefore not always to model directly at full survey coordinates. Instead, keep the building close to a manageable local origin while assigning a reliable transformation to the survey grid. In Revit, this commonly means managing the Internal Origin, Project Base Point and Survey Point. The Internal Origin is fixed and should not be moved casually. The Project Base Point supports local project positioning, while the Survey Point represents the relationship to the shared survey coordinate system. Shared Coordinates allow linked consultant models to occupy the same physical location without every user modelling kilometres from the origin. The principle is similar in Archicad, Rhino, SketchUp and other tools, although the commands differ. The file must retain its local modelling logic and its documented relationship to the external coordinate reference. One without the other is incomplete. ## Retaining coordinates is not the same as displaying them A terrain viewer may show a site in the right place on a map, yet provide no usable coordinate information for your BIM workflow. Likewise, an imported DWG can appear aligned but carry an unknown origin, rotation or unit conversion. Visual agreement is not proof of coordinate integrity. A reliable model should allow a team member to answer three questions without guesswork: which coordinate reference system is in use, what is the elevation datum, and where is the model’s local origin relative to the survey grid? Record these decisions in the BIM execution plan, model notes or a simple project coordinate register. Vertical coordinates need the same care as horizontal ones. A value described as an elevation may refer to a local site datum, mean sea level, an orthometric height or an ellipsoidal height. If the architect’s terrain and the civil engineer’s survey use different vertical datums, a site can be correctly positioned in plan but wrong in height. That is enough to distort drainage studies, entrance thresholds and cut-and-fill assumptions. ## A practical setup for site-based BIM projects Start with the survey, not the building model. Request the coordinate reference system, units, benchmark information, northing and easting values, and the stated vertical datum. Do not assume that a drawing labelled as national grid is correctly georeferenced. Confirm it with the surveyor or civil engineer where the project depends on it. Next, establish a project control point. This should be a recognisable location with known coordinates, such as a survey station, grid intersection or defined site benchmark. Set the model’s shared coordinates from this control point, then verify a second point elsewhere on site. A single matching point can conceal an incorrect rotation or scale. Import or link survey information using the correct units and positioning method. In Revit, use linking rather than repeated imports where possible, and avoid moving a linked survey file manually to make it look right. If the link is wrong, correct the coordinate relationship at source or through a documented shared-coordinate workflow. Then create the terrain model from coordinate-aware elevation data. An XYZ file should contain easting, northing and elevation values in a known order and unit system. When these points are used to build a [Revit Toposolid](https://topo-grapher.com/topography-for-revit.html?ref=blog.topo-grapher.com), a SketchUp terrain mesh, an [Archicad Mesh](https://topo-grapher.com/topography-for-archicad.html?ref=blog.topo-grapher.com) or a Rhino surface, the terrain should sit in the same spatial framework as the building and survey. This is where clean source data saves time. Topo-grapher generates editable [XYZ terrain data](https://topo-grapher.com/learn/elevation-point-cloud.html?ref=blog.topo-grapher.com) from defined site boundaries, giving project teams a practical starting point for coordinate-aware terrain modelling rather than a visual surface with no dependable export path. ## Common reasons coordinates are lost Coordinates are often lost during model exchange rather than initial setup. Export settings may reset the origin, omit georeferencing metadata or convert units. A user may also relocate a model to make it easier to work with, then export it without preserving the transformation back to the survey grid. The most frequent issues are straightforward but costly: - A CAD survey is imported in millimetres when the BIM model expects metres. - True north and project north are confused, leaving the site rotated. - A terrain file uses a local datum while the consultant model uses national elevation values. - A linked model is moved manually instead of acquiring or publishing shared coordinates. - An IFC or DWG export is tested visually but not checked against known coordinate values. These problems do not always become obvious immediately. The building may appear correct in isolation. The conflict usually emerges when a civil surface, utilities model, landscape package or updated survey is linked later. ## Coordinate workflows by software ### Revit For Revit projects, set shared coordinates early and protect them. Link the survey or civil reference file, confirm units, then acquire or publish coordinates only when the agreed workflow is clear. Use the Survey Point to inspect and communicate real-world values. Keep an eye on point density when creating a Toposolid: an over-detailed surface can make the model slow without improving design decisions. When exporting, select shared coordinates where the receiving software requires real-world placement. Test the exported file by opening it independently and checking at least two known points. Autodesk's guidance is that all geometry should be within 10 miles or 16 kilometers of the model's internal origin ([Autodesk](https://help.autodesk.com/cloudhelp/2026/ENU/Revit-Model/files/GUID-3F79BF5A-F051-49F3-951E-D3E86F51BECC.htm?ref=blog.topo-grapher.com)), so keep geometry near the origin and let shared coordinates carry the real-world position. ### Rhino and Grasshopper Rhino is flexible with geometry but does not remove the need for coordinate discipline. Confirm document units before importing XYZ data, retain the point values where possible and document any local offset used to keep geometry near the origin. In Grasshopper, apply any offset transparently so that downstream users can reconstruct the original coordinates. ### SketchUp and Archicad Both applications can support site modelling effectively, but large-coordinate behaviour and import methods should be tested on the actual project file. Use a surveyed reference point, keep terrain and building geometry aligned, and retain a clear record of any translation or rotation. If exporting to consultants, verify the exported placement rather than assuming the source model’s location transfers automatically. ## When a local coordinate system is the better choice Not every project needs a full national-grid workflow. A small building alteration with no external civil coordination may be easier to manage in a local coordinate system, provided the survey uses the same system and the relationship to the wider site is documented. The risk increases when multiple disciplines, phases or adjacent sites are involved. For large sites, infrastructure schemes and masterplans, real-world coordinates are generally the safer default. They support phased surveys, repeated terrain updates and coordination across disciplines. The trade-off is that the team must agree the setup before modelling progresses. That short conversation is cheaper than repositioning every link after design development. ## Final check before issuing a model Before issuing a BIM model, check its coordinate reference system, units, rotation, elevation datum and two known survey points. Also check the exchange format itself: an IFC, DWG, CSV or geometry export may handle positioning differently from the native model. Coordinate retention is a controlled process, not a file property you can assume. Establish the reference early, keep terrain data traceable to it, and verify every handover. That gives the model a dependable relationship to the site when design decisions become more precise. > [Generate terrain with a known origin, free →](https://topo-grapher.com/?ref=blog.topo-grapher.com) ## FAQ **Does IFC export keep Revit's shared coordinates?** Only if the export is set to use shared coordinates. Check the IFC export setup and test with a known point before issuing. **How do I switch on terrain after importing a geolocation in SketchUp?** Add Location brings in a flat snapshot plus a hidden 3D terrain. Use File > Geo-location > Show Terrain to toggle between them. **How do I see the Z coordinate of a point in Archicad?** Place a Level Dimension or check the point in the Info Box; make sure the Project Zero and the survey reference level are set correctly first. **Can Rhino keep real-world coordinates?** Yes, but very large coordinates can cause display precision issues. Work relative to a local origin and record it. **Why does a linked model land in the wrong place?** Usually the two files have different survey points or one was moved manually. Link by shared coordinates and acquire coordinates from one agreed authority file. ## Further reading - [Autodesk: Link a DWG File and Acquire Its Coordinates](https://help.autodesk.com/cloudhelp/2026/ENU/Revit-Model/files/GUID-77BBFD78-8389-4FD4-8C95-929D92AAC590.htm?ref=blog.topo-grapher.com) - [BIM coordinates that keep terrain in place](https://blog.topo-grapher.com/bim-coordinates-that-keep-terrain-in-place/) - [Revit site georeferencing without coordinate drift](https://blog.topo-grapher.com/revit-site-georeferencing-without-coordinate-drift/) - [IFC terrain export for coordination workflows](https://blog.topo-grapher.com/ifc-terrain-export-for-coordination-workflows/)