When you send CAD files, you are rarely sending one file. A drawing references xrefs, images and fonts; a Revit model links other models and CAD files; a SolidWorks assembly is a tree of parts. Each of those links is a file path. Change the folder layout on the way, and the recipient opens a drawing full of missing references. This guide shows how to package a project so the paths survive, and how to send CAD and BIM files as one intact folder.
Why does folder structure matter for CAD files?
Every major CAD and BIM tool stores references as paths:
| Software | What is referenced | How the path is stored | Packaging tool |
|---|---|---|---|
| AutoCAD | Xrefs, images, PDF/DWF underlays, fonts, plot styles | Full (absolute), relative or no path, per reference | eTransmit |
| Revit | Linked Revit models, CAD links, images | Relative or absolute ("Path Type" in Manage Links) | eTransmit for Revit |
| SolidWorks | Parts in an assembly, drawings of parts and assemblies | Path to each referenced document | Pack and Go |
Absolute paths (P:\Projects\2026\Tower\xref\grid.dwg) break as soon as the recipient's
drives are named differently. Relative paths (..\xref\grid.dwg) keep working wherever
the project folder lands — as long as the subfolders arrive exactly as you sent them.
That second condition is where many transfer methods fail. Email can't carry folders. Cloud drives keep the tree online but usually zip it on download, so the recipient must extract it to the right place. Some tools flatten folders into a list of files, which breaks relative paths outright.
How do I prepare a CAD project for sending?
AutoCAD: relative xrefs and eTransmit
- In the External References palette, check that each xref uses a relative path. An xref on a different drive from the host drawing can't be stored as relative — move it into the project folder first.
- Run eTransmit and choose a folder as the transmittal type, so the package is a plain folder rather than an archive.
- Read the transmittal report for missing files before you send anything.
Revit: links and eTransmit for Revit
- Open Manage Links and look at the Path Type column: links should be relative.
- Close the models and run eTransmit for Revit. It copies the host model and its dependent files and converts absolute paths into relative paths or no path, so the dependent files can be found in the package.
- For a workshared model, send a detached copy — the recipient should not work on a copy of your central model.
SolidWorks: Pack and Go
Pack and Go gathers the related files of a design — parts, assemblies, drawings and other references — and copies them into a folder or a ZIP file. Choose the folder option, and include drawings if the recipient needs them.
How do I send the CAD project folder?
Once the project is packaged as a folder, send it as a folder:
- Open StrongFolder and click Upload Folder.
- Pick the packaged project folder. Nothing is uploaded; the browser only reads the tree.
- Send the link to the consultant, contractor or client.
- They choose where to save it and get the same folder tree, then open the host file — relative references resolve on the first try.
Folders are sent as folders: subfolders and file names are kept, nothing is zipped. Saving a whole folder with its structure uses the File System Access API: Chrome, Edge, Opera and other Chromium browsers on a computer. Other browsers can download the files one by one or as a ZIP.
Free · in your browser · no sign-up
Which method should I use to send large CAD files?
| Method | Folder structure | Free size limit | Upload first? | Sender online? | Best for |
|---|---|---|---|---|---|
| No | ~20–25 MB | Yes | No | One small DWG or PDF | |
| Cloud drive (Google Drive, OneDrive, Dropbox) | Kept online, usually zipped on download | Your storage quota | Yes | No | Files that must stay available |
| CDE (Autodesk Docs, other project platforms) | Yes, managed | Plan-based | Yes | No | Ongoing multi-party collaboration |
| Transfer service (WeTransfer-type) | Usually zipped | Check the vendor's current plan | Yes | No | Occasional one-off sends |
| StrongFolder (P2P) | Kept, no ZIP | None set by the service | No | Yes | Fast handoff of a packaged project |
Big projects add up quickly: a federated BIM model with links and a laser-scan point cloud can reach tens or hundreds of gigabytes. Any internet transfer is limited by the sender's upload speed — 50 GB at 100 Mbit/s takes at least about 67 minutes (400 gigabits ÷ 100 Mbit/s), at 50 Mbit/s about 2.2 hours. A direct transfer avoids doing that wait twice (upload, then download).
When should I not use StrongFolder for CAD files?
- The team works on the same models every day. Use a common data environment or PDM/vault system with version control, permissions and an audit trail.
- A contract requires a formal transmittal record in a specific platform. Follow it.
- You can't keep your computer on until the recipient finishes. The sender's browser tab must stay open and online until the recipient finishes downloading — files come from the sender's device, not from a server.
- The recipient will open the link on a phone or tablet and needs the folder structure. Saving a whole folder needs a Chromium browser on a computer.
Is it secure enough for project files?
WebRTC encrypts every data channel with DTLS, so the file stream is encrypted in transit on every connection. Files are never uploaded to or stored on a StrongFolder server. To create the link, the service keeps transfer metadata: file and folder names, sizes and the number of files. If a direct connection is impossible (strict corporate firewall, some mobile networks), the encrypted stream passes through a StrongFolder relay (TURN) server. The relay forwards the data and does not store it. Anyone with the link can download while you share, so send it directly to the intended recipient and click Stop Sharing when they confirm receipt. See Security & privacy and secure file sharing.
Summary
To send CAD files without broken references, make paths relative, keep every reference in the project folder, package with eTransmit or Pack and Go into a folder, and send that folder as a folder. A direct peer-to-peer transfer does the last step without a ZIP or an upload; a common data environment remains the right home for day-to-day collaboration. For drawings and PDFs, see How to send large documents; for folders in general, How to send a folder without zipping it.