File Sharing for Architects: CAD and BIM Files

Architecture firms sharing Revit .rvt, AutoCAD .dwg, and IFC BIM models need tools built for reference-heavy, version-sensitive workflows — not generic file transfer. The strongest stack: Autodesk Construction Cloud or BIM 360 for live model collaboration, Newforma or Procore for project correspondence, and a secure transfer service like HexaTransfer or Tresorit Send for RFPs, permit submittals, and final deliverables. A federated BIM model on a major commercial project runs 2 to 8 GB. The coordination drawings, spec books, and submittal packages around it can easily hit 50 GB per project.

Why Architectural Files Break Standard Transfer Tools

Revit files carry embedded references to linked models (MEP, structural, landscape), external shared parameters, and custom families stored locally. Strip the ecosystem and the file opens broken. AutoCAD .dwg files reference xrefs by relative or absolute paths. Miss one xref and the drawing shows missing-sheet placeholders.

The consequences on a busy project:

• A 1.2 GB Revit architectural model links to a 2.3 GB MEP model, a 1.8 GB structural model, and 200 MB of Enscape assets
• Emailing just the .rvt to a consultant produces errors the moment they open it
• Sending the whole package requires either Autodesk eTransmit, a manual folder archive, or a shared cloud workspace

Most generic transfer services handle the bytes fine. The challenge is preserving the link structure so the recipient's Revit session actually works.

The Autodesk eTransmit Workflow

For one-off shares to external consultants who don't have access to your cloud workspace, eTransmit (built into Revit) packages the host model plus all linked models, CAD links, images, and external shared parameters into a single folder or ZIP.

Steps:

1. File > Save As > eTransmit for Revit
2. Select the linked files to include
3. Choose output folder or ZIP
4. Transfer the archive via your preferred tool

For AutoCAD, the equivalent is the eTransmit command, which bundles the .dwg plus xrefs, fonts (.shx), plot style tables (.ctb), and image underlays into a package. Both tools preserve relative paths so the recipient can open the file without re-linking.

BIM 360 and Autodesk Construction Cloud

For ongoing collaboration rather than one-off sends, cloud-based CDE (Common Data Environment) platforms have become the industry default:

• Autodesk Construction Cloud (ACC): $70/user/month for Docs, higher for full suite
• BIM 360 (legacy, being sunset into ACC): similar pricing
• Bentley ProjectWise: enterprise pricing, strong on infrastructure projects
• Trimble Connect: $10 to $30/user/month, multi-platform
• Procore: project management focus, $375 to $1,500+/month per project

ACC Docs handles file versioning, markup, and transmittal workflows inside one environment. Subcontractors and consultants get access to exactly the documents relevant to their scope, with approval workflows that map to AIA document phases (schematic design, design development, construction documents, CA).

RFP and Permit Submittal Packages

Proposal responses and permit applications travel outside the CDE. A typical RFP response runs 40 to 200 MB: firm qualifications, project approach, team resumes, cost narrative, and reference projects. Permit submittals are heavier: full CD sets (.pdf, often 500 to 1,500 pages at 150 to 500 MB), calculation reports, specs book, energy compliance forms.

Municipal e-permit portals (ePlans, ProjectDox, Accela) handle most jurisdictions now. But agency communication around deficiencies and resubmittals often happens by email, where 25 MB attachment caps force workarounds. A password-protected transfer with a 30-day expiration solves that cleanly — and the audit trail of "link sent on date X, opened on date Y" strengthens your record if scheduling disputes arise later.

Protecting Proprietary Details and Design IP

Your detail library is firm IP. A curtain-wall detail your senior technical architect spent 200 hours refining shouldn't leak to a competing firm via a contractor's Dropbox share.

Practical controls:

• Watermark issued drawings with project number and phase (schematic, design development, construction documents)
• Export flattened PDFs for external review, not native .dwg or .rvt
• For CA-phase issuances, use tamper-evident e-signature on every sheet
• For detail libraries, store masters on firm servers, never on individual laptops or personal clouds
• Track contractor access via your CDE's audit log

For highly sensitive projects — government facilities, data centers, high-net-worth residential — add NDA clauses that specify the file-sharing channel and prohibit forwarding. Back the NDA with an actual DLP policy that blocks forwarding to unauthorized domains.

IFC and Cross-Platform Interoperability

Not everyone uses Revit. Your MEP engineer might work in Tekla, your structural consultant in Bentley, your landscape architect in Vectorworks. IFC (Industry Foundation Classes) is the open exchange format — IFC4 is the current major version, IFC4.3 adds infrastructure types.

Export IFC when sharing:

• With consultants on different BIM platforms
• For clash detection in Navisworks or Solibri
• For permit authorities that accept or require IFC submissions (common in the Nordics and increasingly in the EU)

IFC files preserve geometry and classification but lose some authoring-tool-specific parameters. For rich coordination, pair IFC with the native file in the same transfer package. Recipients who have the native tool get full fidelity; everyone else gets working geometry.

Contractor and Subcontractor Handoffs

During construction, drawings change constantly. Each addendum, RFI response, and ASI needs tracked distribution. Most firms run two parallel channels:

1. Formal transmittal through the CDE: logged, versioned, tied to specific discipline and spec section
2. Informal coordination: email attachments, chat message screenshots, the field engineer's phone

Formal wins for legal defensibility. Informal wins for speed when a framer on site needs a clarification before lunch. Good project management explicitly reconciles the two: every informal exchange gets logged as a formal RFI by end of day.

For subcontractor-to-subcontractor coordination that doesn't involve the GC, a shared transfer link works. Sub A sends the latest coordinated duct routing to Sub B as a .pdf and .dwg, password-protected, expiring in 72 hours. Lightweight, auditable, no new platform required.

Data Management After Project Closeout

Closeout generates the final document archive: record drawings, O&M manuals, warranty documents, commissioning reports, and the as-built BIM. Typical closeout archives run 20 to 100 GB.

Deliver the archive on external media (encrypted USB or BitLocker-protected drive) for physical handoff, and also upload to an archival cloud location with a 10-year retention policy. AIA Document B102 and state professional-services contracts often specify retention periods — commonly 7 to 10 years after substantial completion.

For your own firm archive, reference the project code on every folder. Five years later when you're asked to stamp a tenant improvement permit based on the original shell drawings, you want to find that CAD file in under a minute.

A Practical Transfer Policy for a Mid-Size Firm

• Inside the firm: Autodesk Construction Cloud for active projects
• With consultants: same CDE plus monthly IFC snapshots
• RFPs and proposals: password-protected transfer, 30-day expiration
• Permit submittals: municipal e-plans portal plus backup PDF transfer
• Client presentations: PDF exports through encrypted transfer or Newforma
• Closeout archive: encrypted drive plus 10-year cloud retention

Try it at hexatransfer.com — free, no account, 10 GB max.