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File Transfer

Send Construction Blueprints: Share CAD Files Online

Send large construction blueprints and CAD files online. Share DWG, DXF, and PDF plans with contractors and architects securely and quickly.

Construction blueprint delivery means sending multi-megabyte DWG files, reference XREFs, embedded images, and print-ready PDF plotsets to contractors, engineers, inspectors, and owners — without any of them being compressed, flattened, or stripped of external references. A browser-based transfer service handles it in one upload: zip the drawing set with its XREFs, upload, share the link. 300 MB, 3 GB, or a 15 GB full Revit model, the workflow is the same. Email fails at 25 MB. FTP servers require IT setup on both sides. BIM 360 / Autodesk Construction Cloud requires licensed seats for every recipient. Transfer links require nothing on the recipient's side except a browser.

The file formats on a typical project

| Format | Use | Typical size | | --- | --- | --- | | .dwg | AutoCAD native, 2D drawings | 2–80 MB per sheet, 200 MB for a sheet set | | .dxf | CAD interchange format | Similar to .dwg | | .rvt | Revit model (BIM) | 100 MB – 5 GB | | .ifc | IFC (Industry Foundation Classes, buildingSMART) | 50 MB – 2 GB | | .pln | ArchiCAD project | 200 MB – 3 GB | | .3dm | Rhino model | 50 MB – 1 GB | | .skp | SketchUp model | 20 MB – 500 MB | | .pdf plotset | Printable construction documents | 20 MB – 500 MB | | .nwd / .nwc | Navisworks published/cache | 500 MB – 10 GB | | Point cloud .rcs / .e57 | Laser scan survey | 2–50 GB |

A full DD (Design Development) issuance on a mid-size commercial project is routinely 800 MB to 2 GB once XREFs, linked images, and the full sheet set are bundled.

The XREF problem nobody warns new users about

AutoCAD drawings reference other drawings via XREFs. A floor plan references the site plan, the structural grid, and the title block. Send just the floor plan .dwg and the recipient opens it with "Unresolved XREF" messages — the drawing appears empty or missing critical layers.

The fix before upload: run eTransmit in AutoCAD (or the ArchiCAD equivalent). eTransmit packages the drawing and all its XREFs, fonts, image attachments, and plot configurations into a single zip. For Revit, use Collaborate → Manage Links to understand dependencies and File → eTransmit (Autodesk's add-in) to package the model with linked files.

Project_CD_Issuance_2026-04-01.zip
├── Sheets/
│   ├── A-101 Floor Plan.dwg
│   ├── A-201 Elevations.dwg
│   └── ...
├── XRefs/
│   ├── site_plan.dwg
│   ├── title_block.dwg
│   └── structural_grid.dwg
├── Images/
│   └── logo.png
├── Fonts/
│   └── romans.shx
├── PlotConfigs/
│   └── ANSI_D.pc3
└── README_transmittal.txt

Why sending PDFs alone isn't enough

A PDF plotset is great for printing and markup (Bluebeam Revu, Adobe Acrobat), but it's flat. Contractors' estimators use the DWGs to pull quantities: counting doors, extracting wall lengths, measuring rooms. Shop drawings come back as DWGs. BIM coordination requires .rvt or .ifc. Deliver both: the native CAD/BIM and a PDF issuance set for review.

Size tiers and transfer expectations

| Project type | Typical issuance size | | --- | --- | | Tenant improvement | 50–300 MB | | Single-family residential full CDs | 200–800 MB | | Small commercial (10,000 sq ft) | 500 MB – 2 GB | | Large commercial / multifamily | 2–10 GB | | Hospital, laboratory, data center | 5–30 GB | | Infrastructure (bridge, highway) | 10–50 GB | | As-built with point cloud | 20–200 GB |

For anything under 10 GB, a single browser upload is the cleanest delivery. Above that, a project-specific cloud location (BIM 360, Procore, Aconex) with a mirrored transfer link for external reviewers works.

Issuance discipline and naming conventions

CAD-delivery naming follows the National CAD Standard (US), ISO 19650 (international), or AIA E-203 BIM protocol. A zip delivered to a contractor's estimator should include:

  • Transmittal PDF listing every file, revision number, and issue date
  • Sheet index
  • LATEST folder at the top level — pointing to the current revision
  • A Revision_History.txt noting what changed from the previous issuance

ISO 19650 file naming: Project-Originator-Volume-Level-Type-Role-Number.ext — e.g., BigCo-ArchFirm-Z1-L01-DR-A-1001.dwg. Consistent naming across issuances avoids the "which one's the latest?" email chain.

Who receives what

  • General contractor: full DWG/RVT set + PDF plotset + specs .pdf (often a 200–500 page Division 0–48 document)
  • Structural engineer: structural DWGs, loads diagrams, rebar schedules
  • MEP sub: plumbing/electrical/HVAC DWGs, one-line diagrams, fixture schedules
  • Building department (permit submission): stamped PDF plotset, sometimes DWG on request
  • Owner: PDF only, sometimes 3D model walkthroughs (.nwd)
  • Lender: PDF executive summary, specifications

Tailor the delivery to the audience. A lender doesn't need the structural XREFs; a sub does.

Encryption for sensitive projects

Government buildings, data centers, embassies, defense contractors — projects where blueprints aren't public record — benefit from end-to-end encryption on transfer. AES-256-GCM keyed from a PBKDF2-derived 256-bit key, negotiated in-browser using the Web Crypto API, keeps the drawings unreadable to the transfer service. Even under subpoena, the service can produce ciphertext only.

HexaTransfer runs this pipeline. The architect uploads in Chrome; the drawings are encrypted in the tab before the first byte goes up. The contractor downloads with the shared password, decrypts in the browser, opens the DWGs in AutoCAD.

Download confirmation on the construction schedule

Missed issuance dates cascade through a project schedule. A download notification — "contractor A downloaded CD issuance at 14:32 on 15 April" — gives the project manager a paper trail without phone tag. If the expiry is 30 days, the PM has an enforcement mechanism: "the link expires Friday; pull the set before then or we cut a new one at our cost."

Revision control on transfer links

Never reuse the same link for a new revision. Each issuance gets its own link, its own filename (_Rev_B, _Rev_C), and its own expiry. The previous link stays live until its expiry or is explicitly revoked. This avoids the "I downloaded the old version" defence when a contractor builds to superseded drawings.

Mobile review on the jobsite

Superintendents and inspectors increasingly mark up drawings on iPads with Bluebeam Revu iPad app, PlanGrid (now Autodesk Build), or Procore. A browser-based transfer link opens on iPadOS 13+ without installing anything; the zip downloads, the user opens the PDFs in Files, and Bluebeam iPad ingests them. Same flow on Android tablets.

Transfer service comparison for construction

| Service | Max size (free) | Preserves folder structure | E2E encryption | Audit log | | --- | --- | --- | --- | --- | | WeTransfer Free | 2 GB | Yes (via zip) | No | Basic | | SwissTransfer | 50 GB | Yes | Password-protect at rest | Basic | | BIM 360 / ACC | Quota-based | Yes (models/sheets) | No (at-rest only) | Yes | | Procore Files | Quota-based | Yes | No | Yes | | Dropbox Transfer | 100 GB (paid) | Yes | No | Yes | | HexaTransfer | 10 GB | Yes (via zip) | Yes (AES-256-GCM in-browser) | Yes |

Drawings are the contract. The delivery mechanism has to respect that.

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

Send large files securely with end-to-end encryption

Transfer files up to 10 GB for free with end-to-end encryption. No account required. Your files are encrypted in your browser before upload — no one else can read them.

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