TL;DR
Ask for E57 as the neutral master archive, RCP/RCS if your team works in Autodesk tools, and LAS when civil or survey consultants consume the data. A typical 100,000 sq ft interior produces 25–60 GB of E57 and 15–30 GB of RCP.
Point Cloud File Formats Explained: E57, RCP, LAS, and PTS
A point cloud is only useful in a format your software opens without a conversion step. Format is the last line of a deliverable spec and the first thing that goes wrong: a design team receives 40 GB of a format their machines can't index, and the dataset sits unused while somebody hunts for a converter.
Four formats cover nearly all AEC and survey work. Here is what each one is for.
E57 — the neutral master
ASTM E2807 defines E57 as a vendor-neutral exchange format. It stores structured scan positions, XYZ coordinates, intensity, RGB color, and per-scan metadata in one file or a file set, and every major registration and modeling package imports it.
Ask for E57 when: you want an archive copy that will still open in ten years, when multiple consultants on different software stacks need the same data, or when the scan record has legal or preservation value. E57 is the format to keep after the project closes.
Cost: the largest of the four in practice. A 100,000 sq ft interior typically lands at 25–60 GB of E57 depending on point spacing and whether color is included.
RCP and RCS — the Autodesk pair
RCP is an Autodesk ReCap project file; the RCS files it points at hold the indexed points. The pairing matters: RCP alone is a manifest, so a delivery that ships the RCP without its RCS folder is an empty project.
Because the data is spatially indexed, Revit, Civil 3D, and AutoCAD stream only the points in view. That is why a 30 GB RCP navigates smoothly in Revit while a same-size raw file will not.
Ask for RCP/RCS when: anyone on the project models in Revit or drafts in AutoCAD. For Scan to BIM work this is the working copy the modelers actually attach.
Cost: the same 100,000 sq ft interior comes in around 15–30 GB of RCP/RCS — smaller than the E57 because indexing discards redundancy.
LAS and LAZ — the survey and civil standard
LAS is the ASPRS lidar standard, built for aerial and terrestrial survey data. Its advantage is classification: points carry a class code (ground, vegetation, building, and so on), which is exactly what a civil engineer needs to pull a surface from a site scan. LAZ is losslessly compressed LAS, often a fraction of the original size, and every civil package reads it.
Ask for LAS/LAZ when: a survey or civil consultant is downstream, when the deliverable feeds a topographic surface or earthwork calculation, or when a site scan needs to sit in state plane coordinates alongside other survey data.
PTS — the plain-text fallback
PTS is an ASCII list: one line per point, XYZ plus intensity and color. No structure, no index, no metadata. It reads everywhere and it is the largest and slowest option, because text costs several times what binary does for the same point.
Ask for PTS when: a specialist tool in the chain accepts nothing else. Otherwise, don't.
Choosing without a meeting
| If the consumer is… | Ask for |
|---|---|
| Revit, AutoCAD, Civil 3D | RCP + RCS |
| Mixed software, or long-term archive | E57 |
| Survey, civil, earthwork | LAS or LAZ |
| A legacy or niche tool | PTS |
| Non-technical reviewers | A hosted viewer link, not a file |
The last row deserves emphasis. Owners and reviewers who want to look at a building rarely want a multi-gigabyte download; point cloud hosting puts the same dataset behind a browser link with measurement tools, which usually ends the file-format conversation for that audience.
Practical delivery notes
- Name the coordinate system in the spec. A correctly formatted file in the wrong coordinate system still fails coordination. Say the projection and vertical datum, or say "project coordinates" explicitly.
- Ask for both a master and a working copy. E57 archived, RCP delivered — the marginal cost of exporting a second format at delivery time is far lower than converting later.
- Confirm accuracy separately from format. Format has no bearing on it. Registered mobile capture holds ±5mm under survey control, and that number belongs in the deliverable spec next to the format. See what ±5mm accuracy means for how that figure is verified.
- Plan transfer, not just export. Datasets in the tens of gigabytes move by shared drive or drive shipment; email and consumer file links are not a delivery method.
- Organize before you distribute. A single monolithic cloud is harder to work with than a split by level or building. Organizing point cloud data for Scan to BIM covers the split conventions modelers expect.
The one-sentence version
Archive E57, work in RCP, hand LAS to the civil team, and treat PTS as a compatibility patch — then write whichever you chose into the deliverable spec alongside the coordinate system and the accuracy requirement.
Related: point cloud vs. BIM model covers whether a file is even the right deliverable, and point cloud services lists what registration and classification include.