As-Built 3D Scanning: The Builder's Record of What's Inside the Walls

Every builder knows the call. A leak shows at the skirting eight months after handover. A tiler drills into a cold-water line. An owner wants to hang a 75-inch TV and asks where the cables run.

The answer was in plain sight for a short window of the build, between the pre-line inspection and the day the sheeters arrived. After that it lives in the memories of the trades who ran the services and on drawings that may or may not have been marked up.

As-built 3D scanning captures that answer before the walls close. This guide covers what the scan records, when to book it, how builders use it after handover, and how long the record stays live.

Why the drawing set isn't the as-built

Drawings show design intent. The frame shows what actually happened on site, and the two drift apart on every job.

• Services move. The plumber shifts a waste to clear a joist. The sparky reroutes around a nogging. A variation moves the vanity 300 mm.
• Mark-ups depend on memory. Whether a change reaches the drawings depends on who remembered, and when.
• Photos lose the context. Phone photos lack spatial scale and miss critical angles. A close-up of a junction box doesn't show which wall it's in or how high it sits.
• The cavity closes for good. In standard Australian construction, services run through 40–50 mm cavities between the timber frame and the external brickwork. Once plasterboard or brick wraps go on, that access is gone.

When something goes wrong later, the gap between the drawings and the frame is where the time and money disappear: exploratory cut-outs, patching, repainting and a frustrated owner.

Reality capture in construction: what the scan records

An as-built 3D scan is a walkable model of the frame, captured room by room before anything is covered. Our 3D laser scanning for construction runs on a Matterport Pro3: Class 1 eye-safe LiDAR at 100,000 points per second, paired with 134MP HDR panoramas, so it's safe around working trades and captures cleanly in direct sun.

One capture records:

• Every framing bay. Studs, noggings, plates and the fixing points you'll want for shelving, grab rails and wall-hung vanities.
• Every rough-in. Plumbing, electrical, data and A/C runs, in position and to scale.
• The cavity voids. With cavity void capture, included in the Tier 2 audit, the 40–50 mm space between frame and brickwork, where pipes and cables are hardest to find later.
• Slab penetrations and set-downs. Waste pipes, floor wastes and conduit stubs before flooring and cabinetry cover them.
• Wet areas. Shower mixers, drainage lines and noggings before waterproofing goes on.

Your interactive model is live within 24 hours of capture. Anyone with the link can walk it in a browser, with no software to install, and take reference measurements on screen.

What it isn't

The scan is an architectural-grade capture: a high-fidelity spatial reference for planning and coordination. Critical set-out is still confirmed on site, and boundary or level surveys stay with a registered surveyor. It records what was installed; it doesn't replace your certifier's inspections or your own QA.

When to book: after the pre-line inspection, before the sheeters

The capture window opens once the pre-line inspection is passed and closes when sheeting starts. That's when framing, rough-ins, slab penetrations and cavity voids are all exposed at once.

Book the audit the moment the pre-line inspection passes. We dispatch within 24–48 hours across South East Queensland and daily, on demand, on the Sunshine Coast, so a booking made at pre-line usually lands well ahead of the plasterboard delivery. Our pre-plaster inspection checklist covers what to check in the same window.

Pick the audit tier for the build

Every pre-gyprock audit includes 6 months of live tour hosting, which covers most build schedules.

• Tier 1 · Apartment or small home. Compact footprints of 150 m² or less. Book a Tier 1 audit
• Tier 2 · Standard home. Up to 4 bedrooms plus study and living, with the cavity voids captured. Book a Tier 2 audit
• Tier 3 · Executive residence. 5 to 6 bedrooms over multi-level structural layouts, with every level captured. Book a Tier 3 audit
• Tier 4 · Acreage and architectural. Split-level and complex structural builds, scoped by quote. Book a scoping call

Each link opens the dispatch console with that tier already selected. Every audit is scoped on request; see the full pre-plaster audit protocols for what each tier covers.

Where builders use the record after handover

A Queensland builder's exposure doesn't end at handover. The QBCC can direct a contractor to fix non-structural defects within 12 months of practical completion and structural defects for up to six years and six months (HIA). The as-built record works hardest across that tail.

Warranty callbacks

A leak shows behind a finished wall. Instead of opening plasterboard in three places, the trade opens the model, finds the run and cuts once. If a pipe is punctured years later, it's found in the model rather than through exploratory demolition.

Defect and variation disputes

When an owner and a trade disagree about what went in and where, the scan is a shared visual reference of what was installed, in position, on the capture date. It moves the conversation from memory to evidence.

Trade briefings without a site visit

Snapshot a wall bay, measure the pipe centres on screen and send it to the trade before they quote. They arrive with the right parts and a clear idea of where to cut.

The owner's next renovation

A handover pack that includes the frame record tells the owner where to fix a TV bracket, where the noggings sit and which wall carries the plumbing. It's a genuine point of difference in a builder's handover.

Protecting the neighbours as well

If the job involves demolition, excavation or piling beside occupied homes, the same technology records the neighbouring properties before work starts. See our guide to pre-construction condition surveys.

Design teams working on the existing building can take the capture further, into registered point clouds and Revit models, through our Scan-to-BIM services.

How long the record stays live

A defect can surface years after handover, so plan custody at booking, not when the callback comes in.

• 6 months live, included. Every pre-gyprock audit includes 6 months of live tour hosting, enough to cover most build schedules.
• Then archived, never deleted. When included hosting ends, the public link pauses and the capture moves to our internal vault.
• Reactivated on request. When a callback needs it, we bring the archived tour back online for another 3 months. Reactivate an archived tour
• Transferred, if you'd rather hold it. We can move the model into your own Matterport account. Transfers need a paid Matterport plan, because free accounts can't hold or display tours.
• MatterPak™ add-on for offline files. An optional paid add-on gives you the .OBJ mesh, .XYZ point cloud and reflected ceiling plan imagery to keep offline for CAD or Blender. It's a set of files, not an offline tour, and hosting fees still apply if you hold one. Add a MatterPak™

For builders carrying a six-and-a-half-year structural tail, the simplest setup is a MatterPak™ in the project file and the archived tour reactivated whenever a callback needs the walkthrough.

As-built 3D scanning FAQs

Lock in the capture before the walls close

The window is short and it only opens once per build. Send us the site address, the stage of the build and your sheeting date, and we'll confirm scope, access and a capture window. Every audit is scoped on request.

rchive is owner-operated from the Sunshine Coast: the person who scopes your job is the person on site, inducted, with White Card, SWMS and $20M public liability cover.

Book a Scan, or call 0437 596 350.

General information only. Defect timeframes and warranty rules change; check current QBCC requirements for your contract.