Rapid As-Built

TL;DR: A rapid as-built survey captures the actual three-dimensional condition of plant and equipment during a shutdown in hours rather than days, using high-speed laser scanning tied to a pre-established control network. It exists to keep measurement off the critical path: when an outage costs $50,000-$200,000 per hour, the as-built record cannot be the activity that holds up removal, fit-up, or recommissioning. This guide explains what rapid as-built involves, the methods and equipment, the accuracy you can expect, deliverables, cost drivers, and how ISS delivers it.

Key takeaways

• A rapid as-built survey captures comprehensive 3D plant condition in 15-45 minutes per scan setup, replacing the days of point-by-point total station work that traditional as-built documentation demands during a shutdown window.
• ISS achieves registered point-cloud accuracy of 2-6 mm across a typical processing-plant area using a Leica RTC360 or FARO Focus Premium, with control tied to a network established before the outage begins.
• The defining constraint is time, not technique: every scan, target and registration step is planned against the shutdown schedule so survey work runs parallel to mechanical activity and never becomes a critical-path item.
• Primary users are mining processing plants, alumina refineries, cement works, power stations and steel mills replacing or modifying equipment during planned turnarounds, where as-laid geometry must be locked in before reassembly.
• Cost is driven by area and complexity, attendance pattern (scheduled versus standby), turnaround speed for deliverables, and the level of modelling required — from a raw registered cloud through to a Revit or 12d as-built model.

What is rapid as-built

A rapid as-built survey is the fast capture and documentation of the actual position, dimensions and configuration of installed plant, structures and services — performed inside the compressed timeframe of a maintenance shutdown, turnaround or outage. It records what is physically there after work is done (or as it is found before work begins), as distinct from what the original design drawings or P&IDs claim should be there.

The "rapid" qualifier is not marketing. A conventional as-built survey of a congested process area using a total station might capture a few hundred discrete points over two or three days. A rapid as-built survey using terrestrial laser scanning captures tens of millions of points across the same area in a few hours, including geometry no one thought to measure — the pipe that was rerouted around a structural brace, the nozzle that ended up 40 mm off the isometric, the platform that encroaches on the removal path for a new gearbox.

The problem it solves is specific to shutdowns. During an outage, equipment is opened, isolated and accessible for the only window of the year. The plant owner needs three things from measurement, fast: confirmation that incoming components will fit the as-found space (fit-up), an accurate record of what was changed (as-built), and assurance that nothing on the critical path is waiting on a surveyor. Slow measurement defeats all three.

Key point: Rapid as-built is a discipline of sequencing as much as a measurement technique. The scanner is fast; what makes the survey "rapid" is that the control network, scan plan, target layout and registration workflow are all resolved before the shutdown starts, so the field crew arrives and captures rather than arrives and plans.

Why rapid as-built matters during a shutdown

The financial logic is the same that governs the whole shutdown. A mid-sized processing plant loses $50,000-$200,000 for every hour the outage runs over schedule (industry maintenance data). If the as-built or fit-check survey is on the critical path and takes a day longer than planned, the cost of that delay dwarfs the entire survey fee several times over.

There is a second, slower cost. When equipment is replaced or modified without an accurate as-built record, the next project inherits the uncertainty. Brownfield design teams modelling a tie-in from out-of-date drawings routinely discover in the field that the as-found geometry differs from design by 50-500 mm. A clash found on site during the next shutdown costs 10-20 times what it costs to find in the design office from an accurate point cloud. Capturing a comprehensive as-built during this shutdown is the cheapest insurance against rework in the next one.

Rapid as-built becomes critical when any of the following are true: large rotating equipment (mills, kilns, fans, gearboxes) is being removed and replaced; new plant is being tied into existing structures or pipework; a removal or lift path must be verified for clearance before the lift; or the asset register and engineering drawings are known to be unreliable and the shutdown is the only access window to correct them.

The rapid as-built process

ISS runs rapid as-built work as a five-phase sequence built around the shutdown schedule. The field capture is the shortest phase by design — the planning ahead of it is what keeps survey off the critical path.

Step 1: Pre-shutdown scope lock and scan planning

Four to six weeks out, ISS reviews the shutdown work list, equipment drawings and P&IDs to identify exactly what must be captured and to what tolerance. A scan plan is produced: setup positions, expected occlusions, target locations, and the registration strategy. This is also where the deliverable is defined — raw cloud, 2D as-built, or full 3D model — because that decision drives field density and time.

Step 2: Control network establishment

Before the outage starts, a stable control network is established around the work area using a Leica TS16 or MS60 total station, with permanent or semi-permanent reference targets placed on surrounding structures. Tying every scan to this network means the as-built data is georeferenced to the plant coordinate system and the registration is checked against survey-grade control rather than cloud-to-cloud alignment alone.

Step 3: Rapid field capture

During the outage, the crew scans the work area as it becomes accessible. A Leica RTC360 captures roughly two million points per second and completes a full-dome scan with HDR imagery in under two minutes; allowing for movement and target acquisition, each setup runs 15-45 minutes. A congested process area is typically covered in 8-20 setups over a few hours, with the crew working around — never holding up — the mechanical trades.

Step 4: Registration and verification

Registered in the field on a tablet using Leica Cyclone FIELD 360, then refined in Cyclone REGISTER, the scans are bundled into a single coordinated point cloud. Registration error and control residuals are checked against tolerance immediately, so any gap or weak setup is re-scanned while the area is still open rather than discovered after recommissioning.

Step 5: Deliverable production and reporting

The registered cloud is delivered first — often within 24-48 hours — so engineering can begin fit-up and clash work straight away. Modelled deliverables (2D as-built drawings, Revit or 12d models, deviation reports comparing as-built to design) follow on the agreed turnaround, typically 5-10 business days depending on scope.

Methods and equipment

Rapid as-built is dominated by terrestrial laser scanning because it is the only practical way to capture comprehensive geometry inside a shutdown window. ISS pairs the scanner with total-station control and, where appropriate, handheld or UAV capture for areas a tripod cannot reach.

Leica RTC360 laser scanner

The primary rapid as-built instrument. It captures up to two million points per second to a range of 130 m, with a single full scan plus imagery in under two minutes. Its on-board Visual Inertial System pre-registers scans as the crew moves between setups, which is what makes high-setup-count areas viable inside a tight schedule. 3D point accuracy is in the 2-6 mm range at typical plant distances.

FARO Focus Premium

Used where longer range or a lighter footprint suits the access. The Focus Premium ranges to 350 m and operates across the temperatures and dust loads typical of a live processing site, with ranging noise around 1 mm at close range.

Leica MS60 MultiStation / TS16 total station

Provides the survey-grade control the scan network is registered to, and captures discrete high-accuracy points (flange faces, nozzle centres, anchor bolts) where a few millimetres matters more than overall coverage. Reflectorless measurement reaches points that cannot be safely targeted.

Software

Leica Cyclone FIELD 360 for in-field registration and verification, Cyclone REGISTER for office-grade bundle adjustment, and CloudCompare for deviation analysis. Modelled deliverables are produced in AutoCAD, Revit (scan-to-BIM) or 12d Model as the client requires.

Key point: Range and speed specifications matter less than registration discipline. A point cloud registered cloud-to-cloud without survey control can look perfect on screen and still drift several centimetres across a long process building. Tying the scans to a pre-established control network is what makes a rapid as-built trustworthy for fit-up and tie-in design.

Accuracy and standards

Rapid as-built accuracy is governed by the scanner's ranging precision, the quality of registration, and the strength of the control network it is tied to. The table below summarises what ISS delivers and the typical industry benchmark.

Relevant Australian Standards include AS 5488 for the classification and recording of subsurface utility information where services are captured, and the construction tolerance standards the as-built is checked against — AS 4100 for steel structures and AS 3600 for concrete. Crane and rail geometry captured during a shutdown is assessed against AS 1418. All ISS measurement is made with equipment calibrated to ISO 17025, and survey reports carry a stated accuracy and the coordinate system used so the data is defensible for engineering and audit.

When you need it

Rapid as-built is the right service whenever measurement must keep pace with a maintenance event rather than the other way around.

Mining and mineral processing

SAG and ball mill relines, kiln shell replacements, crusher rebuilds and conveyor modifications all expose geometry that must be recorded before reassembly. Rapid scanning captures the as-found and as-left condition without adding hours to the reline window.

Alumina, cement and steel

Calciner and kiln work, cooler re-supports, and furnace tie-ins are classic rapid as-built jobs: high downtime cost, congested access, and a hard recommissioning date. Comprehensive capture during the outage also feeds the next campaign's design.

Power generation

Boiler, turbine hall and precipitator outages need clearance verification for removals and an accurate record of any modification, captured between isolation and re-energising.

Brownfield tie-ins and capital projects

Where new plant connects to existing infrastructure, a rapid as-built scan of the connection zone during the shutdown gives the design team accurate existing conditions and removes the guesswork that causes field rework.

⚠️ Watch out: A rapid as-built captures what is visible at the time of scanning. Geometry that is still lagged, boxed-up, or buried will not be in the cloud. The single biggest cause of an incomplete as-built is scanning before insulation or cladding is removed — sequence the scan to the moment of maximum exposure, not the moment that is convenient.

Deliverables

What you receive is agreed during scope lock and tuned to how fast engineering needs it. A typical rapid as-built package includes:

The staged delivery is deliberate: the registered cloud and a hosted viewer go out first so fit-up, clash detection and tie-in work can start during the outage, and the modelled products follow once the shutdown pressure has eased.

Cost factors

Rapid as-built is quoted per project after a short scoping call. Pricing reflects the survey itself plus the shutdown premium — standby availability, safety certifications, and after-hours work all carry a loading. The main drivers:

ROI context: A comprehensive rapid as-built of a major work area typically costs $10,000-$30,000. A single day of avoidable shutdown extension at a mid-sized plant costs $1.2 million or more. When the survey keeps measurement off the critical path and prevents one fit-up problem from becoming a schedule problem, the payback is measured in hours, not months.

How ISS delivers it

ISS treats rapid as-built as a shutdown discipline first and a scanning job second. We lock scope four to six weeks out, walk the site before the outage, and establish control while the plant is still running so the field crew can capture from hour one. Our surveyors hold current confined space, working-at-heights and site-specific certifications for live and isolated industrial environments, and we plan attendance — scheduled or standby — around the mechanical schedule so survey runs parallel to the trades.

We register and verify in the field, so weak setups are caught and re-scanned while the area is open, and we deliver the registered cloud within 24-48 hours so engineering is never waiting on us. As an independent firm we are not tied to any OEM or EPC, and we work to your coordinate system, your tolerances and your deliverable formats. The result is an as-built that is fast enough for the shutdown and accurate enough for the next project.

Frequently asked questions

How fast is a rapid as-built survey?

Field capture of a congested process area typically takes a few hours — 8-20 scan setups at 15-45 minutes each. The registered point cloud is usually delivered within 24-48 hours, with modelled deliverables following over 5-15 business days depending on scope. The whole point of the service is that capture and first delivery happen inside the shutdown window.

How accurate is a rapid as-built compared with a slower survey?

For comprehensive geometry, a control-tied laser scan is as accurate as it needs to be: 2-6 mm point accuracy and sub-4 mm registration. Where a specific feature needs tighter accuracy — a flange face, a nozzle centre, an anchor-bolt pattern — ISS captures those discrete points with a total station to ±1-3 mm. You do not trade accuracy for speed; you match the method to the tolerance.

Will the survey slow down the shutdown?

No, if it is planned properly. Control is established before the outage, the scan plan is fixed in advance, and the crew scans each area as the trades release it. Survey work runs parallel to mechanical activity and should never sit on the critical path. Delays come from unplanned survey, not from survey itself.

Can you scan while the area is still hot or partly live?

Yes, with the appropriate isolations, permits and PPE. Laser scanning is non-contact and works from a safe standoff, which is one of its advantages in a shutdown — it captures hazardous or hard-to-reach geometry without putting a person at the measurement point. We coordinate scan timing with the permit-to-work system.

What do we actually receive, and when?

You receive a registered point cloud and a hosted panoramic viewer first — often within 24-48 hours — so engineering can start fit-up and clash work immediately. 2D as-built drawings, scan-to-BIM models and deviation reports follow on the agreed turnaround. Every package includes a survey report stating method, accuracy and coordinate system.

Rapid as-built only works when it is planned before the shutdown, not booked during it. If you have an outage, turnaround or capital tie-in coming up, the time to scope the survey is now — while control can be established and the scan plan resolved against your work list. Call ISS on 0407 057 015 or visit industrialspatial.com to request a fixed-price quote and keep measurement off your critical path.

Related reading:

• Shutdown survey services: planning, safety and execution
• As-built surveying explained
• 3D laser scanning for industrial plants