Structural layout · measured record
Scanner → point cloudWhen a Periodic Structural Inspection notice arrives, the owner must provide as-built structural layout plans, and many buildings have none. We produce the measured documentation the professional engineer works from, including the geometry for reconstructing missing plans.
Structural layout · measured recordScanner → point cloudThe Building Control Act permits the Commissioner to require a structural inspection after the 5th year (non-residential) or 10th year (residential) from the last TOP, or CSC where no TOP was granted. The regime is notice-triggered: BCA serves a Notice of Inspection, and the owner’s duties then include appointing a professional engineer promptly, providing access, and providing a set of as-built structural layout plans plus the building’s maintenance and A&A history. Owners without plans face a real problem, and BCA’s own guidance for a second-stage investigation includes reconstructing the structural plans if they are not available.
The practical trigger for calling us is narrow and common: the notice is in hand, the PE has been appointed or is being appointed, and nobody can produce structural layout plans that match the building. That is a measurement problem, and it is solvable inside the compliance window if it starts early.
Where the plans exist at BCA, buy them first: see the plan purchase guide; when they cannot be obtained, measurement is the remaining route. Doing it in that order matters, because purchased plans are cheaper than a survey and because the PE may need to compare what was approved against what exists. If the purchased set turns out to be partial or illegible, the survey scope becomes narrower and cheaper: fill the gaps rather than start again.
Two other early moves save time: give the PE the maintenance and A&A history in whatever state it exists, and identify which parts of the building have been altered. Alterations are where the approved record and the physical building diverge, so they usually drive the survey scope.
Handheld SLAM covers occupied floors, plant rooms, staircases and basements in a walk-through without closing anything. Tripod stations go in where a specific element will be dimensioned tightly. Where structure is behind finishes, we capture the finished surface and record it as such: the PE decides where opening up is warranted, and we can return to capture opened areas.
Sequencing follows the building’s operations, after-hours capture for retail and F&B, floor-by-floor coordination in tenanted offices, escorted access for plant and service risers. We work to whatever access regime the managing agent can actually deliver, because a survey plan that assumes unrestricted access will not survive contact with a live building.
A laser measures visible surfaces. Reinforcement, embedded steel, post-tensioning, concrete cover, internal condition and material strength are outside its reach: those questions belong to the PE’s investigation methods, which may include opening up, non-destructive testing or coring. We record geometry: member sizes as finished, spans, levels, alignment, deflection where it is geometrically visible, and the location of visible interventions.
We also record what we could not reach. A coverage note listing inaccessible rooms, sealed voids and obscured soffits is part of the deliverable, because the PE needs to know where the record stops.
The structural inspection is performed by a professional engineer registered in the civil or structural discipline with no professional or financial interest in the building. A survey deliverable is not “record structural plans”, those are a defined construction-stage submission, and it is not a structural assessment. Volumet supplies measured geometry; the engineering judgement, the report and the statutory role remain the PE’s.
Intervals, owner duties, deadlines and penalties are covered in the PSI guide. If the underlying problem is a missing or wrong plan, start with that guide.
Reconstruction is a collaboration, not a survey deliverable on its own. We measure and draw the structural layout as it can be observed: grid, column positions and sizes, beam layout and depths where visible, slab extents and levels, cores, staircases and openings. The PE then interprets that geometry, structural system, load paths, likely original design intent, and determines what further investigation is required. The drawing that results carries the PE’s authority, not ours.
Where finishes conceal the frame, the honest output is a partial layout with the concealed extents marked. Pretending otherwise produces a drawing that looks complete and is not, which is worse than a drawing that shows its gaps.
Cost is driven by floor area and number of levels, how much of the structure is visible, access and after-hours constraints, the drawing scope the PE specifies, and whether enlarged records of specific elements are required. Capture of a mid-size building is typically one to three days on site; the drawn records follow within one to three weeks depending on scope, and can be phased so the PE can start on the levels already delivered.
A PSI notice and no plans? Send the notice to get a quote: we scope the capture around the PE’s programme and the compliance deadline.
In most PSI jobs the managing agent controls everything that determines the schedule: keys, riser access, tenant notification, after-hours approval, lift usage and the contractor induction. So the practical order of work is to agree the access regime first and design the capture around it, rather than issue a survey programme that assumes the building will cooperate.
What we ask an agent for: a list of spaces with access constraints, the notification period tenants require, permitted working hours, whether escorts are needed for plant and risers, and a single point of contact on the day. What agents usually ask us for: proof of insurance, a method statement and risk assessment, and confirmation that capture is non-intrusive: no drilling, no opening up, no power required beyond a socket for charging.
Occupied buildings are routine. Handheld capture is quiet, needs no lighting changes, and leaves nothing behind. Where a tenancy declines access entirely, we record the exclusion in the coverage note so the PE can decide whether to pursue it: an honest gap in the record is manageable; an undisclosed one is not.
Send the notice, the building details and the access constraints together with your enquiry and the quote will reflect the building you actually have.
Engineers arriving on a PSI ask a predictable set of questions, and the survey scope is cheapest when it is written to answer them directly. Where is the structure, and how big are the members? Grid, column positions and sizes, beam layout and depths as finished, slab extents: the layout record.
What has changed since approval? Areas of alteration, added openings, removed walls, new mezzanines, changed loading patterns. This is where measured records earn their keep, because the approved drawing cannot show it.
What do the levels do? Floor-to-floor dimensions, transfer levels, splits and ramps: geometry that determines how loads travel and which elements deserve attention.
Is anything visibly out of line? Deflection, settlement, out-of-plumb and displacement that is geometrically measurable in a point cloud, reported as observation rather than diagnosis.
What could not be seen? The coverage note, which tells the PE where the record ends and their own investigation must begin.
Give us the PE’s brief, or their contact, and we will write the survey scope against those five questions rather than producing a generic drawing set that then needs supplementing. It is a shorter job and a cheaper one, and it lands in the format the report will actually cite.
Deadline, building type and PE’s brief reviewed; existing plan availability checked first.
Capture sequenced around occupancy, tenancies, after-hours windows and escorted areas.
Handheld SLAM through occupied floors and plant; tripod stations on elements needing tighter tolerance.
Structural layout, sections and levels drawn from the cloud to the PE’s conventions, with gaps marked.
Drawings, point cloud and coverage note to the PE. Assessment and report remain theirs.
| Deliverable | Format | Use in the inspection |
|---|---|---|
| Structural layout plans | DWG · PDF | Grid, columns, beams, slab extents as measured |
| Sections and level records | DWG · PDF | Floor-to-floor dimensions, transfer levels, changes in structure |
| Enlarged element records | DWG · PDF | Specific members or interventions the PE flags |
| As-built architectural set | DWG · PDF | Context for the assessment: via as-built documentation |
| Registered point cloud | E57 · LAS/LAZ · RCP | Re-measurable record; the PE can verify any dimension later |
| Coverage note | Inaccessible rooms, sealed voids and concealed extents, stated | |
| BIM model | RVT · IFC | Where the PE or owner wants a model: via Scan-to-BIM |
Geometry only. Reinforcement, cover, embedded steel, material strength and condition are investigation matters for the PE.
After the 5th year (non-residential) or 10th year (residential) from the last TOP or CSC, and it is notice-triggered. The duty arises when BCA serves a Notice of Inspection, not automatically on a calendar date. The “13th year” figure repeated on some sites does not appear in the Act.
No. The inspection is the PE’s statutory act. We supply the measured documentation the PE works from.
The owner’s PE can apply to buy BCA’s plans on the owner’s behalf. Where they cannot be obtained, BCA’s guidance contemplates reconstructing them: a measured survey supplies the geometry.
No. BCA states that recent or ongoing A&A works do not allow postponement, because A&A works do not include the independent inspection the Act requires.
No. Handheld SLAM captures occupied floors, plant rooms and basements in use. After-hours capture is arranged where public circulation makes daytime work impractical.
No, that is outside what a laser can measure and belongs to the PE’s investigation methods. We deliver geometry: member sizes as finished, spans, levels, alignment and visible interventions.
Yes. Send the PE’s template, sheet list and numbering and the records are produced in it.
Capture of a mid-size building is typically one to three days; drawn records follow within one to three weeks and can be phased so the PE starts on delivered levels while the rest is in production.
Yes. Handheld capture is quiet, needs no lighting change and leaves nothing behind. Tenant notification and after-hours windows are agreed with the managing agent, and any refused tenancy is recorded in the coverage note.
No. We produce measured layout records; the PE interprets them, decides what further investigation is needed, and issues anything that carries their authority. Reconstruction of missing plans is a collaboration, not a survey deliverable on its own.
We can report what is geometrically visible in the point cloud, out-of-plumb, sagging, level differences, as observation, with the measurement conditions stated. Diagnosis, cause and significance are the PE’s call.
Often the same building receives both notices. One mobilisation can capture the envelope and the interior structure together, which is cheaper than two surveys: see facade inspection support.