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3D scanning and opening surveys

Laser 3D scanning and survey of every opening on site. Doors are manufactured to as-found dimensions, not design dimensions — and the general contractor receives a list of openings that need remedial work before production starts.

Point cloud of a wall section with two door openings after laser scanning D-2.14D-2.15101210101008REVEAL: DEVIATION +4 MMfrom vertical over opening heightWIDTH AT THREE LEVELS1012 · 1010 · 1008 → 1008 usedWALL THICKNESSin the point cloud — around the whole openingFINISHED FLOOR LEVELlevel difference at the thresholdDPSPoint cloud · extractopening marks as per specification3D SCAN · FLOOR 2 · GRIDLINES 3–5
Point cloud extract: a wall with two openings after scanning. Each opening is tagged with its specification reference, and dimensions are taken directly in the model — accurate to the millimetre, with no guesswork.

Why scan instead of using a tape measure

01

An opening is rarely square

The width differs at the bottom and top, the reveals lean, and the floor at the threshold is uneven. A tape measure gives one figure; a scan captures the full geometry.

02

A survey error means a remade door

A fire-rated door is made to size. If the frame will not fit the opening, it cannot be trimmed on site — and that costs weeks and money.

03

Hundreds of openings in one visit

The scanner captures an entire floor. Openings that are not yet ready go straight onto a deviation schedule for the general contractor.

How we survey an opening

Door opening survey diagram: width and height at three points, diagonals, plumb, floor ±0.000 finished floorB1B2B3H1H2H3D1D2plumb lineB1 · B2 · B3width at bottom, middle and top —the smallest value is usedH1 · H2 · H3height from finished floor at the leftreveal, in the centre and at the rightD1 · D2diagonals — show if the opening is skewedPLUMBreveal deviation from vertical andwall plane leanTwall thickness at several points aroundthe perimeter±0,000finished floor level and step at thethresholdDPSEach dimension — at 3 pointsrecorded in the survey scheduleOPENING SURVEY DIAGRAM
Every dimension is taken at a minimum of three points. For width and height the smallest value is used — that is what the frame, plus its installation gap, must fit into.

What we check in every opening

ParameterTypical requirementWhy it matters
Width and heightat 3 points; variation no more than 10 mmthe frame is made to the smallest dimension
Plumb of revealsno more than 1.5 mm per 1 m of heightotherwise the leaf drops and will not self-close
Level of headno more than 1.5 mm per 1 m of widthskew causes uneven rebate contact and gaps
Difference in diagonalsno more than 5 mma racked opening transfers to the frame
Wall flatness at the openingno deviation over 3 mm per 1 mthe architrave must sit on the wall without a gap
Wall thicknessat 3 points up each reveal and along the headframe depth, extension liners, anchor length
Reveal angle to wall face90° — no acute or obtuse anglesthe only way to get an even gap and a tight architrave
Floor at thresholdfinished floor level set, variation no more than 5 mmthresholds and drop seals only work on a level base
Installation gap10 to 30 mm — increases with the height and weight of the unitspace for anchors and fire-rated joint sealing
Wall materialcast concrete, brick, block, plasterboard with embedded fixingsanchor type and spacing, opening reinforcement

Values are DPS typical opening readiness requirements. For a specific product, the tolerances in its data sheet and installation instructions apply; these are stated in the schedule for each opening.

Opening reveal: exactly 90°

A reveal is not just a hole in the wall — it is the seat for the frame. It must sit at a true right angle to the wall face. An acute or obtuse angle is invisible to the eye but shows up immediately on installation: the gap becomes tapered, the anchor goes in at an angle and the architrave stands off the wall. That is why we measure wall thickness and the angle of each reveal separately, at three points up its height.

Plan section through a reveal: 90° is correct; acute and obtuse angles are defective openings90°90°T10–3090° — CORRECTThe frame sits with an even gap,the architrave lies flat on the wallwall plane≈ 79°wedgeACUTE ANGLE — DEFECTWedge-shaped gap: the joint can't be filledevenly, the anchor works in bendingwall plane≈ 100°stopOBTUSE ANGLE — DEFECTThe reveal eats the gap: the framehits the wall, the leaf will rackwall planePlan section: wall, reveal, frame with anchors. T — wall thickness, measured at three points along the height of each reveal.
The same opening in three variants. A 10° angle deviation in a 200 mm wall already means a 35 mm difference in reveal depth.

Fixings are selected at the survey

A fire-rated or oversized door can weigh from 80 kg to several hundred kilograms, and a gate leaf more than a tonne. It is the wall, not the frame, that carries it. So we define the fixing scheme at the survey, not at installation.

01

Weight and size of the unit

The taller and heavier the product, the more fixing points and the wider the installation gap — from 10 mm for a standard door to 30 mm for tall, heavy units.

02

Wall material and condition

Cast concrete, brick, aerated concrete, hollow block or plasterboard — each substrate needs its own anchor. We determine the material, thickness, and any voids or spalling at the edge of the opening.

03

Anchor type, spacing and quantity

Frame plugs, mechanical or chemical anchors, embedded fixings. For weak substrates we specify steel subframe reinforcement of the opening from the outset.

How the work is done

  1. Visit preparation

    We obtain plans with opening references and levels, and agree access and the sequence of floors.

  2. Scanning

    The laser scanner captures the floor from several stations. In parallel, we photograph the openings and junction details.

  3. Point cloud processing

    We register the stations into a single model and tie it to the building grid and levels.

  4. Survey in the model

    We take the dimensions of each opening to the scheme: width, height, diagonals, plumb, wall thickness, reveal angle, floor.

  5. Cross-check and fixings

    We compare as-found dimensions against the specification, flag out-of-tolerance openings and select a fixing scheme for the product weight and wall material.

  6. Schedule and re-inspection

    We issue the general contractor with a list of remedial works; after correction we re-survey only the problem openings.

What's included

  • Engineer site visit
  • Laser 3D scanning of rooms and openings
  • Survey of every opening to the scheme: width and height at three points, diagonals, plumb of reveals, wall thickness, reveal angle to wall face, floor
  • Identification of wall material and selection of fixings for the weight of the unit
  • Cross-check of as-found dimensions against the design and specification
  • Photographic record of openings and junction details
  • Deviation schedule and recommendations for opening preparation
  • Re-inspection of openings after remedial work

Result

Point cloud and 3D model of the area, a schedule of as-found dimensions and a fixing scheme for each opening, plus a list of openings the general contractor needs to correct — stating exactly what and by how many millimetres.

What we need from the client

  • Site access for the engineer and an escort
  • Completed walls and formed openings
  • Floor plans with opening references
  • Finished floor levels and setting-out grid lines

Timing and cost depend on the scope of work and are calculated for each project.

Let's discuss your project

Send us your documentation or door schedule — we will reply with a scope of works and costing.

Phone: +7 958 644 06 47