15 Minutes Saved per Blind by a Bosch PLR 40 C Laser on a 5-Window Survey

Five recesses, measured to the millimetre, in under ten minutes: that is the working claim for the Bosch PLR 40 C on a blind survey that would take much longer with a folding rule and pad. The 40 C has a stated 40 metre range and 2 mm accuracy, and each reading can be sent over Bluetooth to the Bosch MeasureOn app.

In a manual survey, a fitter reads the rule, calls or repeats the number, writes it in a column, then may see the same figure typed into an order later. Many recess errors begin somewhere in that chain. Cutting out the handwritten transfer is what makes a saving of roughly 15 minutes per blind believable on a five-window job, especially in awkward recesses, tall bays and any opening where a tape would usually need a second pair of hands at the far end.

Where MeasureOn changes the survey

A laser distance meter alone saves seconds with each shot. MeasureOn turns those seconds into a different record: every measurement transfers with a timestamp, and the fitter can attach it to a labelled opening inside a floor sketch on the phone.

The routine on a five-window survey repeats quickly. Width is taken at the top, middle and bottom; drop is taken on the left, centre and right. Those six readings per opening sit against the correct window as a digital record from the start.

Trade guidance for recess measurement has long said to measure width in three places, use the smallest figure and avoid assuming that the reveal is square. Plaster reveals rarely behave that neatly. Where the head and the sill differ by even a few millimetres, that gap can decide whether a rigid roller tube binds against the reveal, so the head and sill values need to remain separate in the record.

The PLR 40 C captures the head and sill readings during the same movement a fitter would use to capture one reading by hand. In the worked example with three vertical openings, the three-point width and three-point drop routine produces eighteen readings before the bay and roof window are added.

Sequence matters once the job moves from survey to ordering. The phone keeps the figures attached to W1, W2, W3 or any other labelled opening, and the stored file survives the van journey back.

A notepad column headed W3 with one smudged digit has caused more than one blind to be remade. The digital file does not make the fitter immune to error, although it removes one of the common places where a correct measurement becomes a wrong order.

Velux ordering starts with the frame code

A Velux roof window blind fits by sash frame code. The plaster opening does not set the blind size. The code is on a data plate along the top of the sash, visible when the window is opened, and it appears as a letter and number pair such as MK04 or UK08.

That code determines the blind. A laser reading of the aperture gives little useful ordering information for a fitted Velux blind because the blind clips to a manufacturer-dimensioned frame profile.

The PLR 40 C still earns its place near the roof window through reach. Measuring the room drop from a fixed pleated blind to a sill, or checking headroom for an electric Velux blind motor and its bracket, involves the kind of vertical distance that is awkward by hand at ceiling height.

The 40 C can shoot from floor to sash and log the distance. The frame code still has to be read by eye and entered by hand, because it comes from the data plate.

The diagonal still belongs to the tape

Squareness stays outside the laser’s reach. A recess can produce two clean width readings and still be out across the diagonal, so the corner-to-corner check remains a manual tape job.

Motorised tracks, handles and power points

A manual roller blind needs width and drop. A motorised blind track or tube adds clearance checks that have to be captured before the order is placed.

Motor clearance at one end of the tube, usually around the head rail, means the recess must be checked for housing depth as well as blind face width. A Somfy or Louvolite motor tube adds diameter that has to clear the reveal and any window handle standing proud of the frame.

Handle projection is easy to underestimate by sight. On a tilt-and-turn window, it is the distance the handle protrudes from the glass line into the recess. Shot from the reveal face to the handle tip, it becomes a recorded figure.

A tilt-and-turn handle can eat a large share of the available reveal depth, and a motorised tube then has to fit in what is left. If the projection is missed, the tube can foul the handle at the fitting visit. Capturing the projection during the survey catches that clash while the order can still be changed.

Electrical details sit in the same record. A mains motorised track needs a fused spur near the head of the recess, and the record should include the nearest socket or spur distance. A battery tube avoids the spur and creates a charging access requirement. Both details belong in the same MeasureOn opening record so the ordering desk can see the full specification for that window.

Silent Gliss curtain track often appears on the same kind of survey. A ceiling-fixed Silent Gliss 6870 wave track is measured by the drop from track to floor plus the return at each end. A laser floor-to-ceiling shot removes much of the stepladder-and-tape routine for the drop, while bracket spacing is still set out by hand along the fixing line.

Condensation notes can change the blind specified

A blind changes airflow across a window. A tight blackout blind fitted hard against a cold single-glazed reveal can trap moist air against the glass.

Condensation risk has to be recorded during the survey because it can change the specification sent from the desk. The Building Research Establishment has long linked persistent surface condensation on window frames with restricted air movement and cold bridging at the reveal.

Bathrooms and kitchens make that note especially important. The fitter records whether the opening has single glazed timber, secondary glazing or a modern sealed double glazed unit, since each behaves differently once a blind is fitted in the recess.

A honeycomb blind with side channels seals the airspace very effectively. That can help heat retention, yet it can also worsen the conditions behind a blind on a window that already streams with condensation each morning.

The same recess dimensions can therefore lead to different blind recommendations once the frame note is attached. Without that note, the order can look complete while missing the condition that affects how the blind will behave in use.

The laser cannot read humidity. The time it saves can still give the fitter enough margin to open the window, check the reveal for existing mould staining and record the frame condition against the correct opening. On a rushed manual survey, that observation is often the first detail to disappear.

The five-window timing claim in practice

Take a mixed job: three vertical recesses, one bay with two lights and one Velux. With a folding rule and pad, each vertical opening still means six readings, but the slow part is not the reading. It is the calling out, writing down and re-checking of each figure, repeated for every opening, plus the return climb up a stepladder for the Velux drop and the angled returns in the bay. On a job that size the manual method eats a chunk of the morning before the diagonal or handle checks are even started.

With the PLR 40 C and MeasureOn, the pattern changes because the writing-down stage disappears. Each of the six vertical readings transfers to the labelled opening as it is shot, so the fitter is not looking down at a pad between measurements. Bay returns come off the reveal faces directly, the Velux drop is a single floor-to-sash shot logged in place, and only the frame code has to be typed in by hand. The saving is not one big block of time in one place. It is a smaller amount removed from every reading, plus the whole transcription step, and it multiplies across five openings.

The remake cost is the larger issue behind the labour saving. A roller blind cut oversize because a 4 was read as a 9 on a smudged pad becomes a full reorder, which can outweigh whatever the survey itself saved.

What remains in the fitter’s hands

Every PLR 40 C reading is a straight distance. Squareness, the interpretation of handle projection, frame condition, Velux frame codes and draught proofing checks on sash windows still depend on the person carrying out the survey.

A sash window survey still includes the meeting rail gap and the parting bead for a brush-pile route. A laser does not report a worn staff bead.

The laser removes one class of error and speeds one part of the work, but the judgements that decide whether a blind fits and behaves well are still made by eye and by hand. What it cannot tell the fitter is which of those judgements a given recess will turn on before the tape and the ladder come out.