A badly handled survey on a renovation is never recovered on site. It is paid for in rework, in a unit that cannot be used, and in a phone call to the customer to move the date. You know how to hold a tape measure; that is not the question. The question is the order of operations and the points that decide the outcome. Deductions and tolerances depend on the product chosen: those get confirmed with us, never from memory.
Before the tape comes out, look at what is there
Start by observing.
Identifying the existing installation
A built-in box at the head of the reveal with the curtain behind it, a monobloc unit married to the joinery, an original window-and-shutter block, a shutter added to the outside of a seventies villa: these do not share the same dominant constraint. Open the box if it opens. Look at how the barrel is held, whether someone has been in before you, whether a makeshift screw is jamming an end plate. We regularly receive surveys that are immaculate on paper, taken on a box nobody had opened.
The intended product decides the method
Three families come up in renovation, each imposing its own reading of the opening:
- The traditional shutter put back inside an existing box. The constraint becomes the internal volume of the box and the room left for the roll.
- The monobloc, fitted with the joinery. Coherence with the new window and its frame governs the whole survey.
- The renovation shutter, face-fixed or under the lintel. Here the wall, the plumb and the obstacles outside dictate the measurement.
The choice follows from what is there and from the result expected. Our made-to-size roller shutter ranges cover all three, and a borderline configuration is settled beforehand, on the phone, before any material is cut. What each one means on site is set out in our guide to changing a roller shutter without opening a wall.
What to record, according to the intended fitting
The table below works as an aide-memoire on site. No values appear in it, deliberately: what changes is the priority of the survey, not the millimetres.
| Intended fitting | Record first | The point that decides the job |
|---|---|---|
| Traditional, inside an existing box | Internal volume of the box, real clearance between end plates, condition and position of the barrel, curtain height | The room available for the roll: it governs the choice of slat |
| Monobloc with new joinery | Bare reveal dimensions after removal, wall thickness, any lining or dry lining, planned frame position | Coherence between the block and the window ordered alongside it |
| Face-fixed renovation unit | The wall as substrate, plumb of the outer face, projecting obstacles, sill overhang, acceptable depth outside | What the fixing substrate is made of, and what projects around the opening |
| Renovation unit under the lintel | Clear height under the lintel, flatness of the lintel, return of the end plates, clearance left for the rails | The clear height under the lintel, which is almost always tighter than expected |
One opening can belong to two families. That is where a phone call saves a day.
The survey, point by point
Width and height, in several places
An old reveal is rarely square. Masonry that has settled, render made good three times over, a sill deformed by water, jambs that belly out. One measurement taken in the middle describes nothing usable. Take the width at the head, at mid-height and at the bottom; the height on the left, in the centre and on the right. On tall openings, put the tape away and work with a rigid rule: a tape that twists gives you a wrong figure delivered with confidence, which is far worse than an uncertain one. What governs manufacture is the least favourable value, the one that leaves the narrowest passage.
Send us the raw figures.
No averaging, no rounding, no deduction applied at your end. Deduction rules depend on the product and we give them to you; an installer who applies them before ordering creates precisely the problem they think they are avoiding.
“I’ve measured this way for twenty years”
That is the objection we hear most, and it is a fair one: an experienced fitter reads an opening before measuring it. The problem is not the skill, it is the handover. A correct figure inside a fitter’s head is worth nothing on an order form, because they are not the one cutting the profile. We manufacture what is written, not what was meant. So the survey is not an exercise in measuring, it is an exercise in communicating with the workshop.
Plumb, square, and flat end faces
The level goes against the jamb itself, not against a frame that is heading for the skip. Then check for square, and run a straight edge across the reveal faces and the back of the opening to find a lean or a belly in the render.
A known defect can be dealt with. A defect discovered on fitting day has to be endured, because a guide rail will not follow a deformed jamb without putting the curtain under strain.
Room for the rails, and what you are fixing into
A width that looks sufficient on the tape is not necessarily sufficient for the product. The rails take room on each side and reduce the final clearance. Check that the space on each jamb accepts the rail planned, allowing for whatever is staying: retained frame, trim, lining.
Then look at what you will be screwing into. Concrete, stone, hollow brick, shuttering block, timber frame, added insulation: the fixing follows from that, and a doubtful substrate is flagged at the order rather than at the moment the plug spins in the void. On villas in the hills it is not unusual to find a stone jamb on the left and recent dry lining on the right, on the same opening. Write it down. Those are two different fixings, and they are not improvised from a mobile tower. Note the aspect too when the opening faces the water: screws and attachment parts are not chosen the same way on shutters exposed to salt spray.
The sill, the upstand, the obstacles
This is the part most often forgotten.
A projecting sill or an upstand at the bottom changes how the rail terminates and how the curtain seats. Add to that whatever is lying around the opening: window handle, balustrade, downpipe, return wall, surface cable, hinged shutters the customer wants to keep. What is not reported is not anticipated, and gets discovered with a drill in your hand, in front of the customer, on a Friday afternoon. Take thirty seconds to write down everything that projects near the opening, including what strikes you as unimportant.
Roll direction, control side, and where the operation exits
Two lines that stop a production run
State which side the curtain rolls and which side the control is on. Above all, write down the point of view you are speaking from: without it, “on the right” is a coin toss. We would far rather have an order that says “right-hand side seen from inside” than one that says “as usual”.
Where the operation comes out
Strap, winder, cable exit, wired control run: the place where the operation passes through the box or the masonry is machined, and that machining cannot be moved afterwards. Record what exists, then report the real constraints: consumer unit at the other end of the room, dry lining, fitted furniture, return wall. An exit point chosen by default, without looking at the room, is always paid for at connection.
What a motor adds to the survey
The motor is prepared during the survey. Note the side wanted, whether there is a usable supply nearby, and the aspect of the façade if a solar solution is in play. With no supply available, radio control or a solar motor avoids chasing a wall the customer has just had repainted, and our comparison of radio solutions helps settle the choice before ordering.
The manual override
Check it will still be operable once everything is fitted. That access is reserved at manufacture, not at fitting.
Roll space, the constraint discovered too late
Inside an existing box, the question is not whether the shutter fits the width. It is whether the curtain has room to roll. The roll the curtain forms occupies a volume that depends on the height of the shutter and the slat profile chosen. When the box is too tight the roll rubs, the travel stays incomplete, the hatch no longer closes cleanly, and the customer rings you a few weeks after fitting thinking the motor is faulty. The motor has done nothing wrong.
Your survey therefore has to describe the inside of the box: usable volume, position and condition of the barrel, presence of an inspection hatch, any deformation. Those are what steer the choice of slat, not the other way round. On tight configurations, the right profile sometimes saves a box everyone had written off, particularly with the low-bulk solutions in the Vision+ range.
Photograph and annotate
One general view, one of each jamb, one of the sill, one of the box open, plus a dimensioned sketch in your own hand. It takes a few minutes and removes half the questions. When a joiner sends us that set with the order, we confirm or raise the alarm straight away, without four emails.
The survey sheet: what has to be on your order
| Information to send | Why it cannot be left out |
|---|---|
| Existing type of fitting and intended product | Determines the measuring method and the manufacture |
| Widths taken in several places | The least favourable value governs the product |
| Heights taken in several places | An out-of-square reveal makes a single measurement false |
| Plumb, square, flatness of the end faces | Decides whether the rails will sit properly |
| Space available for the rails | Avoids discovering at fitting that they do not go in |
| Usable volume of the existing box | Steers the slat choice and the roll |
| Nature of the fixing substrate | Determines the fixings and whether it is feasible at all |
| Projecting sill, upstand, obstacles | Changes how the rail ends and how the curtain seats |
| Roll direction and control side | Governs the machining; holds the job up if missing |
| Where the operation exits | Machined in the workshop, not changeable later |
| Motor, power supply, manual override | Determines the motor and the override access |
| Colour references | Avoids a shade mismatch and a wait for confirmation |
| Annotated photographs of the opening and the box | Confirm what the text does not say |
Copy that list into your notebook once and you will never read it again. A survey that ticks every line never comes back to us for more information.
The most frequent survey mistakes
Do I measure the opening or the existing shutter?
The opening, and the clearance genuinely available. Never the product in place: the existing curtain is smaller than the opening, and copying it condemns the new shutter. It tells you about the configuration, not about the dimensions.
What do I do when the reveal is out of square?
Record it as it is and report it. Adapted rails, a local repair, a change of fitting type: the solutions exist as long as the defect is known before manufacture.
Can the existing box be kept?
Often yes, if its usable volume allows the curtain to roll fully and the structure is sound. To be plain about it: this is the point on which we most often ask for a photograph before confirming an order.
Why is a height taken from the sill a problem?
Because a projecting sill or an upstand shifts the starting point of the measurement. We see rails ordered short for that reason alone. Always state the level you measured from.
In doubt about a dimension? Call before you order
The rule fits in one sentence: anything that makes you hesitate on an opening is settled before the order, not during the fitting. A three-minute call with two annotated photographs costs less than a curtain remade, and you know that already. The real question is whether you take up the habit on your next job.
Send us your survey and your photographs and we will tell you what is feasible and what needs a decision — start here. On a job at Saint-Laurent-du-Var or higher up the valley, a check on site remains possible; the simplest thing is to say so when you send the survey.
For a project in Saint-Laurent-du-Var, see our page on roller shutters in Saint-Laurent-du-Var.
