Painting take-off: working out the wall, ceiling and woodwork areas to paint

This guide follows French practice: French standards (NF DTU), French regulations and French bill conventions. Most sources are in French.

The items of a painting package and their units

A painting package breaks down into items that share neither the same unit nor the same rate. The bill of quantities almost always separates them as follows.

As with any package, the specification and the bill format set the unit of each item, what it includes and the rule for deducting openings. In France, NF DTU 59.1, the standard for thin, semi-thick and thick paint coatings (June 2013), says how the work is carried out; its special administrative clauses also help to define the painter's scope, notably on colours and contrasting cut-in lines. Painted elevations, for their part, are measured like render: see the elevation take-off.

Walls and ceilings, room by room

Measure room by room, the way the painter will work: the internal perimeter of the room, multiplied by its ceiling height, gives the gross wall area; the floor area of the room gives the ceiling area.

• Measure to the finished face of the walls, on the room side, linings and partitions included: that is the area the roller will cover, not the wall centre line.
• Take the ceiling height of each room. Finishing drawings often write it (“HSP 250”, i.e. 2.50 m); otherwise, read it on the section. A lowered ceiling in a shower room only changes the height of that room.
• A partition is painted on both faces, and each face is counted in its own room. Measuring room by room does this automatically; when partitions are taken by the linear metre, as in the partition take-off, two faces must be counted.
• Beam downstands, bulkheads, boxings: their girth is added to the wall or the ceiling, depending on what the contract says.

The ceiling follows the same logic: the room area, with voids and large openings deducted. Its perimeter, equal to the wall perimeter for a room without steps, is used for cornices or mouldings if the contract pays for them separately.

Openings, reveals and splays

Two rules exist side by side, and the contract decides:

• Actual area. Each opening is taken off, width × height of the opening; the reveals, which are painted too, are then counted in addition.
• Voids not deducted. Openings smaller than a threshold, expressed in m² per opening, are not deducted; the area counted in excess pays for the reveals and the cutting-in around the frame. The threshold has no universal value: it is set out in the specification or the bill.

The reveal is the return of the wall between its face and the frame. For a window, its girth is two heights plus the width of the head, the sill being dealt with separately; multiplied by the depth of the reveal, it gives an area. On a lined wall this depth includes the lining: take it from a detail or a section.

An internal door is treated differently: its frame fills the reveal, and it is usually counted with the door, among the joinery.

Woodwork and joinery: the developed area

A door is painted on two faces, with its edges, mouldings and frame. To pay for it without girthing everything, many contracts use a conventional developed area: the area of the joinery within its opening, multiplied by the number of faces and by a factor that grows with the relief. The painting specification of a public contract, listed in the sources, gives an example:

These factors belong to that contract; they are not a rule: other bills count doors per item, by model (single door, door with vision panel, cupboard door), and skirting by the linear metre. Radiators are often counted per item, by size, and exposed pipework per metre, by diameter. Note the convention you use at the top of the take-off: a “12” may be twelve doors or twelve m².

Preparation, finish and colours: separate lines

NF DTU 59.1 describes three finish levels, A, B and C, and the work stages needed to achieve them: preparatory work, filler coats, priming, then finishing. A more demanding level adds coats: it has its own line, or at least its own rate, and the take-off separates the rooms that do not have the same level.

In refurbishment, preparation (washing down, sanding, filling, stripping an old covering) is measured on the same area as the finish, but on its own line: it is not always done everywhere. The same goes for a wallcovering: hanging glass-fibre wallcovering and painting it are two lines with the same area. Wallpaper is ordered in rolls, but the bill usually counts the m² hung.

Finally, colours affect the rate. Under the special clauses of NF DTU 59.1, as presented by the French Building Federation (FFB), at most four colours are accepted for a site of less than 1,000 m² of painting, and per room one colour on the ceiling, two on the walls and one on the joinery; contrasting cut-in lines other than those of ceilings, door frames and skirtings may be priced separately. If the project includes them, take them off by the linear metre.

Worked example

A 3.60 × 3.20 m bedroom, ceiling height 2.50 m, with a 0.90 × 2.10 m flush door and a 1.20 × 1.35 m window whose reveals are 0.20 m deep. The specification requires the actual area (all openings deducted, reveals counted), doors as developed area, 2 faces × 1.30, and timber skirting by the linear metre (rules taken for the example).

Walls

Ceiling, door and skirting

The door is counted once, with both its faces, even though one of them faces the corridor. If the same contract applied voids not deducted to openings under 2.00 m² (threshold taken for the example), the door and the window would stay in and their reveals would not be paid separately: 34.00 m² of walls instead of 31.27 m², a difference of 2.73 m² in a single bedroom. And if doors were counted per item, the 4.91 m² line would become “1 u”.

The most common mistakes

• Walls measured on the centre line, or a single ceiling height for rooms that have several.
• Partitions counted on one face only.
• Openings deducted without their reveals, or left in as voids not deducted with reveals charged on top.
• A door counted twice, once in each of the rooms it separates.
• A developed-area factor applied out of habit when the contract counts doors per item, or the reverse.
• Preparation merged into the finish, or a single finish level for the whole project.
• Downstands, bulkheads and boxings forgotten.

Doing it in Kotelys

In Kotelys, each finish becomes a type (“Walls, eggshell paint”, “Glass-fibre wallcovering and paint”, “Ceilings, matt”): a name, a colour on the drawing, a total.

• Walls are drawn with the Length tool, following the outline of each room; a click and drag draws the outline of a rectangular room in one go. With the ceiling height given to the type, Kotelys writes out the area in full: “13.60 ml × 2.50 m = 34.00 m²”. A higher or lower room takes another type.
• Each opening is placed on the line with its own height: only its area is taken off. The “Openings not deducted below … m²” setting applies your contract's rule for voids not deducted to the whole type.
• Ceilings are drawn with the Area tool, voids as deductions (S key); the perimeter of each area is displayed, and repeated in the take-off calculations and in Excel.
• Doors and radiators are counted with the Count tool; skirtings and cut-in lines are drawn as Lengths.
• One zone per room or per flat, and the “Break down by zone” box of the reports splits every area. The take-off calculations write out every calculation, openings included (“− Opening 1: 1.20 × 1.35”); the Excel workbook gives the summary and the object-by-object detail.

Kotelys works out neither the reveals nor the developed area of the joinery: the calculations give the width and height of each opening, from which you derive the girth, and your contract's factor is applied in your pricing.

Further reading: painting take-off in Kotelys, and the other guides.

Sources

1. FFB, « Travaux de peinture : l'essentiel du NF DTU 59.1 » (finish levels A, B and C, work stages)
2. FFB, « Peintures : bien délimiter les prestations sur un chantier » (special clauses of NF DTU 59.1: colours, cut-in lines)
3. AFNOR, NF DTU 59.1 P1-1 « Revêtements de peinture en feuil mince, semi-épais ou épais » (June 2013)
4. Observatoire de la Côte d'Azur, CCTP lot 04 Peinture: example of a method of measurement (actual areas, joinery as developed area)

Thresholds and values described as “taken for the example” are not rules: those of your contract (specification, bill of quantities) always prevail.