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What measurements does the painter need, and what does the flooring fitter need?

The painter works in net wall area, ceiling area and number of coats. The flooring fitter works in floor area plus waste and running metres of skirting. The carpenter works in running metres and item counts. Here is what each trade needs — and what each of them cannot use.

Why the trades can't use the same figures

Every tradesperson prices quantity times unit price, but the three trades work on different geometries. The painter works on surfaces, the flooring fitter on one surface plus its edge, and the carpenter on lines and items. So the same takeoff can be perfect for one and useless for another.

A takeoff that says nothing more than "the living room is 15 m²" is, in practice, no use to any of them: the painter is missing the walls and the height, the flooring fitter is missing the pattern and the subfloor, and the carpenter is missing everything.

The painter: surfaces, coats and the surface underneath

Needs:

• Net wall area per room — perimeter times ceiling height, minus doors and windows. Give the gross figure in brackets too, so the painter can choose; some painters don't deduct small openings, because the trim around them costs more work than the surface saved.
• Ceiling area. In a room with a flat ceiling this equals the floor area. With sloped ceilings it's substantially larger, and then the knee-wall height and the ridge height need to be included too.
• Ceiling height, measured in three places. An 8 cm error over 15.6 running metres of wall is 1.25 m².
• Number of openings — reveals are often priced per item, not per square metre.
• Running metres of skirting, architrave and door leaves, if they're to be painted too.
• Condition of the surface: lining paper, felt, layers of wallpaper, bare plasterboard, cracked render. This is where the hours are.
• Number of coats and the desired sheen.

Cannot use: the area from the official public building register — it's measured externally, with the walls counted in, and so is larger than the surfaces to be painted — nor a floor area on its own, which says nothing about how high the ceiling is.

The flooring fitter: area, pattern and everything under the floor

Needs:

• Floor area per room in internal dimensions, wall to wall, minus fixtures that don't need flooring underneath.
• The room's shape — alcoves, bay windows and irregular corners change the waste noticeably.
• Laying pattern: straight, diagonal or herringbone. Typically 5-10% waste for a straight lay in a rectangular room, closer to 10-15% for herringbone, diagonal, or a room with many corners. State the area, and let the flooring fitter add their own waste allowance.
• The subfloor: concrete, old boards, chipboard — and whether it's level. Levelling and screeding is its own, often overlooked, line item.
• Running metres of skirting after deducting doorways, plus the number of corners.
• Number of door thresholds and which floor types meet there.
• Whether there's underfloor heating — it limits which flooring types can be used.
• Clear opening height under the doors, if the new floor builds up in height — a new floor at 14 mm plus underlay can mean the doors need trimming.

Cannot use: a wall area, nor a floor area without the room's shape — the perimeter and the corners cannot be derived from square metres alone.

The carpenter: lines and items

Needs:

• The actual length of every wall, not just the room's two outer dimensions. It's the wall segments that make up the running metres.
• The width, height, sill height and distance to the nearest corner of every opening. A door 30 cm from the corner and a door centred on the wall are two different jobs.
• The room height, if new partition walls are to be built — walls are typically priced per running metre at a given height.
• Item counts: number of doors, reveals, shelves, mouldings, corners.
• Existing wall thicknesses, if something is to be built onto them or an opening closed off.

Cannot use: areas on their own. A 15 m² room can have anywhere from four to nine wall segments, and that difference is the carpenter's whole sum.

What all three trades need — and what often gets forgotten

• The ceiling height, measured in three places, with the lowest and highest given rather than an average.
• Photos, two or three per room. They often save a site visit.
• Access conditions: floor level, lift, parking, whether long materials can be carried up the stairs.
• Whether the home is furnished and occupied during the work.
• When the work needs doing, and when you want an answer by.

What none of them can tell from measurements

Whether a wall is load-bearing. Not the painter, not the flooring fitter, not the carpenter, not a tape measure, and not a LiDAR scan can determine that — a scan measures a wall's thickness and position, not what rests on it. If a wall is to be removed or opened up, a building surveyor or an engineer needs to assess it, and that kind of work normally needs approval from the authorities before it starts. Write it down as an open question rather than let an assumption stand in the quote.

One takeoff, three enquiries

The good news about the lists above is that they overlap. Measure once and gather net wall areas, floor and ceiling areas, ceiling heights, the length of every wall and the size and position of every opening, and you have the foundation for all three trades. You just need to highlight the right part in each enquiry — and add the trade-specific piece: the surface condition for the painter, subfloor and pattern for the flooring fitter, item counts for the carpenter.

HouseSense gathers exactly that shared core. Scan the home with LiDAR on an iPhone Pro — or draw it on the graph paper — and the app's takeoff works out net wall areas with doors and windows deducted, totals the floor and ceiling areas and ceiling heights, and lists every opening in a window and door schedule with width, height and position. The floor plan and takeoff can be sent as a PDF, and the PDF can be written in a different language from the app's, if the tradesperson doesn't read English.

The rest is your own words: what needs doing, what the surface looks like, and when you want an answer.