Job takeoff
Central heating replacement takeoff
Replace a wet central heating system: dust sheets, scaffold where the flue needs it, lagging on pipes in cold spaces, the room the old boiler comes off repainted, and the skip, with the drain-down, the power flush before the new boiler, the boiler, flue, gas pipe, radiators, controls, inhibitor and commissioning listed and never certified.
A takeoff is the trade word for the shopping list a job produces — every material, and how much of each, worked out by its own cited calculator.
- 10Measurements in
- 4Trades out
Give the job once
Every figure on the right follows these, in the units you choose.
Been given a quote for this job?
Paste it into the central heating replacement quote check: each line is read against these same calculators — what it leaves out, what it adds, and what to ask.
Check the quoteEvery trade, from those dimensions
then change a dimension, and each line shows what moved.
| Trade | Quantity | |
|---|---|---|
Dust sheets in the rooms worked inMasking and Protection Materials CalculatorDust sheets over the floor of every room where a radiator changes or pipe is cut, and of the boiler's room, at the calculator's opening sheet size. Draining a radiator or cutting a pipe lets out black water that stains, so the sheets go down before the first valve is opened. The count covers the floors only; a folded sheet under each radiator as it comes off is one lifted from a finished room or one more bought. None is taped.
Why this quantity?
Resting on
Change any other figure on the Masking and Protection Materials Calculator | 9 items | |
Lagging on pipes in cold spacesPipe Insulation CalculatorFoam sleeves over the heating and hot-water pipe in the loft, a floor void, a garage or outside, and over the condensate pipe where it runs outside, with the calculator's allowance for bends: 1 m (about 3 ft 3 in) sleeves in metric and 6 ft (1.8 m) sleeves in imperial. The sleeve's bore and wall thickness are chosen for each pipe; the count follows the length alone.
Why this quantity?
Resting on
The bend and trim waste: the calculator's working figure, a trade convention. | 8 x 6 ft sections | |
Wall paint, two coats, in one roomPaint CalculatorTwo coats over the four walls of the room the old boiler comes off, less its doors and windows at the calculator's opening sizes, so the old boiler's outline, its bracket holes and the made-good flue hole do not show. Where units and tiles cover part of the walls, this is the most they take.
Why this quantity?
Resting on
| 1.66 gal | |
Skip (dumpster) for what comes outSkip & Dumpster Size CalculatorThe loose waste over the floor worked in at the depth you gave, as mixed construction waste: the old boiler, the radiators that change, a cylinder and loft tanks where the system becomes a combination boiler, the cut-out pipe and the packaging. Radiators, copper and an old cylinder that go to a scrap metal merchant come off it; the water flushed out goes to a foul drain, never into the skip.
Why this quantity?
Resting on
Change any other figure on the Skip & Dumpster Size Calculator | 1.77 yd³ | |
Dust sheets in the rooms worked inMasking and Protection Materials CalculatorDust sheets over the floor of every room where a radiator changes or pipe is cut, and of the boiler's room, at the calculator's opening sheet size. Draining a radiator or cutting a pipe lets out black water that stains, so the sheets go down before the first valve is opened. The count covers the floors only; a folded sheet under each radiator as it comes off is one lifted from a finished room or one more bought. None is taped.
Why this quantity? | 9 items | |
Lagging on pipes in cold spacesPipe Insulation CalculatorFoam sleeves over the heating and hot-water pipe in the loft, a floor void, a garage or outside, and over the condensate pipe where it runs outside, with the calculator's allowance for bends: 1 m (about 3 ft 3 in) sleeves in metric and 6 ft (1.8 m) sleeves in imperial. The sleeve's bore and wall thickness are chosen for each pipe; the count follows the length alone.
Why this quantity? | 14 x 1 m sections | |
Wall paint, two coats, in one roomPaint CalculatorTwo coats over the four walls of the room the old boiler comes off, less its doors and windows at the calculator's opening sizes, so the old boiler's outline, its bracket holes and the made-good flue hole do not show. Where units and tiles cover part of the walls, this is the most they take.
Why this quantity? | 6.05 L | |
Skip (dumpster) for what comes outSkip & Dumpster Size CalculatorThe loose waste over the floor worked in at the depth you gave, as mixed construction waste: the old boiler, the radiators that change, a cylinder and loft tanks where the system becomes a combination boiler, the cut-out pipe and the packaging. Radiators, copper and an old cylinder that go to a scrap metal merchant come off it; the water flushed out goes to a foul drain, never into the skip.
Why this quantity? | 1.35 m³ |
Also part of this job when you need it: Scaffold face for work at height — set scaffold along the wall below the flue above 0.
Also part of this job when you need it: Scaffold face for work at height — set scaffold along the wall below the flue above 0.
Estimates, not a quote. Each row gives its base, the allowance on top, the adjusted figure and what to order; change an allowance on the row, or open its reasoning to see every figure it rests on. A trade's own page carries what it does not cover — open the one you are about to order against.
Labour and programme
Person-hours for the rows going in, from trade rules of thumb: a range for each piece of work, never a price.
- Dust sheets in the rooms worked in3.6 h (1.8–7.2)
- Lagging on pipes in cold spaces0.8 h (0.4–1.8)
- Wall paint, two coats, in one room5.6 h (3.1–12)
- Skip (dumpster) for what comes out1.4 h (0.7–4.1)
About 11 person-hours in all, between 5.9 and 25.
Trade by trade
- Labourer1 labourerhalf a day
- Painter1 painterhalf a day
About 1½ days, one trade after another at eight hours a day. Left out: drying and curing, deliveries, inspections, trades overlapping.
Labour and programme
Person-hours for the rows going in, from trade rules of thumb: a range for each piece of work, never a price.
- Dust sheets in the rooms worked in3.6 h (1.8–7.2)
- Lagging on pipes in cold spaces0.8 h (0.4–1.8)
- Wall paint, two coats, in one room5.4 h (3.0–12)
- Skip (dumpster) for what comes out1.3 h (0.7–4.0)
About 11 person-hours in all, between 5.9 and 25.
Trade by trade
- Labourer1 labourerhalf a day
- Painter1 painterhalf a day
About 1½ days, one trade after another at eight hours a day. Left out: drying and curing, deliveries, inspections, trades overlapping.
Setups you have saved
The build-up, the dimensions and any allowance you changed — kept on this device, and reusable on any job. Your prices are not copied in: they stay in your price book, so a setup never holds a stale one.
How far does a budget go?
At your own prices, with this build-up unchanged.
About this job
Replacing a central heating system is a plumber's job with a gas engineer's work in the middle of it. The system is isolated and drained down to a foul drain before anything is cut, the old boiler comes off its wall once its gas is capped, and where the house changes to a combination boiler the hot-water cylinder and the tanks in the loft go as well. The pipework is altered for the new boiler's position, the new radiators and their valves go on it, and every joint is pressure-tested while it can still be seen; then the whole system, new radiators included, is cleansed and power-flushed before the new boiler is connected, so the sludge the old boiler lived with never reaches the new one's heat exchanger. The flue, the condensate pipe, the controls and a carbon monoxide alarm follow, and the system is refilled, dosed with inhibitor, balanced and commissioned.
Almost none of that has a quantity a page can measure. The boiler's output comes from a heat-loss calculation for the house, each radiator from the heat its own room loses, and the gas pipe's bore from the boiler's gas rate and the run's length in the gas tables: design figures, which this page leaves to the designer and the engineer. The flush and the inhibitor go by the system's whole water content, which no page adds up. The rows are the measured work round the heating instead: the dust sheets, a scaffold where the flue needs one, the lagging on pipes that cross cold space, the paint for the room the old boiler comes off, and the skip.
This is the job as it is done in Britain, and in any house heated by hot water: a gas or oil boiler feeding radiators through small-bore copper or plastic pipe. Across much of North America a house is heated by a furnace and ducts instead, and replacing one is another job with none of these rows; where a North American house does have hot-water heating, its boiler, its baseboard or panel radiators and its venting are this job, under the fuel gas and mechanical codes and a permit. The lagging and paint rows answer in each market's products: 1 m (about 3 ft 3 in) sleeves or 6 ft (1.8 m) sleeves, litres or gallons.
The gas work, the boiler, its flue and its commissioning are for a Gas Safe registered engineer in the UK, or a licensed fitter under a permit elsewhere, and nothing on this page stands in for their sign-off. In England a new boiler also brings a carbon monoxide alarm in its room, controls that fire it only when heat is called for, and in a hard-water area a scale reducer on a combination boiler; each is listed as work. The engineer's commissioning record and the building control notice are the papers a buyer or a landlord will ask for later, and they come from the engineer, not from this page.
How each line reads
- Base
- What the calculator gives for these dimensions, before anything is added.
- Allowance
- Cutting waste, a lap or spare stock — named, with where it comes from, and changeable on the row.
- Adjusted
- The base with its allowance on top.
- Order
- What to buy: the adjusted figure in whole boards, bags, rolls or lengths.
The order this happens in
Quantities do not tell you the sequence, and on this job the sequence is where the money goes wrong.
- Survey with the engineer before anything is ordered: the heat loss the new boiler and radiators are sized from, where the boiler and its flue can go, the gas pipe's run from the meter, and whether the old boiler, its flue or its cupboard is of an age to need an asbestos check.
- Sheet the rooms, isolate the gas, the boiler's electrical supply and the water, and drain the system down to a foul drain.
- Take out the old boiler, the radiators that are changing and, where the system becomes a combination boiler, the cylinder and the loft tanks, capping every redundant pipe.
- Core the flue hole, alter the pipework, hang the new radiators and fit their valves, and upsize or reroute the gas pipe where it needs it, lifting boards and drilling joists only where the rules allow.
- Pressure-test the new pipework and every radiator connection while each joint is in sight, then lag every pipe that crosses a loft, a floor void or the outside, and refill, cleanse and power-flush the whole system, new radiators included, before the new boiler is connected, or with it valved off.
- Hang the boiler and connect it, then fit its flue, the condensate pipe to a drain, the controls, and the carbon monoxide alarm in the boiler's room.
- Refill, dose the inhibitor, and have the engineer commission the boiler, test the gas, balance the radiators and record it all; the electrician tests any supply that moved.
- Make good the old flue hole and the pipe holes, repaint where the old boiler hung, clear the waste, and hand over the commissioning record, the notification and the maker's guarantee.
What this takeoff does not cover
- The heat-loss calculation and the system design: the boiler's output, the heat each room needs from its emitter, the pipe bores and the pump, which a designer or the engineer works out for the house. The site's heat-load and heat-output pages size them, and none is reached here.
- A hot-water cylinder changed or added, with its controls and its discharge pipe. Taking an old cylinder out for a combination boiler is listed; fitting a new one is a job of its own.
- The gas meter and the supply to it. An upsized or rerouted pipe from the meter to the boiler is listed as work; a larger meter or a new service is the gas supplier's or the network's.
- The commissioning record, the gas tightness test's paperwork and the building control notification themselves, and any fee for them. They come from the engineer and the scheme.
- Other fuel-burning appliances in the house: a gas fire, a back boiler behind it, an open-flued water heater or a cooker. They are checked by their own engineer; only the heating system is in this job.
- Radiators, valves, pipe, fittings and the flue as quantities. Each follows the design, so each is listed as work and none is measured; the lagging row counts only the pipe in cold spaces.
- Floor coverings lifted for pipe runs, and redecorating beyond the room the old boiler comes off.
- A change to a heat pump, which alters the emitters, the cylinder and the electrical supply and is a job of its own.
Quote check
Been given a quote for this job?
Paste it into the central heating replacement quote check. Every line of it is read against these same calculators and your measurements. Quantities only, never prices.
What it leaves out
Every line this takeoff has that nothing on the quote reads as.
What it adds
Labour, removal, hire, fees — each named for what it is.
What to ask
One list of questions, ready to copy. Never a verdict.
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Frequently asked questions
- What does the central heating replacement takeoff give for a typical job?
- Opened at Floor area of the rooms worked in 90 m² · Scaffold along the wall below the flue 0 m · Height to the flue's working platform 5 m · Pipe in cold spaces, each pipe counted 12 m · Room the old boiler comes off: length 4 m · Room the old boiler comes off: width 3 m · Room the old boiler comes off: floor to ceiling 2.4 m · Doors in that room 1 · Windows in that room 1 · Loose waste, as a depth over the floor worked in 0.02 m, it orders: Dust sheets in the rooms worked in, 9 items; Lagging on pipes in cold spaces, 14 x 1 m sections; Wall paint, two coats, in one room, 6.05 L; Skip (dumpster) for what comes out, 1.35 m³. Opened at Floor area of the rooms worked in 970 sq ft · Scaffold along the wall below the flue 0 ft · Height to the flue's working platform 16.5 ft · Pipe in cold spaces, each pipe counted 39 ft · Room the old boiler comes off: length 13 ft · Room the old boiler comes off: width 10 ft · Room the old boiler comes off: floor to ceiling 8 ft · Doors in that room 1 · Windows in that room 1 · Loose waste, as a depth over the floor worked in 0.59 in: Dust sheets in the rooms worked in, 9 items; Lagging on pipes in cold spaces, 8 x 6 ft sections; Wall paint, two coats, in one room, 1.66 gal; Skip (dumpster) for what comes out, 1.77 yd³. Every figure follows the dimensions you give it.
- Which calculators does the central heating replacement takeoff run?
- 4 calculators, one to a line: Masking and Protection Materials Calculator, Pipe Insulation Calculator, Paint Calculator, Skip & Dumpster Size Calculator. Each has a page of its own with its formula and its sources; the takeoff runs them all on one set of dimensions.
- What does the central heating replacement takeoff leave out?
- 8 things, each named on this page: The heat-loss calculation and the system design; A hot-water cylinder changed or added, with its controls and its discharge pipe; The gas meter and the supply to it; The commissioning record, the gas tightness test's paperwork and the building control notification themselves, and any fee for them; Other fuel-burning appliances in the house; Radiators, valves, pipe, fittings and the flue as quantities; Floor coverings lifted for pipe runs, and redecorating beyond the room the old boiler comes off; A change to a heat pump, which alters the emitters, the cylinder and the electrical supply and is a job of its own.
- Can I check a quote for this job against the takeoff?
- Yes. The central heating replacement quote check reads a quote's lines against these same calculators and your measurements, and reports what it leaves out, what it adds and what to ask. It reads quantities, never prices.