Craft Quantities
Plan & Takeoffs

Quote check

Check a cavity wall insulation quote

Paste the quote you were given and enter your measurements. Every line is read against the job: what the quote leaves out, what it adds, which quantities sit outside the computed range, and what to ask. Quantities only — never prices.
  • 1Line the job needs
  • 5Measurements
  • QuestionsNever a verdict

How the quote is read

Each line of a cavity wall insulation quote is matched to the line of the job it names, or marked as something the Cavity wall insulation (retrofit fill) takeoff does not measure — labour, removal, hire, fees, or anything else. Work the takeoff lists as part of the job but gives no quantity for is read as that work, not as something the quote adds.

The job’s own figures come from 5 measurements — length of wall filled, every elevation end to end, height filled, windows and doors in the walls filled, opening width, average, opening height, average — run through the same calculators as the takeoff, so the two give the same figure for the same job.

Reading a cavity wall insulation quote

A cavity wall insulation quote is worth reading for the wall it assumes. Worth asking who surveyed the walls and how, through test holes with a borescope or bay by bay, what was found about the width and cleanliness of the cavity or the blocking in the bays, and whether any wall was left out and why. Where a quote names no survey, worth asking whether one is part of it before any hole is drilled.

This check compares the fill in bags or bales. A quote that prices it by the area of wall instead can be held against the wall area, openings deducted, that the full takeoff prints beside the bags in the fill row's working, one link away. Worth having the product named by make, its installed density and the number of bags or bales it expects to blow, so the figure can be set against the installer's record afterwards; and worth asking how the holes are closed, in a mortar matched to the joints or with plugs and the siding put back, and how the fill is checked once it is in.

The paperwork is the other half of the job. In Britain, worth asking who notifies building control and whether a guarantee comes with the work, who issues it and whether it is insured; in North America, whether a permit is needed and who pulls it. Worth confirming as well whether the air bricks are sleeved and the party line closed, whether old siding is tested for lead or asbestos before it is drilled, and whether any open-flued boiler, fire or stove is spillage-tested once the walls are filled, and by whom.

Three steps

  1. Give your measurements. The page opens on a typical job so it has something to show.
  2. Paste the quote's lines as they came, or add them one at a time. Leave the prices in — they are taken out, never read.
  3. Read the report: what is left out, what is added, what sits outside the range, and one list of questions to send.

Your quote

The cavity wall insulation quote you were given

Paste from an email, or open or drop a PDF, Excel, CSV or text file, or a photo of the quote. Amounts of money are taken out before anything is read — this page compares quantities, never prices.

Nothing you paste or open leaves this device.

or one the job needs:

The reading

What the quote says, against the job

Cavity wall insulation · Length of wall filled, every elevation end to end 72 ft · Height filled 15.5 ft · Windows and doors in the walls filled 10 · Opening width, average 3.5 ft · Opening height, average 4.5 ftLength of wall filled, every elevation end to end 22 m · Height filled 4.8 m · Windows and doors in the walls filled 10 · Opening width, average 1.1 m · Opening height, average 1.3 m

  • What it leaves out

    Every line the job needs that nothing on the quote reads as, with the quantity your measurements produce.

  • What it adds

    Lines this job's takeoff does not measure — labour, removal, hire, fees, anything else — each named for what it is.

  • What sits outside the range

    Quantities above or below the computed range, by how much, in the quote's unit or converted and shown.

  • What to ask

    One list of questions, in the quote's order, ready to copy and send. Questions, never a verdict.

Paste the quote above, or add its lines one at a time. The reading appears here as each line is read.

Outside what this takeoff measures

11

Nothing in the reading measures these. Whether the quote covers each is worth asking in its own right: a scope missing from a quote tends to become a cost after work has started. Why each is left out is on the takeoff.

  • Judging the cavity suitable (the installer's call)
  • Cavity extraction, taking out an old or failed fill
  • Wall tie replacement or renewal
  • Damp or rain found afterwards (flagged)
  • Knob-and-tube rewiring
  • Abatement or encapsulation
  • New cladding boards (re-siding the house)
  • Roof-space (attic) work
  • A gable's triangle above the eaves line, unless its area is added to the length as that figure's help says
  • Repointing the outer leaf, or putting its cracks right, where the survey asks for that first
  • Trickle vents or extract fans that a tighter house may need afterwards

The reference

Every line the reading looks for

For Length of wall filled, every elevation end to end 72 ft · Height filled 15.5 ft · Windows and doors in the walls filled 10 · Opening width, average 3.5 ft · Opening height, average 4.5 ftLength of wall filled, every elevation end to end 22 m · Height filled 4.8 m · Windows and doors in the walls filled 10 · Opening width, average 1.1 m · Opening height, average 1.3 m. Each is the calculator linked under it, run with those measurements; a range is that calculator at both ends of one choice, not a margin for error.

How the ranges are taken

Where the choice is cutting waste, the ends are the site’s own allowances: 5%, the tight buffer of a crew with a planned set-out, and 15%, the wider one a first-timer orders. Where the calculator decides between patterns or materials, the ends are the options it offers. Where it adds nothing for loss, the range runs from the net quantity to 15% over it.

A minimum — the fewest hangers a spacing allows, the least airflow a room needs — has no upper end. A single figure carries an allowance the material itself needs, such as a lap, and names it.

What a reading like this cannot see

  • It does not know your prices, your market, or what the work ought to cost.
  • It does not know the building — the access, the condition of what is there, or what has to happen first.
  • It cannot check a lump sum, because there is no quantity in one.
  • A line it reads as missing may be priced under another name. A quantity outside the range is not evidence of anything. Each is a reason to ask a question.
  • Two quotes are not comparable until their scopes are.
  • It is not advice, and it is no substitute for a second quote.

The full takeoff

Every quantity for this job, with its working

The Cavity wall insulation (retrofit fill) takeoff runs the same calculators on the same measurements and shows what sits under each line here.

Open the takeoffEvery quote check

  • Base, allowance, order

    Each line's quantity before and after its allowance, and what to buy.

  • Every allowance editable

    Change a waste figure and the order follows, with its source named.

  • Into a project

    Add the whole job to a workspace with your own prices.

Frequently asked questions

What quantities does a cavity wall insulation job need?
It depends on the measurements, so this page asks for yours. At the size it opens on — Length of wall filled, every elevation end to end 22 m · Height filled 4.8 m · Windows and doors in the walls filled 10 · Opening width, average 1.1 m · Opening height, average 1.3 m — the lines come to: Cavity fill, blown-in bead, wool or dense-pack cellulose (bags or bales), 10–12 bags. In imperial units — Length of wall filled, every elevation end to end 72 ft · Height filled 15.5 ft · Windows and doors in the walls filled 10 · Opening width, average 3.5 ft · Opening height, average 4.5 ft — they come to: Cavity fill, blown-in bead, wool or dense-pack cellulose (bags or bales), 30–34 bags.
Which line on a cavity wall insulation quote varies the most?
The Cavity fill, blown-in bead, wool or dense-pack cellulose (bags or bales): 10–12 bags for a job measured Length of wall filled, every elevation end to end 22 m · Height filled 4.8 m · Windows and doors in the walls filled 10 · Opening width, average 1.1 m · Opening height, average 1.3 m, depending on the waste allowance allowed, from 0% to 15%.
What does a cavity wall insulation quote often leave out?
The reading names every line of the job that nothing on the quote reads as — the one line the takeoff measures. The takeoff also lists 11 things it does not measure, shown under the reading, and each is worth asking about: a scope missing from a quote tends to become a cost after work has started.
Can I paste the quote exactly as it came?
Yes — from an email, a PDF or a spreadsheet, one item to a line. Amounts of money are taken out before anything is read, headings and totals are skipped, and each line is shown with what it was read as, so a misreading is one correction. Quantities in the other unit system are converted and the conversion is shown; a count of boxes is never compared with a count of tiles.
Does this check the price as well?
No. It reads quantities, never prices, and this site publishes none: an installed price moves with the market, the season, the access and the specification, so a figure for what the work ought to cost would give you confidence in a number nobody can defend. A quantity against your own measurements is checkable, and every figure here links to the calculator that produced it.