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Part 3 of 7 · Quote comparer series ~6 min read

How quotes get made comparable

The instinct is to line the three quotes up against each other, and it does not work, because they have different numbers of lines describing different groupings of work. The trick is to compare each one against the thing you asked for, separately, and then compare the results.

Key takeaways

  • Align each quote to the requested scope, not to the other quotes.
  • Every scope item ends up included, excluded, or unclear — never silently absent.
  • Unit conversion needs the spec’s quantities; a quote saying “the bathroom” is not a number.
  • Exclusions come from three places: stated, implied by omission, and buried in terms.
  • An assumption in a quote is a price condition, and it belongs in the comparison.

Compare against the ask, not each other

Three differently structured quotes aligned against one requested scopeThree boxes stacked on the left. Quote A with one line, supply and fit, labelled sparse. Quote B with twenty-two itemised lines, labelled detailed. Quote C with fourteen lines plus two terms pages, labelled detailed. All three converge on The requested scope, which has nine items taken from the spec, and that leads down to Three alignments, with each scope item resolved. A note says nine rows, three columns, every cell filled, and nothing is left implicit.Quote A -- 1 linesupply and fitsparseQuote B -- 22 linesitemiseddetailedQuote C -- 14 linesplus 2 terms pagesdetailedThe requested scope9 items, from the specThree alignmentseach scope item resolvedNine rows, three columns, every cell filled. Nothing is left implicit.
Fig 1. Why alignment runs through the scope. Three quotes with one, twenty-two and fourteen lines have no common structure; the requested scope does.

Three outcomes per cell, never two

For each scope item and each quote, the answer is included, excluded, or unclear. The third one is essential and is what most comparison spreadsheets lack: a blank cell means either “they did not include it” or “nobody knows”, and treating those as the same thing produces confident conclusions from missing information.

Scope itemQuote AQuote BQuote C
Remove existing suiteUnclear — not mentionedIncluded — p1 l3Included — p1 l2
Tiling, 11m²Included — in “fit”Included — p2 l9Included — p1 l7
Waste removalExcluded — terms, p1Included — p3 l4Unclear — not mentioned
Making good wallsUnclear — not mentionedIncluded — p3 l1Excluded — terms, p5
Electrical certificateUnclearExcluded — p4 l2Included — p2 l11

That table is the product. It took the reader and the normaliser to produce and anyone can act on it: three specific questions for quote A, one for quote C, and a clear picture that quote B is the one being compared against.

Units need the spec

A quote saying “tiling — the bathroom — £840” has no unit price until something supplies the eleven square metres, and that something is the original spec rather than the quote. This is why the requested scope is an input to the system rather than something inferred from the documents.

Where the spec does not give a quantity, the unit price is left uncomputed rather than estimated. A per-square-metre figure derived from a guessed area is precisely the kind of number that gets quoted back in a negotiation and cannot be defended.

Where exclusions hide

The four places exclusions hide in a supplier quoteA vertical chain of five steps entered by a box labelled A quote, fully read, with lines and terms. Step one finds stated exclusions, phrased as excludes something, with a side note saying these are easy and rare. Step two finds scope items that are absent, asked for but not mentioned, with a side note saying these are unclear rather than excluded. Step three finds conditional prices, such as assumes clear access. Step four finds provisional sums, such as allow four hundred for tiles. Step five puts all four in the table with their wording. A note says the second and fourth are where a cheap quote usually turns out not to be.AWS ACCOUNTA quote, fully readlines and termsStated exclusions'excludes...'Easyand rareScope items absentasked for, not mentionedUnclearnot excludedConditional prices'assumes clear access'Provisional sums'allow 400 for tiles'All four, in the tablewith their wordingThe second and fourth are where a cheap quote usually turns out not to be.
Fig 2. The four kinds of exclusion, in the order they are easy to miss. Provisional sums in particular read as included and are not.
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Provisional sums deserve their own treatment

“Allow £400 for tiles” is not a price; it is a placeholder that will become whatever the tiles cost. A quote containing three provisional sums has a total that means considerably less than a quote with none, and comparing the two totals directly is the mistake the whole system exists to prevent.

So provisional sums are pulled out and shown as a separate figure: firm price, provisional sums, and total. Two quotes at thirteen thousand where one has two hundred provisional and the other has two thousand eight hundred are not the same quote, and that is visible at a glance rather than on the fourth read.

Assumptions are price conditions

“Assumes existing pipework is sound” and “assumes clear access from the road” are conditions on the price, and they are the mechanism by which a quote becomes a different number once work starts. They belong in the comparison as their own row, phrased in the supplier’s words.

Next: what the comparison looks like.

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