1. Three reasons why lines are not comparable
They apply at the same time and reinforce one another. None of them is decisive on its own.
| Reason | Content |
|---|---|
| A different distribution of margin | lines that can be built more cheaply often carry a larger margin |
| Different content under the same name | one tenderer includes preparatory work in the line, another does not |
| A different division | without a prescribed structure the lines may not line up at all |
The third is the most common and the most easily removed, as covered by the article on a common classification. The remedy is a common classification.
2. What to compare instead
Three things are genuinely comparable, and the third is the most often left aside. It concerns the contract terms.
The total at equal content. Completeness of content, that is whether anything is missing. And the terms, that is the completion date, the guarantee, the payment schedule and liability.
The third affects the client's actual cost more than the difference in a few lines: a longer guarantee or a more flexible payment schedule may be worth more than a three per cent difference in price. Differences in terms surface only later.
3. Two useful checks
Both can be made without comparing lines, and the first is the client's strongest tool. It is requiring a schedule of works.
| Check | What it shows |
|---|---|
| Checking for missing work | whether a tender is lower because something has been left out |
| Checking the spread | where one tender is substantially lower than the others, it deserves an explanation |
The first requires a schedule of works, not prices, and this is exactly where it matters who draws up the schedule of works, as covered by the article on preparing the structure. A schedule is acceptable to tenderers.
4. When lines do become comparable
One condition changes everything, and it is the practical aim of the whole guide. The form must be set in the procurement.
If every tenderer prices the same prescribed structure and the same quantities, the lines become comparable. The difference in the distribution of margin remains, but it no longer prevents content from being compared: a difference between lines then shows pricing strategy, which is useful information in itself.
And the comparison of totals becomes reliable, because the content is demonstrably the same. The aim is therefore not to force companies to disclose more but to give them the same form.
5. What not to do
Three frequent mistakes, of which the first is the most widespread. They concern the basis of comparison.
Do not pick the lowest line from each tender and assume such a combination is available: the tenderer knows it is not realistic, and it creates mistrust. Do not press a tenderer to reduce individual lines, since that moves the margin elsewhere rather than removing it. And do not read a high line as dishonest, since it may simply be where the margin has been concentrated.
Summary and four practical rules
Lines are not comparable for three reasons at once: a different distribution of margin, different content under the same name, and a different division, of which the last is the most easily removed. What should be compared is the total at equal content, the completeness of content and the terms, the last of which affects actual cost more than the difference in a few lines. Checking for missing work is the client's strongest tool, and it requires a schedule of works, not prices.
Four rules: compare the total, the completeness of content and the terms, not the lines. Check whether anything is missing. Ask for an explanation where the spread is wide. Prescribe a common structure where comparability of lines matters.
This article offers professional orientation as at the date of verification. It replaces neither a quotation nor the assessment of a competent specialist.