Tender Document Errors That Make Bids Impossible to Compare

Most failed tender evaluations were lost at the drafting stage. These are the document errors that leave you comparing six prices for six different scopes.

When bids arrive spread across a wide range, the instinct is to suspect the bidders. More often the documents allowed each bidder to read the scope differently, so the range measures ambiguity rather than competitiveness. Every error below is introduced before the tender is issued, and every one is cheap to fix at that point and expensive to fix later.

Why these keep happening

Tender documents are usually assembled under time pressure from several sources: drawings from the designer, a specification from a previous job, a pricing document from the cost adviser and conditions from a lawyer. Nobody is tasked with reading the whole pack as a bidder would. The result is a set of documents that each make sense alone and contradict each other in combination, and bidders resolve the contradictions in whichever direction suits their price. The fix is one person, one uninterrupted read, with authority to hold the issue until the conflicts are closed.

1. No stated method of measurement

A bill item saying blockwork measured in square metres does not say whether openings are deducted, whether returns are included or how the item relates to the specification. Without a named method of measurement, two estimators can price the same item honestly and differently, and neither is wrong.

• Avoid it by: Name the method of measurement in the preliminaries and state which edition applies, then make sure the bill was actually prepared on that basis.
• Proof it is closed: A bidder query asking which method applies receives a one line answer that points to the document rather than prompting a discussion.

What it costs you: Bids that differ by more than the real market spread, and a valuation argument every month once work starts.

2. Drawings and specification that disagree

A drawing shows one glazing system and the specification describes another, or a finishes schedule lists a material the drawing never shows. Bidders price the cheaper interpretation because that is how they win work, and the difference becomes a variation claim at the first site meeting.

• Avoid it by: Run a documented cross check between drawings, schedules and specification before issue, and state an order of precedence in the conditions for anything missed.
• Proof it is closed: A completed coordination checklist signed by the designer, plus a precedence clause that a bidder can apply without asking you.

What it costs you: A variation on an item you believed was included, priced without competitive pressure.

3. Provisional sums with no definition

A lump allowance labelled as a provisional sum for external works tells the bidder nothing about what it must plan, programme or price around. Undefined allowances are excluded from the contractor programme, so when they are instructed they arrive as both cost and delay.

• Avoid it by: Define each provisional sum with a description, an indicative quantity and a statement of whether the contractor must programme for it.
• Proof it is closed: Every provisional sum in the bill has a paragraph in the preliminaries explaining what it covers and how it will be instructed.

What it costs you: Programme disruption on top of the expenditure, because the work was never in the plan.

4. Site information supplied without status

A ground report, a survey or an asbestos register handed to bidders with no statement of its contractual status leaves everyone guessing whether they may rely on it. Some bidders will price a contingency for unreliable information and some will not, and your comparison is ruined.

• Avoid it by: State clearly which documents are provided for information only and which the contractor may rely on, and keep that statement consistent with the risk allocation you chose.
• Proof it is closed: A schedule of site information with a reliance status against each item, referenced in the conditions.

What it costs you: Either an inflated price for risk you already understood, or a claim when conditions differ from the report.

5. Preliminaries that do not describe the actual site

Standard preliminaries copied from an earlier project will describe access, working hours, laydown space and welfare that have nothing to do with your site. A city centre plot with a single narrow access and restricted delivery hours is a completely different job from a greenfield plot, and the preliminaries are where that is priced.

• Avoid it by: Write the preliminaries from a site visit and name the constraints explicitly, including deliveries, noise limits, neighbour obligations and any permit you will not obtain.
• Proof it is closed: A bidder who has visited the site cannot find a constraint that the preliminaries failed to mention.

What it costs you: A claim for restricted working, or a bidder who prices the restriction generously because the documents left it unclear.

6. No pricing structure for change

If the documents do not require bidders to submit rates for labour, plant and common materials, you have no basis for valuing work that falls outside the bill. Every subsequent variation is then negotiated from the contractor quotation with no benchmark.

• Avoid it by: Require a schedule of labour and plant rates, percentage additions for overhead and profit, and a daywork basis as part of the tender return.
• Proof it is closed: The signed contract contains rates that can be applied to a hypothetical variation without further negotiation.

What it costs you: Variation pricing consistently at the top of the reasonable range, for the life of the project.

7. A return format that invites qualifications

If the tender does not say exactly what to submit and in what form, bidders attach their own clarifications, assumptions and exclusions. Each one is a quiet amendment to the scope, and comparing six differently qualified bids is a guessing exercise.

• Avoid it by: Issue a fixed return format with a single schedule for qualifications, and state that anything outside it will be disregarded.
• Proof it is closed: Every bid arrives in the same structure and all departures from the documents are listed in one place.

What it costs you: Weeks of normalisation and the real risk of awarding to the bidder with the cleverest exclusions.

A short check before you sign

• One named person has read the entire tender pack end to end as a bidder would.
• The method of measurement, the order of precedence and the status of site information are each stated once and are consistent.
• Every provisional sum has a definition and a programming instruction.
• The tender return format requires rates for valuing change and a single qualifications schedule.
• Preliminaries have been rewritten from an actual visit to this site.
• All queries raised during the tender period were answered by formal addendum to every bidder.

If it has already happened

If bids are already in and incomparable, do not try to fix it in a spreadsheet. Identify the three or four items driving the spread, issue a short addendum that defines them properly, and ask every bidder to resubmit only those items on a stated basis. That costs a fortnight and preserves competitive tension. Awarding to the lowest number and resolving the ambiguity afterwards moves the same money into variations, where you have no leverage at all, and the procedural rules that govern public and funded tenders change from time to time, so confirm what a re tender requires before you act.

Domira builds and supervises projects across Saudi Arabia, and the commercial discipline above is how its projects stay inside their budget and their programme. Send the drawings, the contract or the site and Domira will tell you where the risk actually sits.