How do design queries hide risk in a Qardho low bid?

A low bid on a Qardho building often means the bidder priced the drawings exactly as issued and ignored every design query the drawings raise. If those queries are left unanswered, they can return during construction as claims or substituted details. Underbidding driven by unresolved design queries is a documentation problem before it is a money problem.

What does an unresolved design query do to a low bid?

An unanswered query lets each bidder guess, and the lowest bidder usually guesses cheapest. A drawing may show a foundation depth without a note on the founding stratum, or a roof detail without a fixing specification. A bidder may price a conservative, buildable detail while another may omit the item and expect a later clarification. When the tender is compared line by line, the second total looks lower even though the scope is identical. That is not a pricing trick, it is an information gap doing the work. Ask whether the relevant authority holds any site or servicing records for the plot, and require every bidder to price against the same written answers. A bid clarification register, kept with the tender documents, is the basic tool. It records the question, the answer issued, and the date, so comparison happens on equal scope.

How do unresolved site instructions turn into claims?

An instruction given on site but never written up becomes a claim argument later. Confirm the supervision and site arrangements with the project's engineer. A verbal direction to shift a wall, deepen a trench or change a pipe route can be absorbed into the work and then disputed at the next valuation. The contractor says the work was extra. The client says the original drawings covered it. Nobody has a signed instruction. General practice in construction is that every instruction is issued in writing, numbered, and acknowledged before the work starts, but confirm the format with the project's engineer and check what the contract allows for variations. A daily site diary that records who gave what instruction, and to whom, closes most of this gap. Walk a recent site with the supervisor and ask whether an instruction log is kept.

How do you spot unrealistic tender allowances before award?

Look for rates that cannot cover the work, not for a low total. Check whether the preliminaries, testing and contingency lines carry enough to cover the work described in the issued documents. Check each bidder's assumptions against the issued documents: how many site visits, what water source, what curing method, what supervision. Ask two suppliers for written quotes on the main materials and compare the bidder's rates to those, not to each other. If a rate sits below every quote you hold, ask the bidder to explain the method, not to raise the price. Confirm the local rates yourself rather than relying on any figure quoted in conversation. Ask each bidder to explain the method, the crew and the sequence in writing, then judge that answer against the documents.

What to do next

Before you award, reissue the drawings with a numbered query log attached, and ask every bidder to confirm in writing that their price covers the answers issued. Then set one rule for the site: no instruction, no work. Keep the log on site and review it at each valuation. That single habit turns most future claims into settled questions.