How do you spot underbidding in demolition sequencing in Berbera?

A low demolition bid breaks down at the items the bidder left out, not at the labour rate. Demolition sequencing underbidding risks are highest when a tender prices the visible structure and ignores the temporary works that hold it, the survey that confirms it, and the transport that clears it. None of those omissions appear in the total on the bid form.

Why does the low bid hide more than price?

A demolition quote carries several cost groups: the survey, the sequence, the temporary works, the machines, the labour, the debris removal and the reinstatement. An underbidder often prices only the machines and labour. Omitted items can include the structural survey, propping and shoring, dust and noise control, and debris cartage to a licensed tip.

One mechanism drives the whole gap. The bidder assumes the structure behaves as the drawings show, so it needs no temporary support, then prices accordingly. Where a wall, slab or foundation turns out to be thicker, tied into a neighbouring structure or partly collapsed, the sequence changes and the cost lands on the client as a variation.

Check the priced scope line by line against the tender drawings. Ask the bidder to name the rate it used for debris removal and where the material will go, and to state what method it intends for each element. A bid that leaves those blank is not cheap; it is incomplete.

What does unexpected structural instability do to the programme?

When a structure behaves differently from the assumption, the work stops and the sequence is rewritten. Demolition relies on a planned order: strip finishes, remove secondary elements, then take the primary frame down in a controlled direction. If an element that was assumed stable moves, or a shared wall turns out to carry a neighbour's load, the supervisor must halt, prop and redesign the sequence before anyone re-enters.

This is where the underbid becomes visible. The contractor either stops and asks for more money, or proceeds with the original method and accepts the risk. The second path produces unauthorised methods, unsafe access and debris in the wrong place.

General practice for partial demolition is to prop and shore before cutting, keep the site clear of the intended fall zone, and prevent debris from loading a floor that was not designed for it. Treat those as general guidance and confirm the actual sequence, prop spacing and load limits against the project's specification and a qualified engineer.

To read the local ground and structure, ask whether any record drawings or previous demolition permits exist for the plot. Then walk a recent demolition site nearby and look at how it propped, where it stockpiled debris and how it controlled access.

How do you close the gap before award?

Close it in the tender, not on site. Require a priced schedule of temporary works, a method statement with the demolition sequence, a debris disposal route and a named responsible engineer. Ask each bidder to list its assumptions about the existing structure, then check those assumptions against the survey.

Set the payment structure so the omitted items cannot be skipped. If the contract allows, tie progress payments to completed sequence stages and to the removal of debris from site, not to time on site. Check what the contract says about variations, suspension and who carries the cost of a changed method before you sign, and take advice on the wording.

For the site, ask the municipal engineer's office which permits and notifications apply, what hours are allowed and where debris may be tipped. A bid that cannot answer those questions has not priced the job.

What to do next

Open the tender documents and mark every item the lowest bidder left out: survey, propping, dust control, disposal and reinstatement. Then send one written question to that bidder and to one other, asking each to price those items separately and to name its structural assumptions. Compare the answers before you award.