How do provisional sums hide costs in Garowe tenders?

Provisional sums underbidding risks in Garowe start with a number nobody has priced properly. A bidder writes a low allowance for work that is not yet defined, the total looks competitive, and the real cost appears later as a variation. The allowance is a placeholder, not a commitment, so comparing totals without opening each sum tells you little about the final bill.

What does a provisional sum actually cover in a Garowe bid?

It covers work the tender documents cannot yet define, such as excavation below an unknown level, connection to a service, or ground treatment if the soil needs it. The bidder prices an allowance, and the contract should say whether that sum is defined or undefined. A defined provisional sum carries a description and often a rate basis. An undefined sum is closer to a guess.

Ask each bidder for the same three things in writing: the quantity assumed, the rate or build-up behind it, and the source of both. Where the documents leave the scope open, ask the municipal engineer's office whether it holds borehole logs, service records or earlier drawings for the plot. Walk a recent site nearby with similar ground and ask what the excavation actually cost in time and plant. Those checks turn an allowance into a range you can defend at evaluation.

Why does a low allowance look like a cheaper bid?

The evaluation total adds the allowances at face value, so a small number pulls the bid down without changing the work. The bidder who writes the smallest allowance may simply have assumed the easiest ground, the shortest connection or no treatment at all. Nothing in the arithmetic shows that assumption.

Line up the allowances side by side across the bids. One bidder may allow for a shallow trench, another for rock breaking, a third for imported fill. Set out the assumed quantities and rates next to each other and the spread becomes visible. Then check the contract: who carries the cost when the allowance is exceeded, how the rate is adjusted, and what notice the contractor must give before extra work starts. General practice for undefined sums is to re-measure against agreed rates, but confirm the mechanism in your own contract, not from a rule of thumb. If the wording is silent, treat the shortfall as a live risk to the client, not to the bidder.

How do you close the gap before you award?

Normalise the allowances first, then compare. Give every bidder the same scope note and the same measured basis, and ask them to resubmit the sums on that basis. Reject bids that leave a sum blank or describe it as included elsewhere without naming where.

Where the ground or services are genuinely unknown, buy the information before the tender closes. A trial pit, a service trace or a short borehole can cost less than the argument that follows an undefined sum. Ask the laboratory or driller for their rate in writing and put the records in the tender pack so every bidder prices the same ground. For sums that stay undefined, hold a contingency the client controls and record how it will be released. Then rank bids on the corrected totals and note the allowance risk beside each one.

What to do next

Pick the two lowest bids and list every provisional sum in both. For each one, write the assumed quantity, the rate basis and the evidence behind it, then ask each bidder to confirm or correct it in writing. Send the same list to the others if the scope note changes, and re-rank on the corrected totals before you sign.