Why do subcontractor quotes come in low in Borama?

A low subcontractor quote in Borama rarely means the bidder works cheaper. It usually means the bidder priced a narrower scope than your drawings show. The subcontractor quotes underbidding risks come down to what sits outside the priced lines: preparatory work, testing, temporary works and the interface where one trade hands over to the next.

How does a low subcontractor quote in Borama happen?

A bidder wins work by pricing the visible product and dropping the steps that produce it. On a block wall, that can mean the rate covers laying blocks but not setting out, scaffolding or curing. On foundations, it can mean the excavation line exists but the compaction and testing lines do not. None of this is dishonest on its face; each bidder simply reads the scope differently under time pressure.

The mechanism is asymmetric information. The bidder who understands the site best can price the risk he sees; the bidder who prices lowest often has not looked. Ask each bidder to return your bill of quantities with every line priced or explicitly marked nil, and to state in writing what he assumes the client provides, such as water, power, access or storage. Check the difference between nil and omitted lines. A nil line means the bidder accepts no cost, which is a claim you can test. An omitted line means the bidder never read the item.

What interface work goes unpriced between subcontractor packages?

Interface work is the work at the edge of two packages, and both bidders can assume the other carries it. Typical gaps include preparing and cleaning a substrate before the next trade starts, forming and closing openings, sealing a joint between two materials, and leaving fixings or starters for a following trade.

Blockwork normally precedes plaster, and plaster normally precedes tiling, with each trade needing a surface the previous one left in a fit state. Confirm the actual sequence against the project programme and specification, because wet-trade drying times, backing type and programme changes can move it. If the blockwork quote excludes raking out joints and the plaster quote excludes preparation, nobody owns the step and the work stops until someone agrees a variation. Detect this before award by writing a one-page scope schedule that lists every handover point in the build and naming the package responsible for each one. Hold a short meeting with the two bidders whose scopes touch and ask each to confirm in writing where his work ends. Price the interface lines yourself and add them as a provisional sum so the money is visible from the start.

How do you compare low quotes on one basis?

Put every quote onto one scope schedule, one bill of quantities and one set of units. A quote priced per square metre of wall and a quote priced per block cannot be compared until you convert both to the same unit and the same inclusions.

Build a comparison sheet with one column per bidder and one row per scope item, then mark each cell as priced, nil or absent. Absent cells are your first question list. Ask each bidder to price the missing items on a formal addendum, in writing, before you evaluate. For items a bidder still cannot or will not price, standard practice is to carry the highest received rate for that item against every bidder, or to add a stated allowance the client bears; say in the evaluation which approach you are using and apply it to all bidders the same way. That keeps the comparable total honest without accusing anyone. Also ask for the method statement and programme behind the price. A quote that names its curing method, its temporary works and its testing plan has been thought through; one that names only materials has not.

What to do next

Collect the lowest quotes you have received and one blank scope schedule. Walk a comparable site and list every handover point you see, from substrate preparation to joint sealing. Mark each quote against that list and send the resulting question sheet to each bidder for a written response before you award anything.

Confirm testing, inspection and permit requirements with the municipal engineer's office, and check what your contract allows before you adjust any payment or retention.