Before you argue about the number, it helps to understand what you actually agreed, where the real risk sits, and what you need to know before you decide anything.

What a lump-sum contract means

A lump-sum contract is a single price for a defined job. The contractor quotes it, you accept it, and the risk of getting the estimate wrong sits with the person who made the estimate. If he underquoted, that is, in principle, his loss to carry. That is the whole point of a fixed price: you pay more for certainty.

So when a contractor asks for fresh rates halfway through, what he's really asking is to turn a fixed-price contract into a measured one, and move his estimating mistake onto you.

On paper, the owner is usually in the stronger position. In practice, it depends on who is holding the money.

The real risk: paying ahead of the work

Many residential contracts in Pakistan front-load the payments. By the time the dispute starts, the owner has often paid well beyond the value of the work on site.

Take a simple example. A Rs 2 crore grey-structure contract, 60% complete, with Rs 1.7 crore already paid. The work on site is worth about Rs 1.2 crore at contract terms. The contractor is holding around Rs 50 lakh of the owner's money for work that hasn't been done, and only Rs 30 lakh is left to earn for the remaining 40% of the job.

That is why "just hold him to the contract" often fails. With little left to earn, the contractor has little reason to come back, and a plain contract with no termination or penalty clauses is slow to enforce.

Is he telling the truth?

Sometimes, yes. Steel and cement prices move, and an honest contractor can genuinely underestimate. Sometimes the low quote was the strategy: win the job cheap, take the early payments, renegotiate once the owner is committed. Usually it's somewhere in between.

You can't tell which from the conversation. You can only tell from measured facts.

The two numbers you need before deciding

  1. What the completed work is worth under your contract. Measure what has been built, value it against the agreed price, and compare that with what you've paid. This tells you exactly how far ahead or behind the payments are.
  2. What it would cost to finish at today's rates. Quantify the remaining work and price it at current Lahore material and labour rates. This tells you what walking away actually costs.

Keep the two separate. The first shows where you stand under the agreement. The second shows the market reality. Mixing them is how owners end up paying a "revised rate" for work they had already paid for.

Your realistic options

  • Hold him to the contract, with no further payments until the measured work catches up with the money paid.
  • Agree a limited, written top-up, but only if the numbers show that finishing with him is still cheaper than switching, and only tied to measured progress.
  • End the contract and recover the overpayment, using the measured valuation as the basis, then complete with a new contractor on a properly written agreement.

None of these is right in every case. A fair top-up can be the cheapest outcome; a stubborn stand-off can be the most expensive.

What to do this week

  • Don't sign new rates or pay anything extra under pressure.
  • Collect your documents: the contract, drawings, every payment record, and any bills or messages from the contractor.
  • Photograph the site as it stands today, before anything changes.
  • Get the work measured independently, ideally by someone both you and the contractor agree to accept. If he is the one asking for an audit, that agreement is easier than you think.
  • For enforcing or ending the contract, speak to a lawyer. A measured report is the evidence they will need.

Most of these disputes don't turn on who is right. They turn on who has the facts. Get the facts first, then decide.