Variation Order

A client asks a contractor to move a wall after construction begins, and the original drawings and price did not allow for that work. A variation process records the change and determines how cost and schedule are handled, so the parties do not rely on different versions of the project scope.

An Asian Development Bank training presentation explains FIDIC Red Book variation procedures and Ramskill Martin discusses changes under JCT contracts, but these standard forms use different roles and steps, so a project should follow its signed contract rather than assume every "variation order" has the same form or effect. A change may arise from the client, engineer, design team or an unforeseen site condition, and the contract determines who can instruct it.

A site employee's request may be operationally sensible but outside that person's authority, so check the instruction route before committing material cost. Describe the change precisely by identifying drawings, specification revisions, quantities and affected work, because "upgrade lobby" is too vague to price or build, while a numbered variation tied to the contract helps site, procurement and finance teams work from one scope.

The contractor may be asked to provide a proposal with price and time effects before an instruction is issued, while some contracts permit an instruction first and valuation later. The distinction matters if urgent work cannot wait, so document assumptions and keep contemporaneous records rather than reconstructing cost months afterward.

Price can use contract rates, agreed quotations or valuation rules, and a contractor may add labour, materials, plant and permitted overhead according to the contract. Do not assume every extra cost is recoverable at invoice value, and an omission may reduce the contract price but have other consequences under the terms.

Time should be assessed separately from cost, since a small change can affect critical-path work and delay completion while a costly material substitution might not, and a price agreement alone may not grant an extension of time. Notice provisions can be strict, so a contractor may need to notify the client or engineer within a period after an instruction or event, and missing a required notice can affect entitlement depending on contract and law; set a workflow so project managers and quantity surveyors see changes immediately.

A variation can affect subcontractors, for example where a ceiling specification change needs aligned quotes and schedule updates from electricians or installers, and the main contractor's subcontract rights may differ from its obligation to the client, so review downstream contracts before promising a fixed amount. Approval should be traceable, so store the request, proposal, authorised instruction, pricing basis and final decision, and label any provisional price as provisional rather than treating a spreadsheet estimate as an approved payment certificate.

Consider an illustrative $20 million contract with an authorised $500,000 addition and a $100,000 omission: the arithmetic net change is $400,000 before other adjustments, but only if both items are validly valued and agreed, and it says nothing about extra time or tax. Keep a current change register showing each item as proposed, instructed, priced, agreed, disputed or paid, with an owner and due date, which helps prevent scope creep from hiding in site emails and gives finance a more reliable forecast of final project cost.

Disputes can arise over whether work was a change at all, such as when a contractor says a drawing revision added scope and the client says it merely clarified the original design, so compare original contract documents and instruction history and avoid assuming every site difficulty is compensable. A variation order is a controlled way to change the project, not a guarantee of a particular price or date, so identify authorised instructions, evaluate both cost and programme, and keep the evidence.