Construction variation software holds work that was not in the contract as awarded and the process by which it becomes payable. It carries extra items and quantity deviations, how each was priced and on what basis, the approval chain and where each proposal currently sits, confirmations issued against verbal instructions received at site, the time impact alongside the cost impact, and the running total of work executed without approval in place. With Pentoggle, a contractor can describe its variation types, sanction chain and rate basis and generate the starting application around them.
Variations arrive in several forms. An item with no equivalent in the awarded bill. An item executed beyond the quantity awarded. A specification substituted for another. Work omitted by the client. Each is priced differently and each follows a different approval route, and contract terms on deviation limits, rate basis and sanction authority vary considerably by client and by department, so build around what your contracts actually specify.
Many contractors already run Tally or a comparable accounting system and maintain variation correspondence in email. What is usually missing is a single list of what has been claimed, what has been approved, and what has been built on nothing but a conversation.
Key takeaways
- Work instructed verbally and executed without written confirmation is a well known way for contractors to lose recoverable value on variations.
- A variation approved for cost but silent on time can leave you liable for a delay you were instructed to cause.
- The basis on which an extra item is priced usually matters more than the arithmetic, and it should be agreed before the work rather than after.
- Approval obtained after the work is built is a different negotiation, because the leverage has gone.
- A useful number is the value of work executed without approval in place, aged from the date of execution.
What the variation file does well, and where it stops
Many contractors handle this through correspondence. A letter proposing an extra item, a rate analysis attached, follow up emails, minutes recording a discussion, and eventually a sanction. The commercial team knows the position on the significant ones and can find the paper.
It stops working in three specific ways.
Small items disappear
A project generates a large number of minor variations, each individually not worth a letter, and collectively worth a great deal. They get done, they get mentioned, and many are never formally raised at all.
The status of each is unknowable in aggregate
Which proposals are with the consultant, which are with the client, which were rejected and never revised, which were approved and never billed. Each answer is in a different email thread, so the total is nobody's.
Verbal instructions leave no trace
The most consequential category is also the one with no document by definition, unless somebody creates one immediately.
What variation software holds
The variation register
Each proposed variation with its type, description, value, current status and where it sits.
Rate derivation with basis
How the rate was arrived at, whether from an analogous contract item, from first principles, from a schedule of rates or from quotations, with the working retained.
The approval chain
Who the proposal is with, since when, and the sanction level required, since larger values often need higher authority.
Verbal instruction and contemporaneous confirmation
Instructions received at site recorded the same day, with who gave them, what was instructed and where, plus the written confirmation or notice issued and its response status.
Time impact alongside cost
Whether the variation extends any activity or the completion date, recorded with the cost proposal rather than separately.
Executed against approved
What has actually been built, against what has been sanctioned, with proposed, submitted, approved, executed and billed values visible separately.
Quantity deviation against awarded
Items running beyond their awarded quantity, feeding from measurement so overruns surface during execution.
Notice and response deadlines
Contractual notice requirements, submission dates, response due dates and escalation status, where the contract specifies them.
The link into billing
Approved variations carried into the abstract so they are actually billed, which is a step more variations fail at than anyone expects.
The verbal instruction is where the money is lost
This is the single most useful thing on this page and it is not really about software.
An engineer for the client or the consultant tells your site team to do something. Move a wall. Change a fixing detail. Break out and redo an area. Add a drain. The instruction is reasonable, the site team is cooperative, and the work gets done that week. Nothing is written down, because at the moment of the conversation nobody is thinking about payment.
Months later the bill includes it. The engineer who gave the instruction has been transferred, or remembers it differently, or was never authorised to instruct a variation in the first place. The contractor is left asserting that a conversation happened, which is not a commercial position.
A useful protective step is to issue a written confirmation promptly, recording that an instruction was received, from whom, what was instructed, where and when, and requesting confirmation or correction. This is one of the items the project correspondence record exists to carry. Whether that confirmation is sufficient for entitlement depends on the contract, the authority of the person giving the instruction and any notice or approval requirements that apply, so the specific requirements are for your contracts team to confirm.
The commercial logic holds regardless. A contemporaneous document sent the same day creates a much stronger record of what was communicated than a recollection produced during a final account. Whether it establishes entitlement depends on the contract and the response, authority and subsequent conduct of the parties.
It is difficult to do consistently because it requires someone at site to document the instruction on the day it is least convenient. Reduce that to a form on a phone, filled in three minutes, producing the confirmation ready to issue, and the practice becomes possible. It is one of the clearest cases in construction where a very small piece of software changes a commercial outcome, because the barrier was never understanding and always effort.
Approval after execution is a different conversation
Where the contract requires prior approval, the safer sequence is proposal, rate agreement, approval, execution. The sequence that actually happens is frequently execution first, because site cannot wait and the work is blocking something.
The difference is not procedural. It is a change in negotiating position.
Before execution, the client is deciding whether to have the work done at your price. They can accept, negotiate, or decide not to proceed. You are selling something.
After execution, the work exists. The client is deciding what to pay for something they already have. Arguments about difficulty or cost basis become abstract, because the evidence that it could be done is standing in front of everybody. And if the item was never sanctioned by someone with authority, there may be no obligation at all, depending on the contract.
The measurement guide covers catching quantity overruns while work is in progress, which is the upstream half of this. The variation side of it is making the proposal, the rate and the approval fast enough that site is not forced to choose between waiting and proceeding unsanctioned. Where a proposal can be raised from site the same day, priced by the commercial team the next, and tracked visibly with the client, the gap that produces unapproved execution narrows considerably.
Where work has to proceed before formal sanction, which can happen when site conditions or sequencing do not allow work to wait, the requirement is that it is recorded as such. Executed without approval, with a value and a date, sitting in a register somebody reviews. That is a manageable exposure. The same work sitting in nobody's list is a surprise at final account.
A variation approved for cost but silent on time is half approved
This one catches experienced contractors.
A variation is proposed, priced, negotiated and sanctioned. Everybody is satisfied. Nothing in the sanction says anything about the completion date, because the discussion was about money.
The work then takes time. It may sit on the critical path, or occupy a crew that was needed elsewhere, or require a sequence change that pushes several activities. The project finishes late. At that point the contractor may face a time-related exposure unless the contract provides an entitlement to additional time and the required notice and substantiation have been given.
The correction is to treat time as part of the proposal rather than as a separate claim raised later. A variation proposal that carries an assessment of its programme impact, even where the assessment is that there is none, means the question was asked and answered at the time both parties were still cooperative. Whether an extension of time follows, and what the contract requires to obtain one, is a matter for your contracts team, but the practice of assessing impact at proposal stage costs nothing and preserves the position.
The register should therefore hold cost approved and time approved as separate fields, because a variation with the first and not the second is a known exposure rather than a closed item.
Where variations look different by business type
- General Contractor Software, where a variation from the client frequently has to be passed down to a subcontractor, and the two approvals rarely move at the same speed.
- Interior Fit-Out Contractor Software, where client driven changes are constant and often verbal, and the programme is short enough that waiting for sanction is rarely an option.
- Infrastructure and Road Contractor Software, where deviations and extra items follow departmental sanction hierarchies with defined authority limits.
- MEP Contractor Software, where variations often originate in coordination changes made by other trades.
- Home Builder Software, where the person instructing changes is the owner and the relationship makes formality awkward.
Why contractors choose Pentoggle for variations
Verbal instructions confirmed the same day
A form on a phone at site producing a written confirmation, which is where most variation value is protected or lost.
One register, every status
Proposed, priced, submitted, approved, rejected, executed and billed, all in one list rather than across email threads.
Rate basis retained
How each rate was derived, kept with the proposal, so the position holds when the reviewer changes.
Cost and time held separately
Because a variation sanctioned for money alone is an open exposure.
Approved variations reach the bill
Carried into the abstract rather than approved and then forgotten.
A useful number for managing variations
Value of work executed without approval in place, aged from the date of execution.
Read it alongside a second figure: the value of submitted variations awaiting approval, aged from submission. The two describe different risks. Work executed without approval is commercial exposure you are already carrying. Submitted work awaiting approval is an approval bottleneck sitting with somebody else.
The first is exposure rather than performance. It is money the business has already spent, on work that exists, with no sanctioned basis for recovering it, and it grows quietly because every individual item felt necessary at the time.
Review it weekly and drive it down rather than admiring it. Items aged beyond a few weeks are the ones to worry about, since the people who instructed the work are still available and still remember it in the early period, and increasingly not thereafter.
A rising number is not necessarily a discipline failure. It often means the approval process is too slow for the site to work within, which is a different problem with a different fix. Treating it as a site indiscipline issue when the actual cause is a consultant taking five weeks to price a proposal will make the number worse rather than better.
Ready to build variation software?
Everything you built on a conversation is worth exactly what the other person remembers.