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Variation approvals: how builders get paid for extras

By The Buildflow teamPublished 6 min read

Unwritten extras are where residential margin quietly disappears. A variation you cannot evidence is a variation you will end up absorbing at final account.

Every residential job changes. The client moves a door, the ground opens up worse than expected, the specification for the kitchen doubles. None of that is a problem — the problem is agreeing it verbally on site and pricing it afterwards. By then the work is done, the goodwill is spent, and the conversation is about whether you ever mentioned a cost at all.

1. Define what counts as a variation before you start

Set the rule in the quotation: anything outside the written scope, including client-instructed changes and unforeseen ground or structural conditions, is a variation priced separately. When the definition is agreed at contract stage, raising one later is administration rather than confrontation.

2. Price cost and time together

A variation has two impacts and clients only ever hear the first. State the additional cost and the additional programme days in the same document. Extensions of time agreed at the point of change prevent a delay argument later.

3. Get approval in writing before the work happens

Written means dated and attributable: an approval recorded against the specific variation, by a named person, at a known time. A client portal or CRM record does this better than email because the approval sits next to the priced scope rather than three replies below it.

4. Number them and keep a running total

VO-01, VO-02, and a live figure for approved variations against the original contract sum. Clients handle incremental costs far better when they can see the running total than when it lands as one number at the end.

5. Reflect approved variations in the payment schedule

An approved variation that never reaches an application for payment is a gift. Push it into the payment schedule automatically the moment it is approved, so valuation and final account already agree.

6. Keep the paper trail for the defects period

Twelve months later, the question is often whether something was in scope. Approved variations, with their dated sign-off and photographs, answer it in seconds and keep a defects conversation from turning into a dispute.

What every variation record should contain

  • A unique number and a plain description of the change
  • Who instructed it and when
  • Cost breakdown: labour, materials, plant, margin
  • Programme impact in days
  • Dated client approval before work starts
  • Photographs of the affected area, before and after
  • A link to the updated payment schedule line

Frequently asked questions

What is a variation in a construction contract?

A variation is any authorised change to the scope, quality, quantity or programme of the works after the contract is agreed — a client-instructed change, a design development, or an unforeseen condition. Under JCT contracts variations are valued and can carry an extension of time.

Can a builder charge for a variation without written approval?

Recovery is possible but far harder. Without dated written approval you are relying on witness recollection and conduct, and residential clients frequently dispute it. Written approval before the work happens is the only reliable position.

Who approves variations on a residential project?

Usually the client or their appointed contract administrator or architect. Record which of them holds authority at contract stage, so approvals are not later challenged as having come from the wrong person.

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