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Estimate documents

Variations, change orders, and daywork.

Variations and change orders are how construction contracts handle changes to the original scope. Daywork provides a mechanism for pricing work that cannot be measured in advance.

Who this guide is for

Contractors dealing with client-requested changes, project managers documenting variations, and anyone who needs to ensure additional work is properly authorised and paid for.

Key documents

Variation: A change to the original contract works, whether an addition, omission, or substitution. Must be instructed in writing.
Change order: The formal document authorising the variation, including cost and programme impact.
Daywork: Used when the scope cannot be pre-measured. Labour, materials, and plant are charged at agreed rates with supporting timesheets.

Miniature example

During a bathroom refurbishment, the client asks for the wall to be moved by 300 mm. This is a variation. The contractor issues a change order: additional £450 for wall alteration, extra 1.5 days. If the client asks for unplanned exploratory openings to check pipework, this is measured as daywork at pre-agreed rates.

Common mistakes

• Starting work on a verbal instruction without written confirmation
• Not tracking daywork hours and materials daily — reconstructing weeks later is unreliable
• Failing to notify the client of cost and programme implications before proceeding