Deviation vs Change: What is the difference?

Why does it matter?

In construction law, wording is important. Depending on whether something is classified as a deviation or a change, the process for approval and compensation looks different. For you in the field, it's about being clear so the client understands why the cost or schedule is changing.

Although the examples here come from the construction industry, the same principles apply to service companies, cleaning firms, electrical, plumbing, ground works, assembly, and other recurring site work where time, deviations, and extra work must be proven.

What is a deviation?

A deviation is something that happens outside your control. It involves a discrepancy between how it should be according to the documents and how it actually is on site.

• Example: You find rock where there should be soft soil according to the drawing.
• Example: Another contractor has not cleaned up after themselves, which hinders your work.
• Handling: You must report the deviation immediately (notify) to be entitled to time extension or extra compensation.

What is a change?

A change is an active choice by the client. It is about wanting to do something different than what was originally decided.

• Example: The client chooses a more expensive fixture than what was in the estimate.
• Example: They decide to repaint a wall that has just been finished with a new color.
• Handling: Often requires a written order (Change Order) before the work begins.

Handle both without conflict

The key to a good relationship with the client is proactivity. By documenting both deviations and changes continuously in the daily report, you create a shared picture of reality.