Across every service · Technical escalation

When does a passive fire variation need technical or engineering review?

What changes the answer

• Whether the change sits inside the tested range or outside it. Inside is a records exercise; outside is a technical one.
• Which part changes — substrate, service, opening size, component, orientation, or the detail itself. Each has a different route to an answer.
• Whether the system holder will support it by assessment, and how long that takes. That lead time belongs in the programme, not in a surprise at handover.
• Whether a fire engineering report already governs the area, in which case the engineer is in the conversation from the start.
• Whether it is already installed, which turns the question from what to do into what to do about it.
• How many times the same variation occurs on the job. One assessment covering fifty instances is a very different cost from fifty conversations.

What to check on site

• The original tested detail and its stated limits, not the one-page summary sheet.
• What specifically differs, measured rather than described.
• Whether the substitution stays within one system or jumps between two. A component from another system is a new system.
• The orientation. A wall test does not carry to a floor, and the evidence usually says so plainly.
• Whether the variation changes anything beyond the seal — a bigger opening can change the support and the surrounding construction as well.

What to do next

Send the original detail, the proposed change and photographs of the condition it has to suit. We will tell you which of the three routes it takes, what evidence would be needed, and who has to produce it — before it becomes a cost argument at handover.