Variations
Who on site is actually allowed to instruct extra work?
Half the people on a building site sound like they are giving instructions. Under your contract, usually exactly one of them is. Work ordered by anyone else is work you may not get paid for, however senior they sounded by the scaffold.
QScope Team·8 December 2025·4 min read
The clerk of works wants the DPC detail changed. The client’s partner would like the doorway wider while the wall is open. The structural engineer mentions a bigger padstone. All real, all reasonable, and possibly none of them an instruction.
The contract names one person
On a job with a contract administrator or architect, the contract empowers that named role to instruct, and instructions from that person bind the client, including on cost. That is the whole design of the arrangement: one channel, so the client is not committed by every conversation on site.
Which means the engineer, the clerk of works, the interior designer, the tenant and the client’s family can request, suggest and require, but not instruct. Some of them can reject work as non-compliant; that is a different power from ordering new work. If you build what they asked for and the contract administrator never adopted it, you did it as a volunteer.
What about the client themselves?
On a job with a contract administrator, even the client’s own site-visit wishes usually need to go through the named channel, and the polite fix is the same email as below. On a job without one, typically the domestic extension, the client is the other party to the contract and their word is the instruction. There the problem is not authority but evidence, which is the territory of confirming what was said on site.
The one-line email that fixes it
When the wrong person orders something real, do not refuse and do not just build it. Route it:
“On site today [engineer] asked us to increase the padstone at gridline B. We are happy to do it and expect a cost effect. Please confirm your instruction.”
Sent to the contract administrator, that converts a corridor conversation into an instruction, or flushes out early that the client will not pay for it, while the wall is still open and the choice still exists. This is practice, not law, and it costs one minute.
What to do this week
1. Write down who holds the instruction power on each live job. One name per job. If you cannot name them, that is the first gap to fix.
2. For anything built recently on the say-so of someone else, send the routing email now, honestly dated, while the goodwill is warm.
3. Brief your own people: site staff take requests from anyone, but nothing gets built as extra until the named person has confirmed. Then price it through the ladder.