2 min read
The drawings changed on site
"The drawings changed on site" is one of the most expensive sentences in construction when nothing is written down. Here's why, and what to do instead.
Every site manager has said some version of this sentence. The architect's drawing shows one thing, the reality of the building shows another, and a decision gets made on the spot to keep the job moving. Nine times out of ten it's the right call. The problem isn't the decision, it's that nobody wrote down what changed, why, or who agreed to it.
Six months later, when a snag turns up, or a client questions why a room is a different shape to the plan they were shown, or building control asks why the finished structure doesn't match the approved drawings, "the drawings changed on site" is not an answer anyone accepts. It sounds like an excuse because, without a record, that's all it is. Nobody can say who made the call, what the reasoning was, or whether the client was ever told.
In practice, most on-site changes are sensible responses to something the drawings couldn't have anticipated, an unexpected service run, ground conditions, an existing wall that isn't where the survey said it was. The problem is purely evidential. A photo of the issue, a note of the change, and who signed it off takes two minutes and turns a defensible decision into a documented one.
This matters most for anything structural or related to building regulations. If a change affects fire escape routes, structural loading, drainage falls, or insulation continuity, an undocumented on-site change can become a compliance problem that surfaces at completion, at sale, or worse, after occupation. Building control inspectors expect deviations from approved drawings to be recorded, not discovered.
The habit that fixes this is small: whenever a decision is made that departs from the drawings, someone takes a photo, writes a sentence explaining what changed and why, and logs it against that stage of the job. It doesn't need to be a formal design change notice for most residential and small commercial work. It needs to exist somewhere other than in the site manager's memory, which is exactly what a proper site diary and photo log are for.