Building above a frame you did not set out

Most of the work on Project Onyx happened above a line somebody else drew. The foundations were in when we were appointed and the column positions with them, so the grid, the spans and the footprint of all three buildings were settled before the first sketch.

That is a constraint, but it is a specific one, and knowing exactly what it forbids is what makes it workable. A reinforced concrete frame fixes two things: where the columns stand, and what the slab spans between them. It fixes nothing else. Blockwork in that system is infill. It carries its own weight and nothing more.

So the question on a job like this is never whether a wall can move. It is whether there is a column in it. Walls without columns went wherever a room needed to be a different size. Walls with columns stayed, and the room was made to work around them.

The failure is treating the whole inherited set as fixed because part of it is. A client who has paid for foundations will often assume the drawings above them are equally settled, and an architect who does not separate the two will quietly design as though they are. An inherited frame is a small number of hard constraints wrapped in a large number of soft ones. The job starts with sorting them.

Where it stops: what is drawn is not always what is in the ground. On a foundation already cast that gets discovered with a tape measure rather than a revision, and every room size settled above it moves with the discrepancy.