Journal · Drawing · 6 min read
What a section is for, and why we draw it first
A plan tells you where the walls are. A section tells you whether the building works. Most arguments on a job are section arguments wearing a plan's clothes.
A client asked us last year why every meeting seemed to end up looking at the same drawing. It is a fair question. We had brought plans, elevations, a cost plan and a programme, and by twenty minutes in all five of us were leaning over one section at 1:50.
The answer is that a plan is a drawing of a decision that has already been made. A section is the drawing where the decision is still open.
What the section actually holds
Every difficult thing about a building is vertical. Head height under a beam. The fall on a drain. Where daylight lands at ten in the morning in February. How thick the floor has to be before the neighbour stops hearing the chair scrape. Whether the person who needs a level threshold can get in the front door.
None of those are visible in plan. All of them are legible in section at a glance, to a client who has never read a drawing before, which is the part that matters.
The 900mm at Kelvinhaugh Court
The yard flooded twice a year. Three previous schemes had proposed tanking the ground floor, which is a way of asking a building to win an argument with the river every winter for sixty years.
We drew the section instead: the workshop floor lifted 900mm above the yard, the yard left permeable, and the water given a day to sit and go. The whole scheme is in that one dimension, and we put the section on the front of the planning submission because it was the argument. You can see the result on the Kelvinhaugh Court project page.
Four things to ask your architect for in section
- The floor-to-ceiling height in the smallest room, not the biggest
- The threshold detail at the front door, drawn, not described
- Where the drainage falls to, and at what gradient
- The February sun angle on the deepest part of the plan
What it costs to skip it
It costs the same money, later, with a contractor on site. A section drawn at feasibility takes a day. The same information arriving as a site query in month four arrives with a preliminaries figure attached to it, and by then the frame is up and the cheap answer has gone.
