Szabi and I went to the same primary school. Years later, when he needed a logo for his electrical business, he knew who to call.

He fits wired, mains-connected smoke and fire alarms, which is a specialist trade, and he wanted a logo that says so at a glance. He's not an artistic person, and he loves negative space. That told me the logo had to be very simple.

So I built it from what he actually does: a smoke alarm, a flame and a wrench. The wrench is cut out of the flame, so the fire and the fix are one shape. Navy for trust, amber and hot pink for the heat, and a sturdy typeface that looks like the work.

First idea was the right one, and he loved it straight away and he's using it now.