Walk through the older streets of Melbourne and look up between the terraces. Every so often the buildings part around a narrow shaft of sky, built there on purpose so that daylight could reach the kitchens and hallways in the middle of the house. That shaft is called a lightwell.

It is the most honest device in architecture. No machinery, no mirrors, no trick. Just a decision, made at the drawing stage, that the darkest rooms in the building deserve the sun, and a piece of design that quietly delivers it every day for a hundred years.

That is what we do to energy bills. The sun already sends your roof more energy than your home can use. Our job is the shaft: the engineering that brings it into the heart of the house, stores it for the evening, heats your water and your rooms with it, and does it so plainly that you can check the working yourself.

The company began under our engineer's own name, and a piece of it is still here: his first name, Onur, carries the old word for light inside it. When we became Lightwell, the light stayed. It was always the point.

A lightwell is built once, at design, and works for the life of the building. That is the standard. An engineer's name on every design, and everything in daylight.