Local conditions
The sun is in the room before the staff are
East Glass, Ten Past Seven
Brisbane and the Gold Coast sit at about 27 and 28 degrees south, and at that latitude a
summer midday sun is close enough to overhead that a north elevation with any slab
overhang largely looks after itself. The whole problem is east and west, and it is a
low-angle problem: sun that arrives underneath the overhang, underneath the awning, and
straight down the length of an open-plan floor. By ten past seven in January the sun is
already well up over the ocean, and every east-facing desk between Southport and the CBD
is looking into it. Towers over the Broadwater and along the river get it twice, once from
the sky and once off the water, which is a nice view and a miserable place to read a
spreadsheet.
Then there is the assumption we spend half of every commercial measure unpicking. Most
south-east Queensland office glazing is already tinted or performance-coated, and the
facilities manager reasonably takes that as the sun dealt with. It is not. A tint changes
how much solar energy crosses the glass; it does very little about a bright source sitting
fifteen degrees above the horizon in somebody's field of view. Glare is a contrast problem,
and the only thing that fixes contrast is putting something between the eye and the sky.
Your Home, the
Australian Government's guide to glazing, makes the same distinction between heat
control and visual comfort.
On the Coast, add salt. Componentry within a few streets of the water works harder than
the same componentry inland at Robina or Nerang, and the part that gives up first is never
the fabric. And if the glass in question is west-facing, full height and unshaded, we will
say so at the measure: an internal blind is the second-best answer there, because
shading the
glass from outside stops the heat before it arrives. An
external awning costs more and does more, and no roller
blind ever made can undo heat that is already in the room.
