Published: 18 May 2015

Architects are using daylight analysis to better tell the story of a design to clients. Together, renderings and analysis build a more complete — and more compelling — case for design, writes Carl S. Sterner.

As architects, we are trained to use daylight to shape the character and experience of the spaces we create. We are skilled at exploring the visual, experiential aspects of daylight. We are adept at creating striking renderings — those beautiful depictions of light and shadow that viscerally communicate the character of the design. These images are easily woven into the narrative of our design intent, and easily understood by clients.

But there is a critical element missing from this medium: the practical issue of whether the daylight actually works. Are our renderings actually representative of the lighting in the space, or are they evocative works of fiction? Do they capture typical conditions or a unique moment? Does our design actually supply the lighting required?

As-existing CGIs

View along glazing towards pyramid, showing very high light levels at perimeter but becoming dark very quickly within the space.
Existing terrace without any form of cover at all limits the potential all weather seating options.
View within pyramid showing patent glazing — the effect of this is extreme levels of glare and overheating within the space as well as poor insulation so heating over winter likely to be a cost issue.
View upwards to show current ceiling arrangement.

Renderings are unable to answer outcomes-based questions: Is this classroom well-lit for most occupied hours? Is there glare in the conference room? Are roof lights an effective strategy for improving day-lighting in our office? How do they compare to light shelves? Should there be more glass on the north or south façade? A good design needs more than poetry: it needs to work — not just sometimes, at that magic golden hour, but every day, every hour.

These are questions, of course, for which daylight analysis is well suited. Nearly every space has lighting requirements, and day-lighting analysis can show how well a design meets those needs. It can help designers proactively identify problem areas, measure progress toward project goals, and compare design options. Physics-based analysis allows designers to build performance into the very fabric of their designs, and thereby weave a strong objective case into each concept.

This insight is increasingly easy to get, thanks to new tools that make daylight analysis accessible, quickly enough to be an integral part of the design process.

But the point is not simply that daylight analysis can be a great design tool (although this is certainly true). The point is that it is also a great tool for communication — for telling the story of a design to clients. The combination of qualitative and quantitative elements is especially powerful. Renderings put an expressive face on otherwise opaque numbers; and analysis backs up the vision with clear, impartial data. Together they build a more complete — and more compelling — case for a particular design.

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