The Footcandle is King
Certainly there is a balance of quantity and quality, and every project has its own unique set of parameters, goals, and requirements.
One of the most common questions we are asked, on all project types, is, “How much light is in the space? Show me the numbers”. More often than not, the answer to that question is only part of the story. A good solution is often much more reliant on the quality of light delivered, and in making sure that all aspects of the space are considered as part of the design process. A successful lighting design solution requires careful coordination, prioritization of goals, and thoughtful analysis.
At a minimum, ask yourself:
What is the preferred color temperature of the source(s)?
Are there different sources?
What are IES recommended light levels?
How will the space be used?
What are the project goals, the inspiration, character, and organization?
Are there opportunities for layers of light?
Are there features, accents, highlights?
Is there opportunity for vertical illuminance?
Is there opportunity for uplight?
How do we mitigate glare?
How much controllability do we give the occupant?
Is the space dimmable? By what method?
How does the room respond to daylight?
What does code require?
There are countless examples of spaces that have 30-50FC on the floor, but sitll feel dark and uncomfortable. Meanwhile, other spaces with much less FC on the ground can feel very comfortable and bright, because all or some of these other design factors have been properly addressed. In the end, a good design requires a complete and comprehensive approach to a solution that is tailored to each individual space.