Daylighting and natural ventilation aren't add-ons. They're architectural commitments that get baked into the building at the earliest design stages, and they're nearly impossible to retrofit later without major cost.

Light shelves bounce sunlight deeper into floor plates. Clerestories push glazing above eye level for glare-free ceiling illumination. Cross-ventilation relies on openings on opposite facades driven by wind pressure differentials. Stack effect pulls air vertically through temperature-driven buoyancy. Each strategy demands specific decisions about building orientation, massing, section, and envelope.

For PPD, the question isn't whether these strategies exist. It's when to select one over another, and how that selection ripples through structural systems, mechanical sizing, envelope design, and cost. A south-facing light shelf works brilliantly in a clear-sky climate but accomplishes almost nothing under perpetually overcast conditions. Cross-ventilation requires a narrow floor plate, which affects structural bay spacing and rentable area. Stack effect demands vertical connectivity between floors, complicating fire separation.

The ARE tests your ability to evaluate these trade-offs during preliminary design. You'll need to weigh competing factors: energy savings against first costs, daylight penetration against glare risk, ventilation rates against acoustic privacy. The practical depth of a daylighted zone, typically 1.5 to 2 times the window head height, drives decisions about floor plate depth and furniture layout before a single duct is sized.

These are the decisions that lock in a building's energy performance for its entire service life.