Windows are complicated—on top of providing a view, they also have to do everything a wall has to do. Doors are just as difficult. And to make things even more challenging, architects are faced with a seemingly infinite choice of window and door profiles for residential and commercial buildings, with so much variety among them that it is difficult—but not impossible!—to come up with universally applicable general principles for detailing them. This session identifies those principles and the technical basis for them, and demonstrates their application to the most common combinations of window profiles and wall types. Once understood, these principles and the thinking behind them will demystify the puzzle of window and door detailing, offering a simplified approach to design.

In this lecture with Christine Williamson of Building Science Fight Club, we will review flanged and unflanged systems in framed walls, windows in mass walls, windows in walls with continuous exterior insulation, sliding doors, and commercial windows, including storefront and curtain-wall systems.

After this session, participants should be able to:

- Identify the three most common approaches to structurally securing windows in building openings and describe the different effects of each method on water control, air control, and thermal control.
- Describe the two-stage seal approach to window and door detailing and explain why it works.
- Describe the most common methods of accommodating continuous exterior insulation at window openings.
- Anticipate common concerns about our proposed water, air, and thermal control strategies, particularly those related to constructability and cost—and respond to objections with the confidence that comes only from  mastery of the technical issues.