An Interesting Problem in Central Park: What the Restoration of Belvedere Castle Teaches Residential Architects about Leaks, Condensation, and Air Quality in New Construction and Retrofits

with Christine Williamson
1.25 AIA CES Learning Unit|HSW

The architect’s nightmare isn’t the one where you show up for the final trigonometry exam completely unprepared or you’re at Trader Joe’s with no pants on—the architect’s nightmare is getting a late-night call from a client who blindsides you with a serious problem you never saw coming. And it’s ten times worse when you’ve done a good job. The restoration of Belvedere Castle in Central Park—in which a folly designed by Frederick Law Olmsted was converted into conditioned space—was undertaken with extraordinary care by a team of intelligent and experienced designers working with some of the best subcontractors around. But it developed a real problem as algae began growing on its interior walls. The source of the problem turned out to be fascinating in an unexpected way: Because of the Covid-19 lockdowns, New York City’s air quality improved significantly, and it was air pollution that had been inhibiting the growth of algae on damp surfaces. In a cleaner environment, the algae bloomed. Happily, fixing the problem turned out to be relatively simple and inexpensive, because the analytical tools of building science allow us to understand the practical mechanics of what is happening—this is the simplicity on the far side of complexity.

This course will enable participants to:

1. Describe the three fundamentally different rain water management strategies in buildings

2. Identify the three approaches to condensation control and describe which ones were at play at Belvedere castle

3. Articulate how the three approaches to condensation control are applied in typical residential design

4. Describe specific commonly proposed design changes to a standard cavity insulated residential wall that would make it more risky or less risky from a condensation control perspective