Lakeville, CT

Hotchkiss School Natatorium


The Hotchkiss School Natatorium is a competitive swimming and diving facility within a 212,000 sq ft  athletic complex. During its first winter, the owner reported problems, including brown stains and water dripping from the ceiling, efflorescence on exterior masonry, condensation on glazing systems, and heavy ice accumulation at roof eaves. The contractor originally hired SGH to determine the cause of these problems and the architect later retained us to design repairs.

Our investigation included observations at exploratory openings, water testing, air leakage tests, evaluation of infrared scans, and air pressure monitoring.


SGH determined warm, humid air from the natatorium was leaking into the exterior wall and roof systems; condensing on cold surfaces outboard of the insulation; and causing efflorescence, icicle formation, and water dripping. We concluded this leakage occurred because the natatorium enclosure lacked a continuous air barrier system and the mechanical system could not achieve and maintain sufficient negative air pressure in the natatorium. Additionally, SGH determined the enclosure’s thermal performance at and around windows could not accommodate the high humidity, leading to condensation on the glazing.


We recommended remedial work to reduce air exfiltration by improving enclosure continuity and to control indoor air pressure by modifying the mechanical system. SGH designed a new roof for the building, including the details for integrating the new roof with the existing walls. We provided part-time construction monitoring during the remedial work, which was fast-tracked to fit within the school’s prescribed time frame for repairs.

Project Summary



Completion Date
Repair & Rehabilitation
Building Enclosures
O&G Industries | Ellerbe Becket
Specialized Capabilities
Building Science | Roofing & Waterproofing

Key team members

Vince Cammalleri
Vince Cammalleri
Building Technology Region Head, East