Hockessin Athletic Club, Hockessin, Delaware

Share this Case Study


  • Pool builder: Carlton Pools
  • Mechanical Engineer: Services Unlimited, Inc. Design/Builder: Rocchi Construction, Inc.
  • Architect: Rocchi Construction (Phil McWilliams, AIA), Architect of Record – Rubeling & Associates, Inc. (John DiMenna, AIA).
  • HVAC Manufacturer: ICE – Industrial Commercial Equipment Manufacturing Ltd.
  • Specs: 120' long x 146' span (36.6m x 44.5m)


The owners of the Hockessin Athletic Club wanted to build an exceptional, state-of-the-art, full amenity health club from the ground up. Wanting to offer a significant competitive advantage, their ambitious vision was to create a facility that would serve the needs of a multi-generational community and house a variety of aquatic programs, all within one stunning location. The club had to have a substantial "wow" factor and be the best facility in the area.


Architect Phil McWilliams of Rocchi Construction had heard about the remarkable OpenAire retractable roof enclosure at the Americana Resort in Niagara Falls, Ontario. He took co-owners Bob Carpenter and Roger Ralph to visit the enclosed waterpark so they could experience the amazing potential of an OpenAire enclosure and envision the "wow" possibilities it could have for the Hockessin project.

"We were completely blown away," says Carpenter. "After Phil, Roger and I visited the Americana, we knew we had to have it for ourselves!"

OpenAire designed, manufactured and built a 120' (36.6m) x 146' (44.5m), 17,520 square-foot free-standing enclosure to house four of the Hockessin Athletic Club's five pools: a large beach-entry recreational pool with slide, a warm water therapy pool, a four lane lap pool and a whirlpool. Another six-lane outdoor pool sits outside the enclosure, and opens only in summer.

The enclosure, made with a maintenance-free, thermally-broken aluminum frame designed to L/180 deflection criteria, is 20' (6m) high at the eaves and soars to 50' (15m) at its highest point. It has 18 operable roof panels that can open up to 7,000 square feet (almost 50%) of the roof area. 13 horizontal sliding doors and ten (10') aluminum and glass overhead doors open up more than 50% of the sidewalls, making it an outdoor facility during the summer months and comfortable, appealing, naturally lit space in cool or inclement weather.

"The fact that the building is an aluminum structure with a thermally-broken glazing system is great in terms of energy efficiency and cost savings," says Phil McWilliams, Architect, Rocchi Construction. "Plus, the ability to open up so much of the roof with just the push of a button is invaluable."

The highly energy efficient system uses up to 100% makeup fresh air, and works in conjunction with a heat recovery system to exhaust warm air. The only mechanical system requirements are for winter months, when some dehumidification is needed and some heating is needed to keep the pool area warm. But even in cold weather, the glazed structure is designed to trap heat from the sun, maintaining a comfortable temperature while keeping heating costs low.


The Hockessin Athletic Club opened in June 2007 to tremendous response. The community has fully-embraced the new facility – it is now a point of pride for the community, attracting large numbers of new members every year.

"A traditional natatorium is always dead in the summer time," says McWilliams. "This structure gives people the feeling of being outside, but when it’s not so nice out, it can protect them in a beautiful naturally-lit space that’s the closest thing to being outdoors."


No A/C requirements and reduced heating and dehumidification needs translates to significant savings on heating and cooling costs. In winter, heating is only needed to supplement the solar gain heat captured by the glazed panels, and in summer months, the facility opens up, allowing fresh air to circulate. And all that sunlight saves electricity; no artificial lights are used during the day.

"Much to my pleasant surprise, even on hot humid days characteristic of Delaware summers, being within the OpenAire structure felt cool," says Roger Ralph. "Our ability to open the ‘garage’ doors even on still days somehow resulted in a cooling breeze."


Closing the roof and doors during inclement weather and cold winter months allows uninter- rupted, revenue-producing fun for the club’s members.

"The OpenAire structure literally makes people’s jaws drop when they tour the club," says Carpenter. "OpenAire has helped make the Hockessin Athletic Club one of the most impressive facilities in the country."

Speak with an OpenAire design expert

Contact us today to get the conversation started.