Gilberts helps minimise impact of green belt development

Working on the design & build project for contractor Blenheim House Construction (BHC),
Gilberts Blackpool has produced a natural ventilation strategy to a bespoke design, to ensure the architecturally-dramatic new Activity Centre at St George’s School Weybridge will be appropriately aired, irrespective of occupancy and activity levels within, and with minimal impact on its external surroundings.

“The project was a challenge that we were confident Gilberts could meet,” explained BHC project surveyor Joe Anderson. “The site geography provided challenges: the building has been sunk into the surrounding landscape to give level approaches at ground and second floor- there’s a height difference of at least 8m- which impacts on airflow around the building.

“Gilberts also had to deal with the ventilation’s ability to cope with occupancy and activity differences ranging from a whole-school assembly of 1,000 or more pupils and staff, through to part of a class using the climbing wall or cricket nets. It had to balance human occupancy and activity alongside the potential heat gain as a result of large areas of the building featuring floor to ceiling glazed sections.

“Beyond the technicalities, the ventilation had to reflect the high aesthetic standards of the project.”

With its in-house design and manufacturing capability, Gilberts was able to engineer a tailor-made rooftop ventilation terminal (penthouse) design to deliver the required air flow and a weathertight fit onto and through the omni-directional curves of the roof. In total, 16 PHH75 roof terminals, each 1900mm x 100mm x 14mm, with boost fans in those over the main sports hall area, have been fitted to the Glulam beam and CLT panel roof. Almost all of the penthouses provide natural ventilation into the sports hall below; those over the lower areas of the roof feature additional fan assistance to ensure adequate delivery of fresh air in their more sheltered location.