In rehabilitating the building, +VG Architects was tasked with changing the building’s use from light industrial to public assembly, a challenge that required adherence to code and safety regulations while preserving the building’s historical integrity and as much as possible of the public’s view of the powerhouse’s original operation areas and equipment.
The power station, divided longitudinally into a generator hall and inner forebay, measures 587-feet long and 102-feet wide, totaling 59,874 square feet. The 1-story, symmetrical, rectilinear structure is clad with Queenston blue dolomite limestone rusticated blocks, voussoirs and keystones. Its hip roofs feature green tiles with copper-clad brackets, eaves and soffits.
The vast generator hall is the power station’s principal space, soaring 64 feet from the floor to the underside of the roof. The hall’s character-defining elements are the 11 generators; the long rows of white cabinets holding oil-resistance switches, the oldest type of circuit breaker; the traveling overhead crane that lifted the generators to facilitate removal for maintenance and repairs; and the hall’s unobstructed sightlines of these artifacts.
A visitor galley and viewing deck along the north wall hosted a stream of visitors, testament to the public’s interest in engineering technology during the early 20th century and CNPC’s pride in its ground- breaking setting.
Water entered the powerhouse through the inner forebay on the building’s east side. The inner forebay contained the fine ice-rack screen that strained debris and ice before the water flowed into the mouths of the penstocks, the large intake pipes that delivered the water to the turbines.
Other components include the gathering weir and outer forebay, which channeled water from the river into the power station, and the wheel pit, which descends 165 feet to a narrow cut into bedrock running the length of the generator hall that contains the turbines.
Thanks to the excellent condition of the station’s interiors, the interior design team was able to focus on the planning of the space and circulation in the generator hall and inner forebay for their conversion into exhibit, entertainment, retail and food-service areas.
Today, visitors enter the building through the north entrance’s monumental bronze double doors and proceed through a new vestibule and ticketing area into the generator hall. From there, the original portals with rolldown doors that separate the inner forebay and generator hall lead visitors into the inner forebay, now a retail store with capacity for future dining and entertainment additions.
At the project’s outset, a cofferdam was built between the outer forebay and the Niagara River to dewater the forebay. This was done to ascertain the condition of the building’s foundation and submerged stonework, to undertake necessary repairs and to build the inner forebay’s new dry basement.
Indeed, the water-filled inner forebay underwent the most significant intervention. Originally, the basin extended the length of the powerhouse. Now, only a central section, 98-feet-wide, was retained to show how the semi-exterior space functioned: Water entered under the submerged arches of the inner forebay’s outer wall and flowed up to the fine ice rack. Around this open section, the team poured concrete walls at the rear and the sides to create a dry basement for new building infrastructure, including HVAC, plumbing, electrical rooms, and fire safety and emergency escape routes. Above the basement, a new floor slab was poured for the retail and presentation areas. By burying the infrastructure, the inner forebay’s open sightlines were preserved.
PHOTOS: David Lasker Photography, unless otherwise noted