Petrie expansion adds valuable research space

Their heads have always been in the clouds but now York’s atmospheric scientists will be even closer to the cirrus formations and ozone they love to study in the Earth’s stratosphere. Closer by about three metres.

That’s how much taller the Petrie Science & Engineering Building is now that builders have added a partial fourth storey. It extends across the south side and houses two observatories, a lab and a rooftop deck for testing equipment.

Left: The newly renovated and expanded Petrie Science & Engineering Building on York’s Keele campus

For the first time, York’s previously dispersed atmospheric scientists will be under one roof. Up to now, they have been doing their research from a dark little observatory jury-rigged in a concrete storage space on the fourth floor of the Computer Methods building, a non-York facility, in the remote northeast corner of Keele campus.

The difference between the old facility and the new "is like night and day," said Ron Ogata, York renovations manager.

The Petrie extension is airy, bright and spacious. A corridor extends the length of the facility between two stairwells and leads to a LIDAR (laser remote sensing) observatory and an adjacent lab, and an atmospheric observatory/lab. From 1.5-by-1.5-metre roof hatches and skylights above each observatory, York’s scientists will fire red and green laser beams into the night sky to measure cloud density and the thickness of the ozone layer.

"York scientists are known for their premier research in atmospheric science," said York Prof. Jack McConnell, principal investigator for the project.  "This new facility is only going to help us maintain that edge."

The idea of building up rather than out had been around for many years. Gordon Shepherd, professor emeritus of space science and director of York’s Centre for Research in Earth & Space Science, proposed it as part of an application for funding for a research project called "A Community Approach to Multiscale Air Quality Modelling and Forecasting". The project should lead to improvements in forecasting air quality and air pollution in Toronto, southern Canada and beyond. In 2004, the Canada Foundation for Innovation granted $2.3 million for the project’s research infrastructure. The grant has paid $600,000 for a $2-million super computer (offered to York at a generous discount by IBM) to be used for air pollution research and forecasting, and for other equipment. The grant has also covered $1.3-million of the $1.7-million cost of the Petrie extension. 

The hatches are among the most exciting features. "The holes in the roof are a big deal," said Ogata. "They’re unusual." There are two 1.5-by-1.5-metre hatches opening onto the roof over the LIDAR observatory and 1.5-by-1.5- and 1-by-1-metre hatches over the atmospheric observatory. Most commercial hatches are used for climbing onto the roof or lowering equipment into the room below. But because scientists need an unobstructed 180-degree view of the night sky, the doors on these hatches open parallel to the roof.

Right: Jack McConnell

To enable all-season research, builders divided the LIDAR observatory into two rooms. One room is insulated so that hatches can be left open for hours in the most frigid winter weather. The other room is a lab where scientists can stay warm.

When York senior planner Peter Thompson called for tenders, he underestimated what could be built with $1.7 million. Petrie was not designed to be expanded upwards. For the money, Thompson expected to be able to build two small labs and a common vestibule, and to extend a single stairwell. But the winning design from design/build firm BirdNorr proposed a spacious 160-square -metre expansion spanning the entire south side that would include observatories, lab, common area, extended stairwells and – bonus –  an extension of the elevator shaft.

"We actually ended up with quite a bit more than we thought we could get," said Thompson. "We were really pleased. But the budget was very tight and we had to be very mindful of keeping the project on budget every inch of the way."

Builders mobilized in July and started work the first week in August. Petrie’s roof was not designed to take any extra load, so the builders had to construct a separate frame to support the extension. They extended Petrie’s existing columns then attached cross beams, which carry the entire weight of the new addition. Builders faced two other major challenges: access to the construction site and working on top of an occupied building, said Thompson.

Left: Ground-level view of the new Petrie

Because there was no elevator access to the roof, building materials had to be lifted by crane. And because Petrie is located on the busiest pedestrian walkway on campus, "the objective was to get the lifting and crane activity completed before classes started in September," said Thompson.

Working on top of the building posed challenges. "We had to penetrate the roof membrane to make connections and cut holes in the existing roof for drainage," said Thompson. "People might have been disturbed, but they weren’t displaced."

The site was often active by 4am and on weekends. "We tried to work around people’s schedules," said Thompson. Striving for minimum disruption, construction workers also cleaned up as they went, which is not always the case in other builds. "It wasn’t an easy place to work," said Ogata.

The cranes left long ago. The observatories were completed by Christmas, in advance of the January target, said Thompson. Except for a new elevator, which will be installed by the beginning of March, the place is ready for occupancy – and the occupants have started moving in.

This article was written by Martha Tancock, York communications officer.