Havergal College uses copper to bridge tradition and sustainability

by arslan_ahmed | March 24, 2023 10:00 am

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 By Larry Peters

Havergal College is an independent, all-girls school. Established in 1894, the school was built on farmland, but today stands within Toronto’s desirable Midtown area. A brook running through the centre of the 8.9-ha (22-acre) campus naturally separates it into two halves. On one side, the Upper School, finished in 1926, features buildings of limestone and leaded glass designed in the collegiate gothic style. On the other, the Lower School, opened in 1999, features contemporary elements of stone and timber.

Growing enrollment at the school offered opportunities to create more space and strengthen connections between the two areas. Architects Diamond Schmitt came on board to design an addition that would address “the unique topography of the ravine and woodland,” but also integrate the school’s “historic and contemporary architecture.” Principal Sydney Browne described how they used copper “to pick up on elements from the original buildings and look back at the most beautiful elements of what was there to knit the new and old together.”

Completed in late 2020, the new 2043 m² (22,000-sf) facility features a variety of teaching, common, and studio spaces, along with a dramatic, three-storey bio-wall, green roof, and outdoor courtyards.¹ The design team for the school’s addition chose to establish “efficient narrow floorplates” that “provide extensive daylight and views,” enclosed by a “new glass facade, [which was] punctuated by tall, perforated metal sunshade fins and articulated standing seam copper cladding.”

The project’s sustainability features helped it meet Toronto Green Standards (TGS) and achieve Leadership in Energy and Environmental Design (LEED) Gold certification. These features included:

• An airtight building envelope with minimized thermal breaks.
• Green roofs to reduce heat island effect and cool the roof itself.
• Planned photovoltaic panels on roof of northeast clerestory.
• Glulam structural elements for decking and for vertical timbers at the curtainwall.
• Extensive use of wood, certified by the Forest Stewardship Council, in study spaces, handrails, doors, and casework.
• Windows featuring insulated double-glazed units with low-e coating on surface #2, filled with 90 per cent argon gas.
• Roller shades incorporated into all glazing to manage solar heat gain and glare.
• Operable windows along east and north facades to reduce HVAC loads.
• Bird-friendly ceramic frit patterns applied to the #3 glazing surface.
• Stormwater collection system feeding into an on-site bioswale, removing debris and pollution.
• Low-use water fixtures and irrigation systems.
• Energy-efficient lighting and mechanical systems.

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“Environmental responsibility is absolutely a design issue. Whether it’s LEED or Toronto Green, these ideas are all connected,” says Browne. “Energy modelling was at the core of our sustainability work. We also focused on a palette of natural materials,” she added, “including timber elements for the structure, stone, felt for acoustics, plus the copper.”

Havergal’s leadership team and board of governors endorsed targeting LEED Gold early in the process, and the school’s director of facilities, Lisa Massie, was a strong proponent of pursuing sustainability at all stages.

 

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Many of Havergal’s original buildings utilize copper material for roofs, parapets, and flashings. The strength and resilience of these copper elements prove well-suited, especially for educational and institutional buildings with long lifespans. Copper’s natural resistance to corrosion and low maintenance requirements offset higher initial material costs, compared to metals, which require periodic painting, refinishing, or replacement.

The repeating rhythms of vertical copper panels on the exterior represent one of the building’s most striking features.

“The copper takes an existing material and uses it in a way so that it finds a modern expression,” says Jim Graves, project manager at Diamond Schmitt. “The standing seams add texture to the facade and will continue to transform for many years as the material patinates.”

The copper material complements the adjacent glass while evoking copper roofs and ornamentation featured on prominent educational, religious, arts, and government institutions found across eastern Canada.

According to Buttcon, the general contractor, from a construction standpoint, the facade was primarily a structural curtain wall with localized copper wall infill and masonry sections; therefore, copper is a good choice because it will outlast other similar finishes when used as an exterior. Further, copper ages with the building, withstands weather, and is typically a preferred and premium finish for metal clad buildings. Copper elements can last a century or more, reinforcing the principle of using materials wisely and in a sustainable way.

A metal fabricator manufactured more than 1021 m² (11,000 sf) of facade panels for the project. The cladding is made of 453-grams (16-oz) copper pans, with 50.8 mm (2 in.) of standing seams adding a textural pattern to the facade. Since Toronto can experience warm summer temperatures to well below freezing winters, the manufacturer included “a sprung edge to help reduce oil-canning and allow for expansion and contraction of the copper during varying weather conditions.” For the complementary copper parapets, the project team created 25.4-mm (1-in.) standing seams along the roofline to allow for an infill condition.

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The construction team also applied copper to areas where the old and new structures came together, applying a pan curb that facilitates a 152.4-mm (6-in.) structural joint. Copper’s workability helped it accommodate challenging conditions at these points, creating consistent and functional transitions.

“It is also nice to be able to do the wall and all flashings in one material,” says Graves. “The variability of what you are able to do with copper is greater than some other materials.”

For the projecting copper parapets with deep shadow reveals, the team created small returns along the length to account for changes in the depth of the back-sloping parapets. This flexible approach utilized a mitered parapet profile with 25.4 mm (1 in.) upstand at ends, and a special transition piece which could be s-locked in place.

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The new Upper School addition also interfaced with the existing buildings in different ways. For example, one long edge of the roof needed to maintain a structural gap of 52.4 mm (6 in.); the copper cladding had to allow for this movement with a back-sloping parapet at a vertical copper-clad curb above. The project’s copper installers developed a pan curb to facilitate this movement. At vertical expansion joints, conventional expansion joint materials were used behind copper cladding details to allow for the required movement.

The final design

The project’s overall design and effective use of copper earned the architectural and construction teams a number of honours, including the Ontario Wood Design Institutional Award and a North American Copper in Architecture (NACIA) award from the Copper Development Association (CDA).²

“This project takes full advantage of the versatility and longevity of copper as a building material. The judges were impressed with how Diamond Schmitt’s design combines copper and glass to complement the beauty of the outdoor spaces,” says CDA president and CEO Andy Kireta, Jr. “The addition at Havergal College Upper School represents an outstanding example of copper design in a building that prioritizes long-term sustainability and the well-being of students.”

Notes

¹ To learn more about this project, visit https://dsai.ca/projects/havergal-college-upper-school[6].

² To read an article on the North American Copper in Architecture (NACIA) award, visit www.ontariopanelization.com/news/havergal-nicia-award[7].

[8]Author

Larry Peters is project manager and architectural applications specialist for the Copper Development Association (CDA), a U.S.-based, not-for-profit association of the global copper industry, bringing together the North American copper and copper alloy semis fabricators, and global copper mining and production industries. To view more examples of how architects and designers are incorporating copper in today’s building systems, visit www.copper.org.

Source URL: https://www.constructioncanada.net/havergal-college-uses-copper-to-bridge-tradition-and-sustainability/

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