ENMAX Conservatory (Calgary Zoo)

The ENMAX Conservatory is not a new build in the strict sense: it extends greenhouses that were already part of the Calgary Zoo. The project rests on the complete renovation of two buildings, one raised in 1964 and the other in 1967. The zoo, now run by the Wilder Institute, occupies St. George's Island in the Bow River, a sheltered site that allows marginally hardy plants to be grown.

The works were registered for LEED certification in March 2008; the building was completed in 2009. Gibbs Gage Architects produced the design, described as the reuse and reinvention of two structures about forty years old. The name refers to the energy company ENMAX, which sponsored demonstration renewable-energy installations.

Sources differ on the certification level: the project registry and the architect give LEED Silver, while the encyclopaedia article on the zoo mentions Gold. The Nutrien Garden of Life appears in the zoo's current offer; its opening date could not be confirmed.

The transformation kept the steel frames of the two original greenhouses. On these structures the designers fitted new energy-efficient glazing systems, creating a more stable environment for a butterfly pavilion and an ethnobotany pavilion. The LEED registry data give the building area as about 3,070 square metres.

The programme goes beyond display houses: it includes flexible education spaces, a banquet hall and a tea house or chapel, linked by public multi-purpose areas. Solar panels and other ENMAX-sponsored features demonstrate clean-energy technology for visitors. The glazed structures are surrounded by native plantings that support regional biodiversity. The sources consulted do not give heights or precise volumes for the spaces.

The zoo presents the Nutrien Garden of Life as a lush tropical garden in which to discover the plants that make our world possible, in the spirit of ethnobotany, the study of relationships between plants and human societies. Species highlighted on the zoo's website include allamanda, cannonball tree, choco palm, Jamaican poinsettia, powder puff tree, soursop and white stopper.

The Garden Gallery, described as full of beauty and butterflies, holds exotic butterflies and moths, mostly in spring and summer, including Atlas moths and red admirals. The conservatory is also tied to a Wilder Institute conservation programme for a native butterfly, the half-moon hairstreak.

The conservatory stands inside the Calgary Zoo at 1300 Zoo Road NE and is visited with zoo admission. An hour is about right, longer for those who linger among the butterflies.

It makes one of the city's best winter outings, since the houses stay warm while the island is under snow; spring and summer are richest in exotic butterflies. The rest of the zoo, with its animal zones, fills out a full day. The building's banquet hall and tea house, part of the original programme, also make it a venue for gatherings, so some areas may be in use for events.