North Coast Regional Botanic Garden Glasshouse

The North Coast Regional Botanic Garden was established in 1988 about a kilometre from the centre of Coffs Harbour, on the north coast of New South Wales; its rainforest section, planted in 1987, holds some 350 species. Covering around 20 hectares, roughly half of it natural forest and mangrove, the garden is otherwise devoted to outdoor plantings: north-coast flora, rare and threatened species, exotic collections from regions near 30 degrees of latitude, and a Japanese friendship garden laid out with advice from Coffs Harbour's sister city, Sasebo.

The glasshouse answered the need for a fit-for-purpose facility in which to grow, conserve and display tropical and subtropical plants that cannot survive outdoors, while supporting research and education. The project, valued at $1.46 million by the city (the state government's release gives $1.4 million), was funded jointly by the Australian Government, the New South Wales Government and the City of Coffs Harbour, with volunteers from the Friends of the North Coast Regional Botanic Garden contributing their time. The Mayor of Coffs Harbour opened it in June 2022. None of the sources consulted names the designer or the builder.

The building has two complementary parts. The tropical house is held between 25 and 32°C, primarily by passive solar heating: large north-facing windows gather warmth, while stone walls and pathways act as thermal mass. A 9-kilowatt heating system takes over on cool nights and in winter. The roof and some of the walls are clad in gel-coated 'webglas' panels intended to reduce heat loss. Computer-controlled cross-flow ventilation opens louvres once the temperature reaches 32°C, and watering is by micro-sprays and drippers.

The adjoining shade house is open to the outside air and shields plants from temperature swings much as a rainforest canopy would; it has drip irrigation and subsoil drainage. Beneath both spaces, 180 tonnes of gravel and a network of drainage pipes keep the soil free-draining. Around the building, arid-landscape beds, including one of cacti and succulents, a fernery and a water feature complete the setting.

The tropical house holds very cold-sensitive plants from tropical regions such as Indonesia and Malaysia. The tall, red-stemmed lipstick palm (Cyrtostachys renda) dominates the northern window, and beneath it grows Licuala orbicularis, a rainforest palm from Borneo, where it is used to make hats, wrap food and thatch roofs.

The shade house displays the garden's extensive bromeliad and orchid collections together with ferns, anthuriums and other shade-loving plants; taro is also listed among the plantings. The stated aim is to show, for conservation, research and education, species that are not normally grown in the Coffs Harbour region. Outside, an arid-landscape garden, a fernery and seasonal flower beds frame the building.

The glasshouse stands in the middle of the botanic garden, whose address is the corner of Coff Street and Hardacre Street, right beside the Sensory Garden. The garden suggests moving from the humid heat of the tropical house to the cooler shade house, where a bench invites a pause. A visit can continue into the rainforest planted in 1987 and the natural forest and mangrove areas that cover about half the site, through the Japanese friendship garden and among the rare and threatened plants of the north coast, including the swamp orchid Phaius australis. Central Coffs Harbour is only about a kilometre away.