Christchurch workforce moves west

The first buildings of the King Edward Barracks (KEB) development represent a new urban design strategy for Christchurch and are a significant departure from the old Christchurch city model, says Warren and Mahoney architect and Principal Graeme Finlay.

The development, he says, is further evidence of the migration west of the city’s working population to be based along the Avon River.  Ironically, the area was once the historical commercial centre of Christchurch, and known as West End in the nineteenth century, a name which has recently been reclaimed.

The design master plan makes maximum use of a large city block by combining commercial, government and residential accommodation in a prime location bordering Cambridge Terrace, and Hereford, Cashel and Montreal streets.

It is says Finlay “a truly mixed development.”

The brief from Ngāi Tahu Property required the development to reflect the values of Ngāi Tahu and to record the varied Ngāi Tahu and European history of the site. Phase One of the $85 million development has two office buildings of 6,500 sq metres and 7,500 sq metres, and a 20,000 sq metre gross floor area multi-storey carpark. The proposed Phase Two will include two more office buildings and Phase Three comprises 70 apartments; however these still require further design and are subject to testing of market demand. Unusually for a commercial development, the whole site will enclose an urban park, to be known as Ngā Māra a Te Wera (The Gardens of Te Wera).

Warren and Mahoney created the Masterplan for the three-phase development and project architect Vanessa Carswell, who is also a Principal of the multidisciplinary architecture practice, says the architects have been able to create a better environment for the city by “rethinking the typical urban block.”

Laneways and a public garden have been created within the block, which is sheltered from the winds and orientated to capture the sun. The project represents the site developers and owners, Ngāi Tahu Property’s long term relationship with the city, and their strong desire to create a lasting space and amenities for the public rather than just a typical block of commercial buildings.

The site, bordering the Avon River, is of significant cultural and historical value. Ngāi Tahu is the current owner of the site and has occupied this important mahinga kai area for centuries. It was also the location of the old King Edward Barracks where soldiers trained and left for duty in both World Wars. Since the 1930s there have been two police headquarters on the site, the most recent of which was imploded after the earthquakes.

The central Gardens will include a pathway to enable pedestrian flow from the Bridge of Remembrance through to the Civic Centre and the Art Gallery.  The park will showcase the rich Ngāi Tahu and European history through its design, including a number of commissioned artworks. Early Ngāi Tahu settlement will be honoured with storyboards included in the public space and some seats have been constructed to reflect early reed boats called mokihi. Native planting will be included in the central courtyard together with exotic deciduous species.

The advantage in being able to design a complete city block say the architects, is a much better use of land. “We have created a campus style commercial precinct with an inner courtyard,” says Carswell.  Office accommodation enjoys natural lighting from two sides and the courtyard brings people into the heart of the site. “There are no back alleys with wasted space and the buildings are better able to deal with overheating and shading.”

The development has adopted the latest earthquake technology. One building is base isolated, while the other one has a buckling restrained bracing system. Says Carswell: “It goes beyond and above code requirements, in order to meet the new client demand for seismic resilience.”

Both Phase One buildings will have photovoltaic panels on their roofs to generate power for the complex. Both buildings will be Greenstar rated, as well as holding NABERSNZ energy ratings. This energy rating system is based on an Australian environmental and energy rating system. The carpark will include state of the art parking for bicycles, as well as charging facilities for electric vehicles, licence plate recognition and red/green way finding and parking technology.

Innovative, too, is the use of a District Energy Scheme (DES) to service the energy demands of the entire site. Following the earthquakes, Christchurch building developers had an opportunity to think more sustainably about this aspect in their rebuild projects. Engineers Aurecon designed a central energy plant to service all the buildings across this city block. The DES draws water from an aquifer and passes it through a heat exchange unit before reinjection back into the aquifer. The plant harvests the heat energy from ground source water.

Although it has been designed primarily for the KEB site, the DES has the ability to link to adjacent sites that use the same system, including the Civic Building which houses the Christchurch City Council, and the Arts Centre, which both run similar systems.

“Once all the buildings are constructed, the DES will be able to share energy between them”, says Carswell. “This makes for more efficient and effective energy use, for instance residential units tend to have more heating demand, while offices have more cooling demand. Energy requirements between residential and commercial premises peak at different times of the day.”

Finlay is enthusiastic about “democratisation of space.”

“It really feels in this rebuild that space, action and vibrancy is being given back to the people of Christchurch, whereas corporate offices once fronted directly onto the street, and there was no way around them, or through them. Now there is this idea that the city is all about people. There are minimum standards re sustainability and ethical standards for our community.

“There really has been a colossal movement as buildings come together. There has been a shift along the river and I think the city will really come alive in terms of its daily life.”

Gordon Craig, senior development manager for Ngāi Tahu Property, says the iwi is proud of the development and its contribution to the “new” Christchurch.

“We wanted to create a place for people and a people place. We want the public, not just the tenants, to come into the site, and to contemplate the buildings and the place.