Christchurch Civic Building
Te Hononga

Public
Green Star

Client: Christchurch City Council & Ngai Tahu Joint Venture

Architect: Athfield Architects Limited

Location: Christchurch Central

Completion: September 2010

eCubed were the ESD consultants to the project team, offering advice throughout the design process and acting as Green Star accredited professional.  The building was being developed by a joint venture between Ngai Tahu Property and Christchurch Civic Council.

The building uses a tri-gen system providing heating, cooling and electricity fuelled by biogas, which allows it to operate in a carbon neutral way (a New Zealand first).

With a rating of 83 points it is one of New Zealand's highest rated Green Star building and was also awarded four out of a possible five points for innovation.  It is an extensive refurbishment of what was the New Zealand Post building on Hereford Street. 

ESD workshops were held at the concept and preliminary stages to set the environmental goals for the building.  Originally the building was targeting a five star rating, though once the use of tri-generation fuelled by council landfill gas became an option, a sixth star came within reach.   The landfill gas has an extremely low carbon factor and, depending on how the building is operated, allows the building to be carbon neutral – a New Zealand first.  The use of tri-gen allows the landfill gas to be used to provide heating, cooling and generate electricity.  At times the building has the potential to produce more than it requires so some services are shared with the neighbouring Art Gallery, which has a 24-hour demand for conditioning.

Sustainable features included in the Christchurch Civic Building are:

• Biogas fuelled tri-gen to provide heating, cooling and electricity

• Daylight dimming and occupancy controls on the lighting

• Bicycle parking, showers and lockers for a significant proportion of council staff

• Rainwater recycling for use in the toilets and landscape irrigation

• Low-flow sanitary fittings to reduce water consumption

• Solar hot water is expected to provide over 75% of the building’s hot water needs

• The double skin facade allows the offices to be naturally ventilated, and automated blinds to limit heat gains and glare

• Underfloor air delivery only conditions the lower occupied zone of the very high ceilinged office floors

• Re-use of existing building facade and structure, additional precast panels have been reused in the landscaping

• The use of environmentally preferable materials with Environmental Choice certifications, low levels of VOC’s, ODP and formaldehyde

The many features included in the building presented a challenge when carrying out the energy and thermal computer simulations.  These simulations were used to inform the design process with regards to glazing type (including the double skin facade) and HVAC system type as well as for the requirements of the Green Star submission.  While a building may typically include one or two features which require specific modelling, the Christchurch Civic Building required us to push the modelling software to it limits – in fact the tri-gen system could only be correctly modelled due to a software update which occurred during the design process.  We also completed the daylight modelling to assess the penetration of natural light into the office floors.

Awards —

• AGM Interior Award: Workplace - Finalist 2013

• NZIA New Zealand Architecture Award - Public Category - 2013

• NZIA New Zealand Architecture Award - Sustainable Architecture Category - 2013

• NZIA Canterbury Architecture Award - Sustainable Architecture Category - 2013

• NZIA Canterbury Architecture Award - Public Category - 2013

• NZIA Canterbury Architecture Award - Interior Architecture - 2012

• NZIA Canterbury Architecture Award - Public Category - 2012

• NZIA Canterbury Architecture Award - Sustainable Architecture - 2012

• PCNZ Rider Levett Bucknall Property Award: Hays Commercial Office Award - Excellence 2012

• PCNZ Rider Levett Bucknall Property Award: Resene Green Building Award - Excellence, Best in Category 2012