Abstract:
Green buildings have achieved an increased importance in the New Zealand construction industry since the establishment of the New Zealand Green Building Council in 2006 and the introduction of the Green Star NZ rating tool soon after. This increase in importance has been reflected in green building certifications becoming a key feature of the New Zealand commercial property landscape. While overseas studies have shown that green building ratings tools can impact the initial construction cost, ongoing operational costs as well valuation of the building in terms of lease rates and sales price, to date no formal analysis has been undertaken on this in New Zealand. This study has investigated whether certified green buildings cost more to construct than non-green buildings in New Zealand. The study used Green Star NZ v1 to define a certified green building in the New Zealand context and collected cost data from 21 Green Star NZ v1 certified buildings, and compared this data to a control set of cost data from the Rawlinsons New Zealand Construction Handbook. The data was analysed in five different groupings (i) the entire green building data set (ii) 3 to 5 storey buildings (iii) 6 to 15 storey buildings (iv) 4 Green Star buildings and (v) 5 Green Star buildings. The study determined a statistically significant increase in construction cost for two of the five groups, the entire green building data set and the 3 to 5 storey buildings. The third group of 6 to 15 storey buildings did not experience any statistically significant difference in cost while the fourth and fifth groups, the 4 and 5 Green Star buildings, had inconclusive results.
