Author(s)

PRISCILA BESEN, PAOLA BOARIN

Abstract

Heritage conservation and energy efficiency considerations have converged in recent years. While new construction has focused on improved thermal performance to achieve high comfort levels in an energy efficient manner, the retrofitting of existing buildings with the same principles has just started to be recognised as a strategic measure, since they form much of the building stock and often have poor performance. In this context, listed heritage buildings play an important role and have the potential to lead as best practices. In fact, given their cultural significance, they are the most likely to remain for a long lifespan, so their adaptability to the future needs is of high importance. Although thermal retrofits were seen as a threat to conservation until recent decades, now they started to be recognised as a measure to help with the protection of heritage, ensuring healthy environments for a longer lifetime. In New Zealand, however, there is a gap between heritage preservation practices and environmental sustainability considerations. Existing policies only focus on other types of upgrades, such as seismic strengthening, fire safety and accessibility. In terms of industry practice, most retrofits only include shallow improvements, without making deep modifications to energy efficiency and indoor comfort. Therefore, there is the potential to use certification schemes for the retrofit of historic buildings in New Zealand. A comparison between three existing international retrofit certification schemes is presented, analysing GBC Historic Building®, EnerPHit and BREEAM® RFO. Each scheme has shown to have benefits and limitations – GBC® and BREEAM® provide a holistic approach, while EnerPHit focuses on energy and comfort. All schemes are relevant to NZ, as certified thermal retrofitting can bring long-term benefits in regards to energy savings and the health of the occupants of historic buildings, which are intangible aspects commonly disregarded in NZ building renovations.

Keywords

thermal retrofit, heritage buildings, energy efficiency, thermal comfort