Warm, healthy, and green historic buildings
Te Herenga Waka—Victoria University of Wellington PhD candidate Rachel Paschoalin’s research looks at how renovation guidelines can help create warmer and drier historic buildings.
Rachel's research investigates how to sympathetically retrofit historic buildings to reduce their energy use and greenhouse gas emissions, so they can continue our heritage, protect the climate, and serve their communities.
Her research is timely as it provides an alternative to the recent debates that saw historical character areas, like Mt Victoria in Wellington, accused of protecting damp, cold, and unhealthy rental properties from renovations. During the Wellington City Council’s Spatial Plan consultation over the past year, environmental and rental organisations such as Generation Zero and Renters United argued to reduce the size of character areas to enable more intensive, healthy development in inner-city suburbs.
In her research, Rachel interviewed architects, conservation professionals, engineers, asset managers, planners, and policy experts to understand what retrofit measures are suitable under local best heritage practice. She explored whether New Zealand could benefit from adopting international procedures.
"New Zealand's historic wooden buildings pose unique insulation difficulties. They often require carpenters with traditional skills, but our industry is small, making it harder to serve these needs at an affordable scale and cost,” Rachel says.
To develop guidelines, Rachel explored different retrofit measures while balancing the economic factors, heritage outcomes, and energy use. The measures range from installing roof and floor insulation, thermal curtains, double glazed windows, and various internal and external wall insulation options. Each has varying degrees of reversibility and appearance impact, so Rachel is using information gathered from interviews with experts to gauge the suitability of each measure.
Her initial findings identify that heritage experts are cautious when it comes to retrofitting’s visual, spatial, and material impacts. Conservation professionals were hesitant to adopt overseas' guidelines if they potentially introduce unforeseen moisture decay of existing fabric and do not satisfy New Zealand’s unique climate, seismic, materials, and construction methods. Instead, Rachel’s research found that guidelines should be tested locally, and local experts trained, before being adopted as solutions. However, all the experts also appreciated the need to reduce carbon emissions and ensure heritage and historic buildings are valuable contributors to the community they serve.
“There is debate amongst experts between the macro-scale need to reduce energy use and increase liveability and the micro-scale goal to protect the historic building’s authenticity,” Rachel says.
Rachel’s interviews have been recently completed and she is now developing best practice policy guidelines to inform the construction, design, and government sectors in New Zealand. She will engage Heritage New Zealand Pouhere Taonga and conservation professionals to shape these specific local guidelines.
She notes, “Historic buildings should not be exempt from energy efficiency requirements, but policies should allow flexible targets, even if these are achieved through little-by-little improvements.
"Warmer and drier environments are possible through sensible changes that will noticeably enhance the environmental and liveability factors of historic buildings.”
Rachel Paschoalin is a candidate in the Wellington Faculty of Architecture and Design Innovation under the supervision of Dr Nigel Isaacs and Dr Fabricio Chicca.
You can contact Rachel on rachel.paschoalin@vuw.ac.nz or Dr Nigel Isaacs on nigel.isaacs@vuw.ac.nz.