Indoor air filtration capable of reducing PM2.5 particles increases life expectancy and experts argue should change standards to require better filtration. In general, the filters in ventilation equipment are primarily designed to protect the equipment and not to make the air better for those who breathe. There are exceptions, such as the F7 filters in the Passive House-level MVHR systems, …
Scotland sets example for new building performance
Commit to the outcome then work out how to get there, argues Andy Marlow, a leading Australian Passive House designer and former APHA board member. In a recent essay on The Fifth Estate, he highlights how the Scots decided all new builds needed to perform to the Passive House standard—before working how what it would cost or how to pay …
Australian homes aren’t warm either
Australia is much warmer than New Zealand but apparently not inside their homes in winter. This new study points out that 80% (!) of the Australian homes measured failed to meet WHO recommendations for minimum indoor temperatures. We know from our own issues here in New Zealand that cold equals mould and poor health. The problem of cold homes isn’t …
Economic benefits to extensive housing retrofits
Large-scale retrofit programmes to improve New Zealand housing would generate huge benefits, according to a recent report by BERL: $50 billion in health and energy savings and over $116 billion in broader well-being benefits, depending on the level of investment in retrofitting homes. The report examined international retrofit projects and investigated the economic impacts of a large scale programme. Three …
Embodied carbon tools from NZ Green Building Council
The NZ Green Building Council undertook detailed consultation into what its clients needed to assess embodied carbon. It has released a suite of tools to assist with measuring, verifying and comparing embodied emissions in new buildings and major refurbishments. “The built environment, including infrastructure, contributes 20% of New Zealand’s emissions,” it notes on the release page. “Reducing embodied carbon is …
Q&A with Jason: explain heating load vs demand
Q. What is the difference between heating demand and heating load and how is each measured? How do these numbers impact on Passive House certification? A. Both these numbers are important. Passive House certification sets an upper limit for both these metrics: breach both and you’ll miss out on certification. However, the point of measuring these two things is to …
“The most sustainable house is the one you don’t build”
New Zealanders have a vast job ahead retrofitting existing housing stock. Massively improving the thermal performance and energy efficiency of existing residential buildings is not optional if we are to meet our carbon emissions reduction commitments. Work in progress by architect and Passive House designer Murray Robertson is highlighting the feasibility of deep retrofits to particular types of New Zealand …
Owners loving Bushland Park’s first Passive House homes
Bushland Park set out to be New Zealand’s first Passive House subdivision and builders Ethos Homes boldly built the first two homes on spec. The build went smoothly but the two homes’ auction date coincided with a stalled housing market and a glut of ordinary but shiny homes coming up for sale in Christchurch. Since then, house prices have fallen …
Is natural plaster airtight?
UPDATE Aug 2023 This project’s final blower door test showed a significant improvement in airtightness, which qualifies the initial commentary made below at the time of the preliminary test. The final result is 0.32 ACH. The project team attribute the improvement largely to the completion of the second layer of plaster. A repair to a tiny air leak in one …