10 Passive House design tips for keeping cool in summer

The high temperatures this past summer have served to sharpen everyone’s focus on how to design Passive House buildings to remain comfortable for longer when the temps spike. The team at Sustainable Engineering Ltd is working on detailed energy modelling in order to produce building specification guidelines. We’ve also been thinking about what could be implemented right away: finding the …

Fine particulate pollution is terrible for human health

Today I learned that lymph nodes are heavily impacted by air pollution. This photo shows lymph nodes specifically associated with the lungs and how they are affected by air pollution as we age. It’s gruesome. I already knew fine particulates were bad, but this image has visceral impact and I’ll strengthen the advice I give to clients about how to …

Design Passive House for your individual client

Should Passive House designers be doing more to design buildings that avoid summer overheating? This article from mainstream business magazine Forbes considers Bahnstadt, a Passive House district in Heidelberg, Germany. The story quotes residents who were struggling to stay comfortable as summer temps soared in 2023.  The two residents have different motivations for living there and different experiences of their …

Morning Report: why are NZ homes so damn hot right now?

Morning Report rang me this week for comment about overheating homes, in the face of record temperature spikes. You can listen to the short segment here, or there’s a print version also. For the physics geeks, here is how I worked out the numbers I provided about emissions. I used an average grid emissions factor of 0.12 kgCO2e per kWh …

New free tool for exploring climate files

I’ve discovered a climate file exploration tool that will be really useful for Passive House designers. Best, it’s open source, so free to use. This is particularly timely given the promised update to the climate files we currently use for Passive House design in Aotearoa. What we currently access contains 30 years of climate data—but NIWA compiled those files 20 …

Replacement cycles should inform climate change mitigation policy

It’s curious there is so much public discussion about electric vehicles and why and how we should ‘flip the fleet’ … and so little about buildings. Yes, we need to move people and goods in far less polluting, carbon-intensive ways. But decarbonising buildings is even more urgent and the graph below shows why, in a compelling and easy-to-grasp way. Replacement …

Choose the right heat pump

Source: Coming in from the cold: Heat pump efficiency at low temperatures, Duncan Gibb et al. 2023 This graph from a recent European academic paper shows air-source heat pump performance in mild cold climates in Canada, China, Germany, Switzerland, the United States and the UK. The red dashed line showing average COP is not the important takeaway from this graph. …