
#12 - Condensation, Roof Ventilation and Building Science with Clarence Macalister
The Building Sciology PoddieShow Notes
This is the longest episode yet, but it’s worth every minute! In this episode of the Building Sciology Poddie, I interview Clarence Macalister, a builder and scientist with extensive experience in remediation and condensation management. In our chat we go deep into problems created by moisture and also into roof ventilation, finally an explanation!! We chat about the nuances of Passivhaus design, the role of sensors in monitoring building conditions, and share case studies of building failures. Clarence has a huge amount of practical skill and experience we can all learn, from so tune in and put any questions or feedback in the comments!
Show notes can be found here
More from The Building Sciology Poddie
In this eye-opening episode, host Jess Kismet speaks with Plum Stone, founder of the Safer Air Project, who brings a health policy and lived-experience lens to indoor air quality. Plum redefines clean air as a fundamental accessibility and equity issue, exposing the severe health impacts that poor indoor environments have on vulnerable populations in schools and workplaces. From classroom CO2 spikes to national performance standards, this discussion highlights why we must stop treating clean air as an afterthought and start engineering safer shared spaces for everyone.
Fresh off the AIRAH Indoor Air Quality Conference in Cairns, host Jess Kismet sits down with building science expert Sean Maxwell to unpack essential insights on ventilation, enclosure physics, and moisture control. Together, they discuss wisdom from industry legend Joe Lstiburek, why immediate regulatory action on continuous apartment ventilation beats waiting for perfection, and the necessity of external continuous insulation to protect building envelopes. The conversation challenges traditional HVAC design habits by demonstrating why outdoor air isn't always clean air and advocating for mechanical systems engineered around dew point targets rather than temperature alone.
Mechanical engineer Sonia Holzheimer joins host Jess Kismet to explore why designing HVAC systems for tropical climates like Far North Queensland requires a completely different playbook than standard southern building codes. Sonia breaks down the crucial differences between air conditioning and true dehumidification, revealing how modern inverter technology and energy-efficiency measures can inadvertently lead to severe indoor moisture traps and mould. From advocating for indoor dew point regulation over dry bulb temperature to inspiring the next generation through her project Cool Engineers, this episode offers a vital deep dive into the realities of tropical building science.
In this episode of the Building Sciology Poddie, host Jess Kismet sits down with Alex Kessler, translational scientist and founder of The Healthy Home Guide. After developing severe Chronic Inflammatory Response Syndrome (CIRS) from toxic mould exposure in his own home, Alex turned his scientific background toward environmental consulting to help others navigate complex chronic illnesses, allergies, and indoor air pollution. Alex breaks down common misconceptions around standard HEPA filtration, explains why high clean air delivery rates (CADR) matter more than standard efficiency percentages, and introduces the benefits of MERV-13 filtration. The conversation covers how to accurately monitor indoor air quality, affordable DIY fresh-air ventilation options for renters, and proper small particle cleaning techniques that avoid triggering toxic mould defenses. What we cover in this episode: Prioritize CADR over HEPA ratings: High-airflow MERV-13 filters drop room particle levels faster, quieter, and with less energy than restrictive H13 HEPA units.
Ben Walsham (founder of Arkata) returns to the show to unpack the chaotic rollout of NCC 2025, the reality of high-performance design in volume building, and why building physics hit differently in tropical climates. From AI-driven workflow automation to deep-dive window frame science, this episode cuts through regulatory confusion to focus on building healthier, higher-performing homes.