Designers have to step up when it comes to warmer, drier and healthier homes – with Peter Raimondo

Peter Raimondo is a senior Building Enclosure Engineer and podcaster at Oculus Architectural Engineering. We caught up with him to discuss his passion for developing warm, dry, and healthy buildings. 

Peter Raimondo

Peter, tell us a bit about yourself?  

I was born and raised in Toronto, Canada and studied civil engineering at the University of Toronto where I specialised in building science and construction. Following graduation, I worked in construction, travelled around Europe, and did other odd jobs until deciding to begin a career in forensic engineering. The job involved investigating why some buildings burnt down, why others had significant flooding issues and then figuring out how to fix the problems. Most recently, I spent time with RJC, a building science engineering consultancy, where I investigated why older buildings were having leaks and condensation issues and designed ways to fix those issues at the source. 

How can we change the way we construct buildings to improve health outcomes? 

Buildings in the late 1800s and early 1900s were constructed in a style that technically worked because they were built on trial and error, but the living conditions in those buildings weren't very comfortable. It seems we haven't moved too far from that in New Zealand, whereas many other countries have moved away from that construction philosophy.  

There is definitely a chance to improve the health of New Zealanders by constructing buildings that create a healthy indoor environment throughout the whole day.  

Right now, most buildings in New Zealand aren't heated to a comfortable and consistent temperature throughout the entire year, because they're not insulated enough to do that economically. Most people turn on the heat to create warm living conditions while they are at home in the evening, but then let the house cool down overnight or when they are away, which creates conditions to create condensation and then mould. Building houses with proper ventilation, insulation and heating helps prevent the development of mould (a cause of asthma) and condensation that contributes to rot and mildew, which can cause health and building issues. 

Why has New Zealand missed the boat on making healthy homes changes? 

When you look around the world, countries that are considered to have a warmer and more temperate climate have not always developed building legislation that mandates the construction of healthier homes.  

In my home city of Toronto, the temperature can fall to minus 40 in the winter and rises to plus 40 in the summer. These temperature extremes create the potential for serious health issues if you don't have a building envelope that keeps the interior space at a constant temperature all year round. Unfortunately, building codes generally only change in response to significant disasters where people die, or buildings collapse. It seems our temperate climate is causing an apathy where people won't accept that buildings can, or need, to be built to a higher standard than they are at the moment. Given that temperate climate, I believe it is an easy and cost-effective change to design buildings that maintain a constant temperature all year round. 

What fundamental changes are required to design heathier buildings?  

In my mind, the changes are small and incremental. But, it's a big step up from what we are doing at the moment. 

Right now, the building code allows you to design houses that don't have any ventilation. You can use your windows as ventilation even if you're not opening them. It also ignores the fact that people close their windows during the winter to stay warm.  

Secondly, there is a lack of heat in many of our homes. People either can't afford to heat their homes, or there is an attitude that is quite prevalent around New Zealand which says we heat when we are at home and turn off the heat when we are away. But since mould thrives when it has heat, moisture and a substrate to eat, this typical cycle of heating and cooling creates those exact conditions to help mould spread. Homes should be heated to between 18 and 25 degrees all day, all night, all year round. All walls should be insulated, and we should aim to get rid of our current style of aluminium windows. Most aluminium windows in New Zealand don't have thermal breaks which creates condensation.  

Why are we not installing aluminium windows that include thermal breaks? 

It's the standard at the moment in New Zealand.  

Aluminium windows without thermal breaks allow a large amount of heat to escape. All that is needed is the placement of a small piece of plastic inside the window joinery to improve the amount of heat retained in the building substantially.  

Many people are now installing double glazing, and while that helps heat retention, the edges of the windows continue to bleed heat. Thermally broken aluminium windows don't cost any extra in many countries, but they do in New Zealand because they aren't installed in large numbers.  

I aim to convince designers to include thermally broken aluminium windows in all buildings, which will help lower the price per unit. 

What's the role of designers in making these changes? 

I think designers have to step up and create buildings that are designed above our current code and designed to make sense. Currently designing to code doesn't necessarily mean that a building will be warm, dry and comfortable because of the loopholes I mentioned above. 

Has COVID-19 introduced any new challenges for the design of healthy buildings? 

I think COVID has brought some building problems to light.  

People are forced to work from home, and this has made them aware of just how uncomfortably hot or cold their house can become at different times of the day.  

When I was working from home during the COVID lockdown, I found that my feet were ice cold because the floor of the house is a concrete slab that sits above the garage. The other thing that has come to light is how viruses have a hard time surviving if the relative humidity of a room is between 40 and 60% at all times. So, if your house is super moist, say above 70% humidity, the virus has the conditions it requires to survive a little easier. Improving ventilation and reducing the amount of moisture in your home makes it more challenging for a virus to activate.  

Is changing our building code the first step to designing healthier buildings? 

Changing the code would be great, but we've been talking about that for decades, and it just keeps being put in the "too hard" basket. The code definitely needs to change, but I think it is time designers stop creating buildings that meet the basic, bare minimum standards.  

We need to design buildings that work well and based on the fundamentals; not on what we think will get through the council processes. Designers must consider how condensation and moisture will affect the building and look at installing mechanical ventilation as opposed to just having openable windows for air circulation.  

At the moment, heating systems don't have to be installed in buildings, but I would like to see that changed.  

So, there are the whole bunch of bits and bobs that could be improved, and if the industry begins to push in one direction, the building code will inevitably follow. However, I don't think the code will change to a point where we will have something that makes you say yes, "that is what's needed" anytime in the near future. 

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