4 Principles for Building a 100-Year Home How to build houses that contribute to the long-term health of the occupant and the planet.

As climate change continues to wreak havoc, more and more homebuyers are asking the right questions of their builders: Is this home capable of withstanding high winds and rain? Will it keep my family safe and healthy? How will it conserve energy and contribute to sustainability?

These questions are a call to action for homebuilders. We must endeavor to build homes that will not only withstand increasingly severe weather, but that have net zero energy consumption and zero carbon impact. I like to think of houses that meet these criteria as 100-year homes – because they are built to last and made with the long-term health of the occupant and planet in mind.

Here are four principles to guide every homebuilder in constructing 100-year homes.

1. Design for Occupant Comfort

Occupant comfort is paramount in longevity homebuilding. For an owner to be comfortable in their house, they must have uniform heating and cooling that manages both temperature and humidity. Comfort also goes hand in hand with safety and health.

To maximize occupant comfort, we must first choose the right sized HVAC systems. Smaller is often better, as oversized mechanicals tend to produce short cycling – causing the occupant to be too cold one minute, too hot the next, then too cold again. A proper HVAC system should also aim to keep relative humidity within 40% to 60%, which is optimal for preventing the proliferation of bacteria, viruses, fungi, and harmful chemical interactions.

Designing for occupant comfort also requires managing intermittent solar gains, which occur when a house's windows allow for excess heat by concentrating sunlight, not unlike the old schoolyard experiment where a magnifying glass creates a laser-like heat beam. Solar gains can be resolved with energy performance windows that have a low solar heat gain coefficient (or SHGC).

For all aspects of occupant comfort, it is important for the builder to manage decisions proactively without outsourcing them to others. This means not letting the décor consultant choose where the thermostat goes, and not waiting for performance issues before upgrading to the right heating and cooling system.

2. Improve the Indoor Air Quality of Homes

If the Covid-19 pandemic taught homebuilders anything, it is that houses are the last line of defense for human health. Our families face an increasing number of airborne threats, from pollution to viruses to dangerous chemicals. In fact, the EPA adds approximately 1,000 new chemicals to its registry every year, meaning we are now exposed to more chemicals in 30 days than our grandparents were in a lifetime.

Builders need to focus now more than ever on constructing airtight homes with proper ventilation systems. One way to increase airtightness is through AeroBarrier, a treatment process that seals homes in less than 3 hours to any level of airtightness. Proper sealing not only protects occupant health but also protects the environment by reducing a home's energy consumption by 15% to 20%.

Another key to indoor air quality is preventing off-gassing from paint and appliances. For example, electric stovetops and kitchen appliances lead to a dramatic improvement in air quality over gas-powered appliances, which emit high volumes of dangerous chemicals into the air. Indoor air monitors can also be installed in homes, giving the occupant the ability to check their air quality from their smartphone in real-time. Another example would be using a true Zero VOC paint such as Graphenstone, which also has no Formaldehyde or Methylisothiazolinone (MI) preservatives. These changes lead to better health, greater efficiency, and improved sustainability.

3. Climate Resilient Construction to Improve Resiliency

In you've followed the headlines, you might know that last year was the most active Atlantic hurricane season on record, this year is on track to be the worst west coast fire season in history, and an increasing number of dangerous tornados are churning across North America. Where I live In British Columbia, Canada, nearly 800 people died in 6 days this summer in the BC heat dome, which is approximately half the total who died there from Covid.

Homeowners may not consider these climate and weather factors until it is too late, which is why it is on homebuilders to prioritize climate resiliency in construction.

This starts with having a water management plan. As Dr. Joe Lstiburek says, "Rain is the single most important factor to control in constructing a durable structure." Builders must have a plan for draining the site with a slope grade away from the house, draining the ground with a foundation perimeter drain, draining the building with a proper roof system, and more.

If a roof fails in a tornado or a hurricane, the rest of the house is likely to fail with it. Fortunately, minor framing adjustments can make a big difference. A typical roof can be constructed to withstand an EF2 tornado with less than $1,000 of improvements. This can include truss-to-wall connections with a hurricane clip, or a 6-inch structural screw, to hold it all in place. These improvements are easy and low cost, and they could save lives.

4. Reduce Our Carbon Footprint, Including Embodied Carbon

To build a home that is truly environmentally sustainable, it is not enough to focus on energy efficiency. We must also focus on carbon reduction. This requires reducing the total lifecycle carbon footprint of a home—meaning the carbon from when it is built, as it is lived in, and as it ages in its environment.

The first factor to consider is the materials used. A large portion of a house's environmental impact comes from construction materials such as concrete, steel, and fiberglass, which emit large amounts of carbon. We must choose the cleanest materials possible, and then buy carbon offsets to make up for whatever carbon impact was unavoidable. Greener materials can also include a hybrid or all-electric HVAC system.

We should also begin, if we haven't already, our transitions to alternative power sources such as solar. Installation of solar panels on your roof can enable completely carbon neutral powering for the entire life of the home, and the cost is more than made up in the long-term by elimination of gas and electric bills.

It is time for the entire home building industry to adopt standards and practices for carbon-neutral building. My colleague at the Energy and Environmental Building Alliance (EEBA), Aaron Smith, recently wrote an excellent piece on how to go about this.

In our movement, all our efforts must complement each other. The more of us who build 100-year homes, the more homebuyers will demand that the above four principles apply to their homes too.

Those on the leading edge of this movement are not just building houses for the future, they are building the future of houses. A century from now, future generations will thank us for it.