Regardless of your stance on the topic, there’s an undeniable “what-if” observed in the challenge of climate change. The case is no different for the construction-minded—if anything, there is a greater awareness of shifting standards to uphold safety despite weather extremes. A great guest post surfaced on Constructonomics around the subject and its implications on commercial construction. The following are some confrontations they mention, along with my additions on how these areas can be addressed head on. With new legislation protecting builders from making dangerous choices, there is ample protection, but still concerns for safety as risks grow.
The comfortable indoor temperatures we enjoy in a heat wave can be just as damaging to a building as the bitter cold elements in winter. Energy efficient air conditioning systems involve a high level of thermal insulation. Building durability is directly affected by thermal insulation increases, as the rate of building enclosure drying decreases and the moisture balance is affected. In the winter, buildings can struggle just as much. Heavy ice and snow formations gather and are prone to take a toll on roofs, ventilation, ductwork, and thermal barriers. I’ve heard of structures coined “Russian Sky Domes” designed to withstand extreme weights of snow and ice per meter. For those who battle extreme winter weather, the round shape of these unique buildings can prevent long-term snow laying and lead to more economical heating bills.
To lessen the impact of these conditions for those with more traditional buildings, Building Science emphasizes the discipline of understanding what materials and techniques work hardest for property owners:
“All materials and layers in a building assembly have some resistance to heat flow. However, some materials with a k-value lower than about 0.05 to 0.07 W / m ∙ K are deliberately used in building assemblies for their ability to slow the flow of heat. These building products are called thermal insulations. Insulations are usually solid materials (so-called body insulation), but radiant barriers that control only radiation heat transfer across air spaces are also available.”
What this translates to in building design and planning stages is a recognition that high strength/high density material is key. When there is a drop in density, there is a direct reduction in structural capacity. When materials are more porous, there is more room for heat transfer and less temperature regulation. This is appropriate in certain settings with a combination of porous insulation to allow air circulation where needed. Through the use of the proper materials and installation techniques catered to the climate, there is sufficient strength and more fitting heat flow.
When a building is constructed in a special flood hazard area (SFHAs), FEMA (Federal Insurance and Mitigation Administration) has comprehensive flood protection measures that cater to vulnerable regions (and even those not categorized as ‘dangerous’ from a flooding perspective). There are class descriptions of materials that are differentiated by class (levels 1-5), in which 1-3 is considered unacceptable and 4-5 acceptable. The best-case scenario, class 5, has a description that these materials are “Highly resistant to floodwater damage, including damage caused by moving water. These materials can survive wetting and drying and may be successfully cleaned after a flood to render them free of most harmful pollutants. Materials in this class are permitted for partially enclosed or outside uses with essentially unmitigated flood exposure.”
As for the other end of the spectrum, class 1 illustrates the explanation: “Not resistant to clean water damage or moisture damage. Materials in this class are used in spaces with conditions of complete dryness. These materials cannot survive the wetting and drying associated with floods.”
Whether flooring, walls, or ceilings, a good rule of thumb is any material that is absorbent is a no-go.
High Wind Endurance
I researched a good amount of indestructible homes to find one common denominator: concrete.
Joe Nasvik of Concrete Construction points out that “Creating continuous load paths between roof rafters and footings is very important if a house is to remain intact in a high wind event. It’s more difficult and expensive to do this for a wood-built home than a concrete one. Most concrete homes in the United States have pitched wood truss roofs so the critical connection hardware is between the exterior walls and the roof joists.”
In areas such as Florida susceptible to wind and seismic events, most construction is integrating these standards in coordination with the design wind speed guidelines in building codes.
Note: While the presence of climate change is debatable, extreme weather and vast changes in climate around the world are a reality of our current times when compared to historical weather data. While the exact cause of these changes in weather are unclear and subject of huge debate, the changes required in construction means and methods in order to adapt and successfully work in these new conditions are black and white.