Today’s modern air tight building envelopes are often constructed with moisture intolerant and vapour impermeable materials in a way that can trap moisture inside, leading to mold. This can present a health risk, building envelope failure, and/or a loss of structural integrity. BCIT’s School of Construction and the Environment states, “Building failures remain significant despite recent advances in building technology and adopting performance-based building codes.” (ref)
Oak Ridge National Laboratory is the largest US Department of Energy science and energy laboratory. They state the following about mold problems:
“Moisture causes billions of dollars of reported damage to building envelopes in North America each year.” Mositure – related damage not onl reduces the service life of buildings , but also influences the indoor air qulaity, the health and safety of the inhabitats, and the energy efficiency of walls, roofs, and foundations. If all of these additional influences are included in the estimate of actual damage, several tens of billion sof dollars in losses may be attributed to moisture-related damage in buildings every year.
Moisture is present in the air both inside and outside the building envelope and may be in the form of solid ice, liquid, or vapor. Moisture is driven through the building envelope by natural forces such as temperature, the partial vapor pressures (sometimes expressed in terms of relative humidity) on the inside and outside of the building, and the amount of liquid pressure (suction forces) caused by rain water, water leaks, or surface condensation.
…If moisture accumulates above a critical material-dependent threshold, the building components begin to rot, corrode, or otherwise degrade in structural or functional integrity…” (ref) The Eco Healthy Homes case study is prioritizing self drying, moisture tolerant building envelope solutions that are throughly investigated with computer modelling prior to construction so we can prevent future rot or mold problems.
“Disaster losses have doubled every five to ten years since the 1950s, and in 2005 they approached $100 billion worldwide.” (Canadian Institute for Catastrophic Loss Reduction)
Resilient Design works to develop resilience at the household, neighbourhood and community level. Resilience is the capacity to adapt to changing conditions and to maintain or regain functionality and vitality in the face of stress or disturbance. It is the capacity to bounce back after a disturbance or interruption.
City planners estimate that every dollar invested in enhanced resilience or disaster preparedness saves $4-5 in avoided repairs. Resilient design offers peace of mind and potentials savings as well. Through resilience we can maintain livable conditions in the event of natural disasters, loss of power, or other interruptions in normally available services or fuels. Relative to climate change, resilience involves adaptation to the wide range of regional and localized impacts that are expected with a warming planet: more intense storms, greater precipitation, coastal and valley flooding, longer and more severe droughts in some areas, wildfires, melting permafrost, warmer temperatures, and power outages.
Buildings are too seldom designed to prevent financial losses, health consequences or loss of life from the unexpected. Common approaches and building code fail to consider the potential of extreme weather events, service outages, moisture intrusion into the building envelope, infestation of pests (rodents, insects), structural shifts due to earthquakes, and more.
*Learn more about the importance of resilient design. and here.
“A study currently underway for the United Nations found that the economic cost of environmental damage by these top 3,000 companies is $2.2 trillion dollars, (or more than one-third of their profits if they were held financially accountable). Calculations include greenhouse gas emissions, other pollution, and water degradation but they are not exhaustive.(ref)
Encouraging the home building industry to turn towards locally reliant small businesses and practices that support life can transform the economic and manufacturing impacts of thousands of pounds of materials per house.
Barriers to deep green building
Deep green solutions are complex and expensive to implement in today’s building industry. For more please see : Barriers to deep green.