Update: A National Building Code committee reviewing radon has determined radon maps are incapable of accurately identifying radon risk.
“A Health Canada study in 2011 showed that there are no areas of Canada that are radon free (the data resulting from this study is provided in the form of maps in Annex J for reference). However, indoor radon gas
concentrations cannot be predicted prior to construction and it is important to emphasize that individual buildings can have different indoor radon concentrations even though they are built in the same zone as indicated on the maps.”
They are recommending mandatory radon mitigation for new housing across Canada. Their studies show more energy efficient homes boost radon levels.
The BC government launched the BC Step Code in 2017 without any due diligence on radon, now being done by Codes Canada. Municipalities like Saanich, Victoria, North Saanich, Central Saanich, Colwood and others are boosting energy efficiency via the BC Step Code, undermining health & safety. This is why research and education must come first before changes to the building code.
Latest Update: Here is a recent radon study in Halifax revealing the following:
Radon levels in homes built following the 2010 National Building Code have not decreased. In fact, more homes built in 2012 to 2021 (67%) are above the 200 Bq/m3 level than homes built in 2001 to 2010 (56%).
- 33% of homes built in 2012 to 2021 had radon levels below 200 Bq/m3 compared to 44% of those built in 2001 to 2010
- the percentage of homes with radon levels in the 200 to 600 Bq/m3 range is similar at 42% (2001 to 2010) and 40% (2012 to 2021)
- almost twice as many homes built in 2012 to 2021 (27%) had radon levels above 600 Bq/m3 compared to homes built in 2001 to 2010 (14%)
Scientific studies have identified several factors associated with higher radon levels in newer homes:
- size of the building
- quality of the sealing of the radon barrier under the slab
- air tightness of doors and windows (energy-efficiency measures (Step Code)
The results also indicate that the radon gas barrier may not be enough to reduce radon levels in new homes in some areas. This supports the need to improve and strengthen radon control measures in future building codes.
There is “A trend of increasing indoor radon in housing…
There is no safe level of radon, and the excess relative risk of radon increases linearly with the cumulative radon exposure. There is a health benefit from reducing any concentration of indoor radon, lowering the risk of lung cancer for both smokers and non-smokers, which is proportional to the reduction in cumulative or long-term radon exposure.
Canadian radon mapping is not accurate enough
Lung cancer is the leading cause of cancer death in Canada (26%)
Radon is the second cause of lung cancer, after smoking
Radon can seep into housing through cracks and joints in the floor and walls when the pressure is lower indoors than in the soil (depressurization in more energy efficient homes)
Passive radon stacks reduce indoor radon very effectively
Installing passive radon stacks in new housing construction shows that the main benefit is preventing lung cancer deaths
Reduces risk of lung cancer for both smokers and non-smokers
Reduces the main cause of lung cancer in non-smoking household
“The Task Group on Radon and Soil Gas Mitigation (TG) is recommending that the National Building Code mandate the addition of a passive radon stack system to all Part 9 dwelling units containing residential occupancies that are in contact with the ground.”
More missteps with the BC Step Code:
We learned the following at a conference by the Canadian Association of Radon Scientists and Technicians:
- Radon is site-specific and every home should be tested. Contrary to BC’s radon map, there are no safe regions for radon.
- New homes should be tested right after construction and again two years later due to concrete settling and shrinkage.
- Radon levels double in retrofits with the greatest impact from double-glazed windows.
- In addition to lung cancer, radon is linked to lymphoma, myeloma and leukemia. Leukemia is the type of cancer most often found in children.
- Canada’s radon maximum of 200 bq is likely unsafe over the long-term, especially for children. The World Health Organization’s maximum is 100 bq.
- Even low radon areas add to lung cancer risk when homes are occupied by smokers.
- Very air-tight homes lacking sufficient ventilation are showing higher radon levels.
The BC government launched their energy efficient Step Code prior to a radon review only recently underway by the National Building Code.
Municipal councils with little or no knowledge of these issues are implementing the BC Step Code through their local bylaws.
It is another recipe for potentially harmful unintended consequences and undermines health and safety in BC’s Building Code.
Update: Recently, another misstep has occurred with BC’s Step Code. New data reveal Tier 5/Net Zero-ready homes, producing as much energy as they use, are achievable at Tier 4.
In other words, Tier 5 is unnecessary for Net Zero-ready, yet Victoria and some lower mainland municipalities are already fast-tracking Tier 5.
Homebuyers will be overpaying tens of thousands of dollars for Tier 5 homes required by their municipalities thinking Tier 5 is the only path to Net Zero-ready..
BC already has the highest home prices in Canada – now rising higher because the province circumvented the National Building Code process with a deeply flawed BC Step Code.
The BC govt’s initial claims that BC Energy Step Code would be “voluntary” for municipalities has been short-lived. The govt plans to make the costly Step Code 3 mandatory in 2022.
The reason is many municipalities rejected the govt’s claims of affordability combined with concerns about unintended consequences such as toxic radon.
The National Building Code committee is reviewing energy efficiency, doing a radon study and plans to introduce new energy efficiency standards by the end of 2021, including prescriptive options not available in the BC Step Code.
The BC govt’s decision to make their own code mandatory is clearly a move to circumvent the National Code, ironically, with whom BC has a harmonization agreement. Apparently, it’s not worth the paper it’s written on. The same can be said for BC’s radon map, shown to be entirely unreliable. Radon is site specific and high counts are evident in allegedly low radon areas. The rumour mill is the BC govt plans to require radon mitigation rough-ins throughout the province, yet they continue to promote the BC Step Code without mandatory mitigation in many regions. Studies show higher radon levels in more energy efficient homes without mitigation, and radon is the second biggest cause of lung cancer and rising in Canada. Here is another update on Step Code and radon.
Here is a story about a Salt Spring family discovering high levels of radon.
UPDATE: The province estimated added costs of $3,945 for Tier 3, however, an experienced VRBA Built Green Builder completed an estimate of $28,000 not including overhead. This was the lowest cost option modeled by a Certified Energy Advisor.
Municipalities are considering adopting the province’s Step Code, yet many do not understand the implications:
- Step Code is actually a Leap Code. While the name implies energy efficiency is achieved in steps, in fact, municipalities may leap into any Tier and invoke very high levels of energy efficiency (1 – 5 Tiers ) without certified education, affordability or proven practice. This was done in West Vancouver, leaping into Tier 3 to start and Saanich bypassed Tier 2, going from Tier 1 to Tier 3 within 7 months. Sooke is considering leaping directly into Tier 3.
- Step Code does not effectively address climate change. There is a reduction of only 1 or 2 air changes per hour (GHGs) in new, already energy efficient homes. Renovation of older homes through a renovation tax credit can save as much as 40 air changes.
- Step Code violates BC’s agreement to harmonize the provincial building code with Canada’s national code. National diligence is ignored, undermining consumer protection. For example, NRCan recently discovered flawed metrics in BC’s Step Code. In addition, a BC scientist has discovered high levels of radon gas may be prevalent in North Shore municipalities, yet these municipalities already started on Tier 3 of the Step Code without this knowledge. Here is a story about a Salt Spring family discovering high levels of radon in their home. Homes with radon gas exposure need special venting, especially if they are very tight energy efficient structures like Step Code. High levels of radon were only recently established in Duncan indicating the BC govt’s radon map is often inaccurate and radon can be site specific. Radon gas is linked to lung cancer and tightening homes without attention to radon mitigation may result in tragic unintended consequences. This demonstrates why municipalities are not qualified to invoke code standards outside of the National Building Code process.
- The BC govt’s estimates are too low. The govt says a Tier 5 (Passive Home) is only $17,450 more to build. Our survey of Built Green/Passive Home builders indicates costs of at least $55,000 to $110,000. UPDATE: The province estimated added costs of $3,945 for Tier 3, however, an experienced VRBA Built Green Builder completed an estimate of $28,000 not including overhead. This was the lowest cost option modeled by a Certified Energy Advisor. Here is our letter sent to municipalities in Greater Victoria. Saanich, Oak Bay, Victoria and North Saanich that have fast-tracked the Step Code which adds significant costs and may result in unintended consequences. Langford, where 40% of all new homes are constructed, and many other municipalities are wisely awaiting changes in the National Building Code.
- Step Code has no certified education program. Built Green/Passive Home programs have certified education to avoid unintended consequences like leaky condo.
- Step Code enforcement is a significant responsibility for municipal taxpayers. The Municipal Insurance Association says “Building bylaws are one of local governments’ greatest exposures to liability risks.” Municipal taxpayers may end up paying for their councils’ poor judgment. The City of Delta discovered this when ordered by a judge to pay $3 million in a leaky condo lawsuit in 2001.
- One of the most challenging BC Step Code flaws is the foundational premise “The BC Energy Step Code does not specify how to construct a building, but identifies an energy-efficiency target that must be met and lets the designer/builder decide how to meet it.” A National Building Code Task Group, (diligence the BC govt circumvented), identified materials and applications that are appropriate for lower Tiers may be inappropriate for higher Tiers. For higher Tiers, building envelope failure may be accelerated using basic code materials and applications.
Fast-tracking energy efficiency is both irresponsible and costly. The Step Code is the wrong way to achieve more energy efficiency in new homes.
Instead, support Built Green’s affordability, education and proven practice, National code diligence, and a reno tax credit for older homes.
Show this column to your city councilors before they take a misstep by adopting the ill-advised BC Step Code.
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This column appears Wednesdays in the Times Colonist newspaper.