Many of our buildings are poorly ventilated, and that adds to COVID risks



ambimages/Shutterstock

Geoff Hanmer and Bruce Milthorpe, University of Technology Sydney

The virus that causes COVID-19 is much more likely to spread indoors rather than outdoors. Governments are right to encourage more outdoor dining and drinking, but it is important they also do everything they can to make indoor venues as safe as possible. Our recent monitoring of public buildings has shown many have poor ventilation.

Poor ventilation raises the risks of super-spreader events. The risk of catching COVID-19 indoors is 18.7 times higher than in the open air, according to the US Centers for Disease Control and Prevention.




Read more:
Poor ventilation may be adding to nursing homes’ COVID-19 risks


In the past month, we have measured air quality in a large number of public buildings. High carbon dioxide (CO₂) levels indicate poor ventilation. Multiple restaurants, two hotels, two major shopping centres, several university buildings, a pharmacy and a GP consulting suite had CO₂ levels well above best practice and also above the absolute maximum mandated in the National Construction Code.

Relative humidity readings of less than 40% associated with both heating and cooling air are also of concern. Evidence now suggests low humidity is associated with transmission.

If anyone had COVID-19 in these environments, particularly if people were in them for an extended period, as might happen at a restaurant or pub, there would be a risk of a super-spreader event. Less than 20% of individuals produce over 80% of infections.




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Many aged-care deaths were connected

It appears a relatively small number of super-spreader events, probably associated with airborne transmission of SARS-CoV-2, the virus that causes COVID-19, were responsible for most of the deaths in Victorian aged-care facilities.

Of the 907 people who have died of COVID-19 in Australia, 746, or 82% of COVID-19 deaths, were associated with aged care. In Victoria, there were 52 facilities with more than 20 infections. Three had over 200 infections. As a result, 639 of the 646 aged care residents who died in Victoria were located in just 52 facilities.

But official advice hasn’t changed

Aged-care operators and the states based their infection control on the advice of the Commonwealth Infection Control Expert Group (ICEG). As of September 6, the Coronavirus (COVID-19) Residential Aged Care Facilities Plan for Victoria stated:

Coronavirus (COVID-19) is transmitted via droplets, after exposure to contaminated surfaces or after close contact with an infected person (without using appropriate PPE). Airborne spread has not been reported [our emphasis] but could occur during certain aerosol-generating procedures (medical procedures which are not usually conducted in RACF). […] Respiratory hygiene and cough etiquette, hand hygiene and regular cleaning of surfaces are paramount to preventing transmission.

In early August, more than 3,000 health workers had signed a letter of no confidence in ICEG. The letter noted that aerosol transmission was causing infections in medical staff, many of whom worked in aged-care facilities.

On September 7, we wrote to the federal aged care minister, Richard Colbeck, drawing attention to our August 20 article in The Conversation, which referenced a July 8 article in Nature. The Nature article identified an emerging consensus that aerosol transmission of SARS-CoV-2 is probable in low-ventilation environments.




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The director of the Aged Care COVID-19 Measures Implementation Branch wrote back on Colbeck’s behalf on September 28 saying:

Current evidence suggests COVID-19 most commonly spreads from close contact with someone who is infectious. It can also spread from touching a surface that has recently been contaminated with the respiratory droplets (cough or sneeze) of an infected person and then touching your eyes, nose or mouth.

In other words, Commonwealth authorities were still playing down the significance of airborne transmission nearly two months after the letter of no confidence was sent to ICEG and three months after the article in Nature. By the end of September, Victorian aged-care facilities had reported over 4,000 cases of COVID-19, about half of them in staff.

On October 23, ICEG was still saying:

There is little clinical or epidemiological evidence of significant transmission of SARS-CoV-2 (the virus that causes COVID-19) by aerosols.

Focus on the ‘3 Vs’ to reduce risks

The key thing we need to do until a vaccine is rolled out is to try to prevent indoor super-spreader events. According to the University of Nebraska Medical Centre, we should remember the “three Vs” that super-spreader events have in common:

Venue: multiple people indoors, where social distancing is often harder

Ventilation: staying in one place with limited fresh air

Vocalization: lots of talking, yelling or singing, which can aerosolize the virus.

Measuring indoor ventilation is quick and easy using a carbon dioxide detector. Any CO₂ reading of over 800 parts per million is a cause for concern – the level for air outside is just over 400ppm.

There is no excuse for governments, health authorities and building owners not to monitor ventilation levels to help ensure members of the public are as safe as is reasonably practicable when indoors.

There is also no excuse for the Australian Building Control Board not to change the National Construction Code to require fall-back mechanical ventilation systems be fitted and CO₂ and humidity monitored in all buildings frequented by the public, particularly aged-care facilities.

With the knowledge we have now and a low rate of community infection, Australia should be able to make it through to vaccine roll-out with relatively few further infections and deaths. But that depends on being vigilant about the quality of ventilation indoors and the associated possibility of super-spreader events. This is especially important in aged-care facilities and quarantine hotels.

It’s probably a good idea for us all to open the windows and let the fresh air in.The Conversation

Geoff Hanmer, Adjunct Professor of Architecture and Bruce Milthorpe, Emeritus Professor, Faculty of Science, University of Technology Sydney

This article is republished from The Conversation under a Creative Commons license. Read the original article.

The coronavirus pandemic might make buildings sick, too



Discolored water can be caused by heavy metals, such as iron or copper. Iron can also act as a nutrient for organisms to grow in the pipes.
Kyungyeon Ra/Purdue University, CC BY-ND

Caitlin R. Proctor, Purdue University; Andrew J. Whelton, Purdue University, and William Rhoads, Virginia Tech

While millions of people are under orders to stay home amid the coronavirus pandemic, water is sitting in the pipes of empty office buildings and gyms, getting old and potentially dangerous.

When water isn’t flowing, organisms and chemicals can build up in the plumbing. It can happen in underused gyms, office buildings, schools, shopping malls and other facilities. These organisms and chemicals can reach unsafe levels when water sits in water pipes for just a few days. But, what happens when water sits for weeks or months?

There are no long-term studies of the risks and only minimal guidance to help building owners prepare their water for use again after a long shutdown.

As researchers involved in building water safety, we study these risks and advise building owners and public officials on actions they can take to reduce the potential for widespread waterborne disease. A new paper highlights these issues and our concerns that the COVID-19 stay-at-home orders may increase the chance of harmful water exposure when people return.

What happens when water gets old?

Just like food that sits in a refrigerator for too long, water that sits in a building’s pipes for too long can make people sick.

Harmful organisms, like the bacteria that cause Legionnaire’s disease, can grow. If not maintained, devices like filters, water tanks, heaters and softeners can become organism incubators.

With certain pipe materials, water can accumulate unsafe levels of lead and copper, which can cause learning disabilities, cardiovascular effects, nausea and diarrhea.

Copper can leach from plumbing pipes and valves, as it did in this hotel bathtub. Ingesting water with high levels of copper can cause illnesses.
Andrew Whelton, CC BY-ND

Drinking this water is a problem, but infections can also result from inhaling harmful organisms. This occurs when water splashes and becomes an aerosol, as can happen in showers, hot tubs and pools and when flushing toilets or washing hands. Some of these organisms can cause pneumonia-like diseases, especially in people who have weakened immune systems.

Water inside a building does not have an expiration date: Problems can develop within days at individual faucets, and all buildings with low water use are at risk.

Keep the water flowing

To avoid water issues, “fresh” water must regularly flow to a building’s faucets. Most U.S. water providers add a chemical disinfectant to the water they deliver to kill organisms, but this chemical disappears over time.

Medical facilities, with their vulnerable populations, are required to have a building water safety plan to keep water fresh and prevent growth. Schools, which have long periods of low use during the summer, are advised to keep water fresh to reduce water’s lead levels.

Health agencies in the U.S., Canada, England, Europe and some states have released recommendations in recent weeks, advising that building water be kept fresh during COVID-19 stay-at-home orders. There’s some debate over the best way to do that, but the core message is the same: Do not let water sit in buildings.

Flushing accomplishes several goals. Caitlin Proctor/Purdue University.

If water isn’t being used in a building, intentionally flushing the building to replace all the old water with new water can be done at least weekly. It also helps remove sediments that accumulate along pipe walls.

Faucets, water heaters and softeners, appliances such as refrigerators, toilets and other water systems, including cooling towers, all need to have water turnover. Some of these can require specialized attention. Faucet aerators should be removed because they accumulate materials and slow down the flow.

How long flushing takes depends on the building’s piping design, devices and the speed of water exiting the faucets. All buildings are different.

It took more than 80 minutes of flushing to draw fresh water to the farthest faucet of one 10,000-square-foot building. In another building, it took 60 minutes just to get fresh water from the water meter to the basement of a building 30 feet from the street. A single large building may take hours or days to clear.

Easier to avoid contamination than clean it up

For building managers who haven’t been running the water during the pandemic, the water sitting in pipes may already have significant problems. To perform flushing, safety equipment, including masks, currently in short supply, might be needed to protect workers.

A slow “ramp-up” of the economy means buildings will not reach normal water use for some time. These buildings may need flushing again and again.

Shock disinfection, adding a high level of disinfectant chemical to the plumbing to kill organisms living in it, may also be necessary. This is required for new buildings and is sometimes done when water in new buildings sits still for too long.

Cut-open shower pipes reveal a biofilm with metal deposits.
Caitlin Proctor/Purdue University, CC BY-ND

Inexpensive chemical disinfectant tests can help determine if the water is “fresh.” Testing for harmful organisms is recommended by some organizations. It can take several days and requires expertise to interpret results. Metals testing might be needed, too. Public health departments can provide specific recommendations for all of these actions and communication of risks.

The need for standards and water safety

Water left sitting in the pipes of buildings can present serious health risks.

Standards are lacking and very much needed for restarting plumbing and ensuring continued water safety after the pandemic passes.

Right now, building managers can take immediate action to prevent people from becoming sick when they return.

[You need to understand the coronavirus pandemic, and we can help. Read The Conversation’s newsletter.]The Conversation

Caitlin R. Proctor, Lillian Gilbreth Postdoctoral Fellow, Purdue University; Andrew J. Whelton, Associate Professor of Civil, Environmental & Ecological Engineering, Purdue University, and William Rhoads, Research Scientist, Virginia Tech

This article is republished from The Conversation under a Creative Commons license. Read the original article.

How ‘Earthships’ could make rebuilding safer in bushfire zones



Earthship Ironbark, Author provided

Martin Freney, University of South Australia

Recent disastrous bushfires have rebooted debate about how to (re)build in the Australian bush. Questions are being asked about building standards, whether a fire-proof home is possible, the value of fire bunkers when it’s too late to leave, and if we should even live in the bush any more.

I suggest homes and community buildings in bushfire-prone areas can be made much more fire-resistant, perhaps even fire-proof, by adopting earth-covered, off-grid structures – known as Earthships – as the new standard.




Read more:
Before we rush to rebuild after fires, we need to think about where and how


Built for survival

Houses sheltered by earth have a higher chance of survival in a bushfire. This is because earth-based constructions are non-flammable (while topsoil can burn and smoulder, clayey, sandy and gravelly soil does not).

A typical Earthship design has double-glazed windows to the north to let in winter sun, while mounds of earth, pushed up to roof level, protect the south, east and west walls. Taking this a step further, an earth-covered house includes a layer of earth over the roof.

The north-facing double-glazed windows (an essential element of passive solar design) is the only part of the building that needs some other protection.

Bushfire building codes and standards already demand that windows have extra-thick, toughened glass to resist burning debris and intense heat. Double glazing (two layers of glass separated by a small air gap) offers extra protection. In very high-risk areas, bushfire shutters are a requirement.

Although not demanded by building codes, automated sprinklers could be used to spray water on the windows. But automated systems are problematic during a bushfire when power and water supplies are likely to fail.




Read more:
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Independent water supplies (big water tanks) and pumps (usually petrol or diesel) are often a condition of approval for new homes in fire-prone areas. However, these are difficult to automate because of choke, throttle, ignition and refuelling issues.

Examples around Australia

Enter the Earthship. Invented by American architect Michael Reynolds, thousands have been built all over the world, often by owner-builders.

Earthships, invented by Michael Reynolds, are now found all over the world.

I built Australia’s first council-approved Earthship – Earthship Ironbank – in the bushfire-prone Adelaide hills. Australian examples can be found in all states, including at Ironbank in South Australia, Kinglake in Victoria, East Augusta and Jurien Bay in Western Australia, and Narara and Marulan in New South Wales.

Earthships have an electric pump powered by solar panels and a battery for day-to-day water supply – and to fight fires. Sprinklers can then spray water on any vulnerable areas regardless of grid failures and without needing to deal with the flammable fuel that petrol and diesel pumps require.

The standard Earthship design has another feature that could save lives. Underground pipes called earth-tubes or cooling tubes bring fresh air into the building at a nice temperature (better than outside) due to the heat-exchanging effect of the earth around the pipes. When wet fabric is placed over the end of the pipes, these can filter out bushfire smoke.

Earth-covered homes are very air-tight, which combined with the earth-tubes helps keep out smoke and reduce asphyxiation risks.

Another defence mechanism is the “greenhouse”, a sunroom and corridor space on the sunny north side used for passive heating and cooling, treating wastewater and growing food. Yet another layer of double glazing isolates the greenhouse from the living spaces behind it. Adding indoor sprinklers (commonplace in commercial buildings) to the greenhouse could create a “wet buffer zone” and stop embers blowing into living areas where flammable furnishings are a hazard.

An iconic Earthship feature is the tyres used to form the exterior earth walls. While empty tyres are highly flammable, in this design they are not. The tyres are filled with compacted earth and protected by a layer of earth many metres thick (inside walls are rendered). There is already evidence of their fire-resistant nature.




Read more:
Australian building codes don’t expect houses to be fire-proof – and that’s by design


Safer for the planet too

My PhD research focused on the energy efficiency and environmental footprint of the Earthship, comparing it to other construction systems and designs.

A look at the author’s Earthship Ironbark.

Earth is a low-cost, readily available material. It takes very little energy to dig it up, needs no processing and minimal (if any) transport. It is difficult to think of a more sustainable, inexpensive and non-flammable material.

I found off-grid homes minimise their eco-footprint by kicking three very dirty habits: the power, water and sewage grids. “Earthy” construction methods, such as Earthship, rammed earth, mudbrick and strawbale, also have much lower environmental impacts.

Earth-covered buildings are renowned for their energy efficiency. Earth insulates and has “thermal mass”, an architectural term for dense materials (e.g. concrete, brick, rammed earth, water). Thermal mass evens out temperature changes by absorbing heat when it is too hot inside and releasing heat when it is too cold inside. This means minimal heating and cooling bills.

There are a few “tricks” to getting council approval. Hire an experienced structural engineer and use a private certifier or surveyor for building rules consent as they are better equipped to certify compliance with the National Construction Code. The one aspect of the Earthship I couldn’t get approved was an indoor greywater garden and toilet-flushing system.




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Parts of the roof are earth-covered with fire-fighting sprinklers on the roof and windows. If I was building again I’d prioritise bushfire resilience by making it fully earth-covered with fire shutters, sprinklers and a safe room.

Further study is needed to scientifically validate my proposal here. However, we already have some evidence that Earthships, with a few minor design changes, might be the most sustainable, liveable, economical, fire-resistant buildings ever conceived of.The Conversation

Martin Freney, Lecturer in Industrial and Sustainable Design, University of South Australia

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Before we rush to rebuild after fires, we need to think about where and how


Mark Maund, University of Newcastle; Kim Maund, University of Newcastle, and Thayaparan Gajendran, University of Newcastle

A primary school in East Gippsland was burnt down in the current bushfire crisis. While Premier Daniel Andrews immediately committed to rebuilding the school as it was, media reported the local CFA captain didn’t want it rebuilt.

Screen Shot from abc.net.au.
https://www.abc.net.au/news/2020-01-15/bushfire-destroys-clifton-creek-primary-school-gippsland/11860490

Public support for rebuilding in the same disaster affected places is often high. But as fire-fighting agencies are aware, our bushfires are increasing in size, intensity and duration, and a warming climate will continue to worsen these factors. We need to start being more strategic about where we rebuild homes and facilities lost to fire, and how.

Rush now, regret later

As there are sadly many people without homes and many businesses that have suffered lost income from reduced tourism and other activities, urgency in such a response seems reasonable.

But there’s a risk that rebuilding the same buildings in the same areas may not mitigate the current risks or any future risks under new climate scenarios – existing and new communities will be vulnerable. Planning can assist with managing future bushfire risks by helping decide where homes, buildings and infrastructure should be located.

Importantly, we must not rush to rebuild the same buildings in the same location. We need to consider risks from natural hazards in these bushfire prone areas such as ember attack, radiant heat, flammable building materials and safe evacuation routes.

If homes and some community buildings, such as schools, are located in areas that are too risky and likely to be lost in future bushfires then we need to consider our options. These may include changing the land use zoning to allow only lower-risk buildings (for industrial rather than residential use), or increasing building requirements for bushfire protection.

Before commencing rebuilding, planning agencies need to plan how communities can be made resilient and if there is opportunity to use the affected land for houses designed with the highest bushfire attack level or shops or offices with higher fire ratings.

Alternatively, planning agencies can choose to use cleared land adjacent to high bushfire risk as parks or roads to provide additional separation between buildings and vegetation.

Organisations involved in planning need to focus on increasing the separation between buildings and vegetation, as well as additional fire safety measures for buildings.

How to rebuild

We need to consider increased construction standards for buildings to better protect them against bushfires — things like fire resistant walls, thicker glass and metal screens for windows, non-combustible roofs and access to water to fight fires.

However these provide only some protection. Buildings may continue to be lost in future bushfires, so what we construct in these areas needs to be reconsidered.




Read more:
Australian building codes don’t expect houses to be fire-proof – and that’s by design


Options to rebuild in high risk areas should include buildings that are seen as low risk to human life and livelihoods such as storage or warehouse-style buildings and light industrial buildings. Owners of these buildings may need to accept they may be lost to bushfire.

Buildings that contain large numbers of people that need assistance during bushfires such as schools, aged care and hospitals should be located with extensive separation from bushfire risk, as well as with increased construction standards with multiple evacuation routes.

High-risk areas could be used as parks. This could also increase the separation between vegetation and dwellings.
from http://www.shutterstock.com

The speed and intensity of recent fires shows there may be less time to evacuate under existing and future disaster conditions, so continuing to build in high hazard prone areas may no longer be appropriate.

A new national planning policy should guide the states in considering the exposure of communities to these hazards and their capacity to respond, such as evacuation routes, distance to refuge centres and distance from fire services.

A national policy

Before we rush to rebuild our homes, roads and infrastructure we need to review planning policies and bushfire hazard maps produced by state fire services and have their involvement in future decision making around this area.

We need a national bushfire planning policy to address risk that crosses state boundaries and to provide a consistent approach to identifying where communities can locate and what activities can occur in high risk areas.The Conversation

Mark Maund, PhD Candidate, School of Architecture and Built Environment, University of Newcastle; Kim Maund, Discipline Head – Construction Management, School of Architecture and Built Environment, University of Newcastle, and Thayaparan Gajendran, Associate Professor, School of Architecture and Built Environment, University of Newcastle

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Australian building codes don’t expect houses to be fire-proof – and that’s by design


Raymond William Loveridge, University of Technology Sydney

More than 2,000 homes have been destroyed in Australia since the start of the bushfire season. More will certainly be destroyed before the season ends in March.

Could these houses have been built to better withstand fire?




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Quite probably. But that doesn’t necessarily mean Australia’s building regulations need reforming to ensure homes are made more fireproof.

Appropriate building codes are about weighing costs and benefits. Only analysing the reasons buildings were destroyed will tell us if more needs to be done.

Performances standards

Not all buildings are created equal. Newer buildings will generally be more fire-proof than older ones, due to building regulations having been improved over time.

In particular, national building requirements for residences in bushfire-prone areas were improved after the 2009 “Black Saturday” bushfires in Victoria, in which 173 people died and more 2,000 homes were destroyed.

Buildings are regulated by states and territories but governments have recognised the value of nationally consistent building codes through the National Construction Code. This code, among other things, sets minimum standards for the design and construction of new buildings on bushfire-prone land. (What land is deemed “bushfire prone” is defined by state and territory legislation.)

The National Construction Code is “performance-based”. It doesn’t specify how a building must be built, but how a building must perform. This means innovative designs, materials and construction methods can be readily approved.

A residential building on bushfire-prone land, the code states, must be designed and constructed to “reduce the risk” of ignition from a bushfire, appropriate to the risk from bushfire flames, burning embers, radiant heat and intensity of the bushfire attack.

The risk to which a building is expected to be exposed depends on the individual site and conditions such as vegetation type and density, and slope of land. Properties are assessed and given a “Bushfire Attack Level” (BAL) rating by inspectors.

There are six BAL levels that classify the severity of potential exposure to bushfire. The highest – BAL FZ – is for buildings exposed to an extreme risk, such as a house surrounded by trees that could produce direct contact from flames.

Lower BAL levels take into account risks from burning debris, ember attack and radiant heat. The lowest deems the risk insufficient to warrant any specific construction requirements.

Construction details for each BAL cover building elements such as floors, walls, roofs, doors, windows, vents, roof drainage systems, verandahs, and water and gas supply pipes. For example, fire-resistant timber may be required for floor framing, or windows may be required to use toughened glass.

Balancing competing interests

Are the requirements of the National Construction Code good enough?

If the aim is to minimise the number of buildings damaged or destroyed in extreme fire events, the answer is no.

But that’s not the aim. Like most government regulation, the code requirements are about balancing competing interests.

All building regulations are subject to cost-benefit analysis. They must demonstrate a “net cost benefit” to the community – that the cost of compliance will be less than the benefit delivered to the general community.

It’s a cold calculation about the risk and potential cost of homes being destroyed in bushfires versus the more certain costs involved in requiring all homes to be built to more stringent building codes.

Government policy treats potential property loss as a matter for owners to address through property insurance. There’s no reason to expect this to change any time soon.

Learning from experience

If the cost of building destruction in bushfires turned out to be greater than the cost of more stringent building requirements, there would be a strong rationale to improve the regulations. This is why post-fire analysis is so important.

A prime example is the royal commission into the causes and costs of the Black Saturday fires.

The commission’s final report made a number of recommendations for changes to the National Construction Code. These included new provisions to:

  • make protection from ember attack a performance requirement
  • address the design and construction of private (underground) bushfire emergency shelters
  • include design and construction requirements for non-residential buildings, such as schools and aged-care centres, in bushfire-prone areas.

All governments agreed to the first two recommendations, which were promptly implemented in the National Construction Code (in 2010).

The recommendation about non-residential building was not implemented at the time because governments considered that planning laws would not allow these types of buildings to be built in a bushfire-prone area.

However, the 2019-2020 business plan of the Australian Building Codes Board (which administers the National Construction Code, includes a “bushfire provisions for non-residential buildings” project, so it is reasonable to expect changes to the code in future.




Read more:
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This season’s fires may also provide impetus for other changes to the construction code. One key factor that will be worthy of research is the age of the buildings destroyed.

Depending on how many homes lost were built after 2010, it might be argued that changes made after the 2009 Victorian fire have been insufficient to keep up with evolving conditions.The Conversation

Raymond William Loveridge, Adjunct Professor – School of Built Environment, University of Technology Sydney

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Our buildings aren’t made to keep out bushfire smoke. Here’s what you can do



On many days Canberra has the worst air quality of any major international city. Even in the best buildings it’s not good.
NARENDRA SHRESTHA/EPA

Geoff Hanmer, UNSW

In early December 2019, a Sheffield Shield cricket match between NSW and Queensland was played in bushfire smoke so thick that the ball was at times invisible to the spectators.

Since then, the rest of us have become far more aware of the hazards of bushfire smoke, and authorities have become more active in reminding us how dangerous it can be, especially during exercise. A standard piece of advice is to “spend more time indoors”.

But does it work?

Up until this year, with bushfire smoke lasting only a few days, it was good advice, especially for buildings that rely on recirculated and filtered mechanical ventilation complying with Australian Standard 1668 Part 2.

These buildings include shopping malls, cinemas, hospitals, larger offices and some of the buildings in some universities.

It’s fine in cinemas, for a while…

Unfortunately, if smoke is particularly thick or goes on for more than a few days, these systems get overwhelmed, which is why smoke detectors in many commercial and institutional buildings have been setting off fire alarms and why the National Gallery of Australia in Canberra was closed on Sunday and Monday.

Most houses or apartments are designed to be “naturally ventilated” under the National Construction Code, which means every habitable room has an openable window or a vent.

Closing the windows, vents and doors will reduce the “air change rate”, which is the number of times an hour the air in the room is replaced by outside air.

Less fine in homes

Regrettably, unless there is no wind, CSIRO research suggests most Australian houses are quite leaky by international standards, mainly because of leaky windows and doors.

Wall ventilator.
Source: GIYGreenItYourself

Houses and apartments built before 1970 are the worst. Many have fixed ventilators just below the ceiling level, a hangover from regulations designed to ensure gas lighting did not cause asphyxiation.

These ventilators are now unnecessary and can be safely blocked off.

In normal times some leakage is not a bad thing, as it offers protection against internal air pollution from volatile organic compounds in furniture and building materials and cooking, smoking and heating.

But these are not normal times.

The length and severity of bushfire smoke appears to be unprecedented.

With bushfire smoke persisting for days or weeks, the standard advice to be “indoors” is less effective. While houses and apartments might be useful for keeping smoke out for a few days or so, they become less effective over time, depending on how leaky they are.

Take care

Before embarking on a campaign to seal leaks with draft stripping and duct tape, please ensure your that your range hood is vented directly to outside (preferably with an automatic flap) that if you smoke you do it outside, and that your furniture and fabrics are low in volatile organic compounds, which arechemicals that release vapor at room temperature.

If your house is sealed up, do not use a gas cooker without an externally vented range hood or use an unflued gas heater at any time.

Ensure your vacuum cleaner has a HEPA (high-efficiency particulate air) filter.

Remember duct tape or masking tape is likely to be very difficult to remove if you leave it on for more than a few days and may damage painted surfaces.

Air conditioners aren’t much help

Even if your house is well sealed, it’s likely the air in it will become similar in quality to the air outside over a period of several days. While the air change rate in your house might be low, it will not be zero.

A recirculating air conditioner, such as a split system, will make you cooler but most domestic air conditioning filters are not capable of removing the very small particles in bushfire smoke – the ones that most make it dangerous.

Evaporative air conditioners or window mounted air conditioners that draw air in from outside will actually make indoor conditions worse.

Some recirculating air purifier systems will remove bushfire smoke, but they can be expensive to buy and run.

Air purifiers can help, but they’re expensive

To be effective against bushfire smoke, the air purifier needs to be fitted with a HEPA filter.

The performance of many purifiers is less than stellar, but a CHOICE survey published just before Christmas is a useful starting point.

CHOICE is preparing a bigger test of more models which it will publish in March 2020.

It brought forward the test of six of them because of the fires.




Read more:
From face masks to air purifiers: what actually works to protect us from bushfire smoke?


All six remove bushfire smoke particles with various degrees of efficiency, but their coverage area is limited. The Blueair 205 performed the best.

For people in an at-risk group, the use of an air purifier in a sealed-up house or apartment should help.

The only certain solution for someone suffering from smoke or concerned about its long-term impacts is to go to a building that has a recirculating HEPA filtered air conditioning system or move to a location where the air quality is better.The Conversation

Geoff Hanmer, Adjunct Lecturer in Architecture, UNSW

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Putting homes in high-risk areas is asking too much of firefighters


Mark Maund, University of Newcastle; Kim Maund, University of Newcastle, and Thayaparan Gajendran, University of Newcastle

The impacts of the bushfires that are overwhelming emergency services in New South Wales and Queensland suggest houses are being built in areas where the risks are high. We rely heavily on emergency services to protect people and property, but strategic land-use planning can improve resilience and so help reduce the risk in the first place. This would mean giving more weight to considering bushfire hazards at the earliest stages of planning housing supply.

The outstanding dedication of emergency agencies such as the NSW Rural Fire Service and Queensland Fire and Emergency Service is obvious in their efforts to save lives and properties despite the increasing intensity of fires. However, strategic land-use planning could help reduce the risks by being more responsive to such changes in hazards.




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Comprehensive management of bushfire risk should include a strategic planning focus on reducing the pressures on emergency services and communities. We may have to rethink land-use planning approaches that prove inadequate to deal with the increasing intensity and unpredictability of natural hazards.

Strategic planning policies and practices provide the opportunity to be more attentive to changes in bushfire hazards in particular. Planning decisions that fail to do this may leave communities exposed and heavily reliant on emergency services during a disaster.

Planning to build resilience

The Australian government has identified land-use planning as a key step in managing natural hazards. In 2011, the Council of Australian Governments declared:

Locating new or expanding existing settlements and infrastructure in areas exposed to unreasonable risk is irresponsible.

The increasing intensity of hazards associated with climate change makes strategic planning even more relevant. Land-use planners could help greatly with building resilience by placing natural hazards at the top of their assessment criteria.




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Coordinating land-use planning reforms is itself a challenge. Planning in Australia involves many policies, institutions, professions and decision-makers. Policies and processes differ depending on the state or territory.

Furthermore, planners must reconcile the demand for residential land from population growth and the need to protect the environment. Deciding where to locate housing is often fraught with complexity, so the process needs expert early input from relevant scientific communities and emergency services.

Anticipate risk to reduce it

Land-use planning offers an opportunity in the earliest phase of development to manage the combined pressures of population growth, urban expansion, increasing density and risks of natural hazards.

When rezoning land for residential development, many issues have to be considered. These include environmental sustainability, demand for housing and the location of existing buildings and infrastructure, as well as natural hazards. It’s a complex and intricate process, but clearly the strategic planning stage is the first opportunity to minimise exposure to bushfire risk.

Existing policy and processes may defer the detailed review of bushfire risk and other natural hazards to development stages after land has been rezoned. There’s a case for policy to increase the importance attached to bushfire hazards at this early stage.

Ultimately, strategic planners aim to locate settlements away from risk of natural hazards. However, bushfires continue to have disastrous impacts on people and properties. Ongoing demand for housing may add pressure to build in areas exposed to risk.

Settlements are pushing into undeveloped areas that are more likely to be exposed to bushfire risk. The role of strategic land-use planning then becomes even more critical. The devastation we have seen this month shows why this risk must be given the highest priority in land-use planning, particularly when zoning land as residential.




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Key steps to reform planning

The increasing intensity of bushfires points to a need to rethink planning processes and mitigation strategies to reduce exposure to such hazards before they arise. This will help ease the burden on emergency services of managing a disaster when it happens. We can’t ignore the opportunities to minimise the risks at the early stages of land-use planning. Key steps include:The Conversation

  • a policy review to mandate natural hazards, including bushfire risk, as one of the highest priorities in policy, with an objective framework for making land-use decisions
  • mandatory consultation with relevant science disciplines to model natural hazard risks when land is considered for rezoning
  • involve emergency services in the strategic planning phase to help minimise future risk.

Mark Maund, PhD Candidate, School of Architecture and Built Environment, University of Newcastle; Kim Maund, Discipline Head – Construction Management, School of Architecture and Built Environment, University of Newcastle, and Thayaparan Gajendran, Associate Professor, School of Architecture and Built Environment, University of Newcastle

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Houses for a warmer future are currently restricted by Australia’s building code



Australians need better solutions for coping with the warmer climate of the future (and present).
TRACEY NEARMY/AAP

Anir Kumar Upadhyay, UNSW; Chris Lockhart Smith, UNSW, and Krishna Munsami, UNSW

Australian houses use significantly more electricity to stay warm or cool than estimated during the design stage.

To design a new house in Australia, the building needs to meet the national construction code. One way to do this is by using software to simulate the building’s thermal efficiency, to see if it meets the minimum requirements of the national house energy scheme. The scheme divides Australia geographically into 69 different climate zones and requires new houses to be thermally appropriate for their environment.




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Unfortunately, this software does not properly take into account our warming weather. Our recent report found the climate assumptions used by the government drastically underestimate the length and heat of summers in the near future.

In fact, buildings that perform best for heat waves predicted by 2030 are actually banned by the government’s building code. We urgently need to update our building codes to cope with our changing climate.

Understand the future local climate

We took Richmond in New South Wales as an example to understand the effect a changing climate might have on building performance. By taking predictions from CSIRO’s medium greenhouse gas emissions scenario, we analysed Richmond’s likely weather for every week of 2030.

The future outlook, shown below, is strikingly different from the weather files used to determine whether houses meet the minimum thermal performance requirement of the National Construction Code. In 2030, Richmond will experience a warm period almost four times longer than predicted by the official weather file.


Author provided

Design for the future

Based on the future climate scenario, the design strategy for buildings in Richmond should focus on well shaded and insulated buildings to avoid any heat gain in the warm period, but should also harness sunlight to warm up the indoors in the cool period.

The warm period will last from December to March, when keeping the house cool is the priority. Passive solar heating, such as northern windows and well-insulated walls, floor and ceilings, are important during the May to September cool months, while direct ventilation is largely all that’s needed during the mostly comfortable April and October to November.

To test how houses will perform in a hotter future, we modelled a house in Richmond using AccuRate software. We found a design and construction solution that performed well (achieving 7.6 stars out of 10) for the 2030 scenario failed to meet a heating threshold that is legally required in NSW. In effect, the house that makes the most sense for the immediate future, could not be built.

These thresholds for heating and cooling are based on assumptions that are out of step with current conditions, let alone the future. Between 2016 and 2018 Richmond’s annual average temperature was 17.8℃, whereas the NatHERS weather file assumes it to be 16.7℃. This difference is set to increase.

In a 2019 amendment, the National Construction Code adopted NSW’s approach to heating and cooling thresholds to other climate zones in other states. The heating threshold puts a restraint on designing buildings that are optimised to mitigate extreme heat events.

This highlights the limitation of out-of-date climate files, and the current regulation that acts as a barrier to developing energy efficient designs for a future warmer climate.

Build to perform

A 2013 CSIRO study found that houses with higher star ratings using more energy in summer.

One of the reasons is the trade-offs on the thermal performance of one building component against another in the Nationwide House Energy Rating Scheme (NatHERS) software. For example, a window without shading on the western façade is acceptable in a NatHERS simulation, whereas the same window would not be allowed if a glazing calculator developed by the National Construction Code were used to demonstrate the thermal performance of a house.

Other issues are trade workmanship, such whether a building is airtight. Airtightness in residential buildings is ignored in the national construction code. However, considerable energy savings can be achieved if a house can be made airtight.


Author provided

Similarly, missing or displaced insulation in the ceiling, as shown above, can cause significant discomfort and additional heating and cooling costs. We all, from builders to homeowners, need to understand insulation must be carefully installed and cannot be moved later, or even well designed buildings will become inefficient.

Windows are the main option for ventilating most houses. However, if you live in a high-pollution or noisy area, or in a place with very little wind, open windows might not be desirable or practical. Consequently, households may not be getting enough fresh air to maintain a healthy indoor environment. A mechanical ventilation system, which uses little energy, is an ideal alternative.




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The current weather files and heating thresholds used to develop minimum building standards are inadequate for our warming climate. Our report presents a framework for designing and building houses that consider climate change. We hope to see further research on other Australian population centres, so we can develop a comprehensive overview to help us build energy efficient and healthy houses for the future.The Conversation

Anir Kumar Upadhyay, Lecturer in Built Environment, UNSW; Chris Lockhart Smith, Director – ecodweller, UNSW, and Krishna Munsami, PhD student, UNSW

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Australia’s still building 4 in every 5 new houses to no more than the minimum energy standard


Trivess Moore, RMIT University; Michael Ambrose, CSIRO, and Stephen Berry, University of South Australia

New housing in Australia must meet minimum energy performance requirements. We wondered how many buildings exceeded the minimum standard. What our analysis found is that four in five new houses are being built to the minimum standard and a negligible proportion to an optimal performance standard.

Before these standards were introduced the average performance of housing was found to be around 1.5 stars. The current minimum across most of Australia is six stars under the Nationwide House Energy Rating Scheme (NatHERS).

This six-star minimum falls short of what is optimal in terms of environmental, economic and social outcomes. It’s also below the minimum set by many other countries.




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There have been calls for these minimum standards to be raised. However, many policymakers and building industry stakeholders believe the market will lift performance beyond minimum standards and so there is no need to raise these.

What did the data show?

We wanted to understand what was happening in the market to see if consumers or regulation were driving the energy performance of new housing. To do this we explored the NatHERS data set of building approvals for new Class 1 housing (detached and row houses) in Australia from May 2016 (when all data sets were integrated by CSIRO and Sustainability Victoria) to December 2018.

Our analysis focuses on new housing in Victoria, South Australia, Western Australia, Tasmania and the ACT, all of which apply the minimum six-star NatHERS requirement. The other states have local variations to the standard, while New South Wales uses the BASIX index to determine the environmental impact of housing.

The chart below shows the performance for 187,320 house ratings. Almost 82% just met the minimum standard (6.0-6.4 star). Another 16% performed just above the minimum standard (6.5-6.9 star).

Only 1.5% were designed to perform at the economically optimal 7.5 stars and beyond. By this we mean a balance between the extra upfront building costs and the savings and benefits from lifetime building performance.

NatHERS star ratings across total data set for new housing approvals, May 2016–December 2018.
Author provided

The average rating is 6.2 stars across the states. This has not changed since 2016.

Average NatHERS star rating for each state, 2016-18.
Author provided

The data analysis shows that, while most housing is built to the minimum standard, the cooler temperate regions (Tasmania, ACT) have more houses above 7.0 stars compared with the warm temperate states.

NatHERS data spread by state.
Author provided

The ACT increased average performance each year from 6.5 stars in 2016 to 6.9 stars in 2018. This was not seen in any other state or territory.

The ACT is the only region with mandatory disclosure of the energy rating on sale or lease of property. The market can thus value the relative energy efficiency of buildings. Providing this otherwise invisible information may have empowered consumers to demand slightly better performance.




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We are paying for accepting a lower standard

The evidence suggests consumers are not acting rationally or making decisions to maximise their financial well-being. Rather, they just accept the minimum performance the building sector delivers.

Higher energy efficiency or even environmental sustainability in housing provides not only significant benefits to the individual but also to society. And these improvements can be delivered for little additional cost.




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The fact that these improvements aren’t being made suggests there are significant barriers to the market operating efficiently. This is despite increasing awareness among consumers and in the housing industry about the rising cost of energy.

Eight years after the introduction of the six-star NatHERS minimum requirement for new housing in Australia, the results show the market is delivering four out of five houses that just meet this requirement. With only 1.5% designed to 7.5 stars or beyond, regulation rather than the economically optimal energy rating is clearly driving the energy performance of Australian homes.

Increasing the minimum performance standard is the most effective way to improve the energy outcomes.

The next opportunity for increasing the minimum energy requirement will be 2022. Australian housing standards were already about 2.0 NatHERS stars behind comparable developed countries in 2008. If mandatory energy ratings aren’t increased, Australia will fall further behind international best practice.

If we continue to create a legacy of homes with relatively poor energy performance, making the transition to a low-energy and low-carbon economy is likely to get progressively more challenging and expensive. Recent research has calculated that a delay in increasing minimum performance requirements from 2019 to 2022 will result in an estimated A$1.1 billion (to 2050) in avoidable household energy bills. That’s an extra 3 million tonnes of greenhouse gas emissions.




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Our research confirms the policy proposition that minimum house energy regulations based on the Nationwide House Energy Rating Scheme are a powerful instrument for delivering better environmental and energy outcomes. While introducing minimum standards has significantly lifted the bottom end of the market, those standards should be reviewed regularly to ensure optimal economic and environmental outcomes.The Conversation

Trivess Moore, Lecturer, RMIT University; Michael Ambrose, Research Team Leader, CSIRO, and Stephen Berry, Research fellow, University of South Australia

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Floating cities: the future or a washed-up idea?



Oceanix, a proposed floating city, has captured the attention of the UN.
OCEANIX/BIG-Bjarke Ingels Group

Brydon T. Wang, Queensland University of Technology

Humans have a long history of living on water. Our water homes span the fishing villages in Southeast Asia, Peru and Bolivia to modern floating homes in Vancouver and Amsterdam. As our cities grapple with overcrowding and undesirable living situations, the ocean remains a potential frontier for sophisticated water-based communities.

The United Nations has expressed support for further research into floating cities in response to rising sea levels and to house climate refugees. A speculative proposal, Oceanix City, was unveiled in April at the first Round Table on Sustainable Floating Cities at UN headquarters in New York.

Life on a floating city, Oceanix.
OCEANIX/BIG-Bjarke Ingels Group

The former tourism minister of French Polynesia, Marc Collins Chen, and architecture studio BIG advanced the proposal. Chen is involved with the Seasteading Institute, which is seeking to develop autonomous city-states floating in the shallow waters of “host nations”.

While this latest proposal has gained UN attention, it is an old idea we have repeatedly returned to over the past 70 years with little success. In fact, the Oceanix City proposal has not reached the same level of technical sophistication as previous models.




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A brief history of floating cities

The architecture community was fascinated with marine utopias between the 1950s and ’70s. The technological optimism of this period led architects to consider whether we could build settlements in inhospitable places like the polar regions, the deserts and on the sea.

Plan for Tokyo Bay by Kenzo Tange, 1960.
Wikimedia

The Japanese Metabolists put forward incredible projects such as Kenzo Tange’s 1960 Tokyo Bay Plan and the marine city proposals of Kikutake and Kurokawa.

In the West, Buckminster Fuller proposed Triton City, which would be connected to the mainland via bridges. Archigram, a neofuturistic architectural group, proposed underwater sea farms.

These proposals were directed at solving the impending urban crises of overpopulation and pressures on land-based resources. Many were even sophisticated enough to be patented.

The arc of this global architectural discussion was captured during the first UN Habitat conference (“Habitat I”) in Vancouver in 1976. In many ways, the UN has returned to the Vancouver Declaration from Habitat I to “[adopt] bold, meaningful and effective human settlement policies and spatial planning strategies” and to treat “human settlements as an instrument and object of development”.

We are seeing a pivoting that began in 2008 with Vincent Callebaut’s “Lilypad” – a “floating ecopolis for ecological refugees”.

Where floating cities were once dismissed as too far-fetched, the concept has been repackaged and is re-emerging into public consciousness. This time in a more politically viable state – as a means of addressing the climate emergency.




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The technology and types of floating city structures

No floating settlements have ever been created on the high seas. Current offshore engineering is concerned with how cities can locate infrastructure, such as airports, nuclear power stations, bridges, oil storage facilities and stadiums, in shallow coastal environments rather than in deep international waters.

Two main types of very large floating structures (VLFS) technology can be used to carry the weight of a floating settlement.

The first, pontoon structures, are flat slabs suitable for floating in sheltered waters close to shore.

The second, semi-submersible structures (such as oil rigs), comprise platforms that are elevated on columns off the water surface. These can be located in deep waters. Potentially, oil rigs could be repurposed for such floating cities in international waters.

Transforming oil rigs into liveable structures. Ku Yee Kee and Hor Sue-Wern’s entry in the 2011 eVolo Skyscraper Competition.
Ku Yee Kee & Hor Sue-Wern/ eVolo, CC BY

Oceanix City is based on the pontoon structure. This would restrict it to shallower waters with breakwaters to limit the impacts of waves. This sort of structure could serve as an extension of a coastal city, as a life raft for island communities inundated by rising waters, or to provide mobile essential services to residents of flood-prone slums.




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Sovereign floating cities and micronations

While some early marine utopian proposals were responses to emerging urban issues, many proposals conceptualised “seaborne leisure colonies”. These communities would be independent city-states allowing inhabitants to circumvent tax laws or restrictions on medical research in their own countries.

This sort of floating city was conceived of as a micronation with sovereignty and ability to provide citizenship to its occupants. The example was set by the Principality of Sealand, off the coast of Britain.

The Principality of Sealand is a micronation situated on Roughs Tower, a platform off the coast of Britain.
Ryan Lackey/Flickr, CC BY

None of these proposals have succeeded. Even modern attempts such as the Freedom Ship and the Seasteading Institute’s plans for an autonomous floating settlement under French Polynesian jurisdiction have stalled. A recent attempt at creating a sovereign micronation (seastead) off Thailand led to its proponents becoming fugitives, potentially facing the death penalty.




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A viable project?

Technology is not a barrier to floating cities in international waters. Advances in technology enable us to create structures for habitation in deep sea waters. These schemes have never really taken off because of political and commercial barriers.

While this time round proponents are packaging floating cities in a more politically viable concept as a life raft for climate refugees, commercial barriers remain. Apart from the UN, few organisation have the economic and political influence or reason to deliver a satellite floating city in the ocean.

In my view, the future of ocean cities is in technology campuses and in tourism. Given the significant risk of a community in extreme isolation in international waters, the solution to bringing people together in mid-ocean requires us to think about what connects us: technology, work and play. In these three elements we see, perhaps, the two lowest-hanging fruits (or the most buoyant of possibilities) for ocean cities.

The first is in floating tech campuses where large technology companies set up floating data centres and campuses in international waters. Situated outside national jurisdictions, these campuses could circumvent increasingly onerous privacy regimes or offer innovative technological services without having to negotiate regulatory barriers.

The second prospect is a return to the seaborne leisure colonies of the past. Companies like Disney could expand on their cruise offerings to build floating theme parks. These resorts could be sited in international waters or hosted by coastal cities.

Given our fascination with living on water, even if Oceanix City does not suceed, it won’t be long before we see another floating city proposal. And if we get the mix of social, political and commercial drivers right, we might just find ourselves living on one.The Conversation

The Disney Cruise Line could potentially develop seaborne leisure colonies in future.
Diego Villuendas Pellicero/Flickr, CC BY-NC

Brydon T. Wang, Research Assistant and PhD Candidate, Queensland University of Technology

This article is republished from The Conversation under a Creative Commons license. Read the original article.