Building for Extreme Weather: The Pressure on Residential Architecture
We look at three case studies of how local architectures are responding to global climate challenges
This November, the World Meterological Organisation released its provisional State of Climate report 2021 ahead of COP26 in Glasgow. Pointing to alarming sea level increases and noting that the last seven years were the warmest on record, the report warns that greenhouse gas emissions are pushing our planet into crisis as planetary warming fuels extreme weather around the world.
In a press release, WMO Secretary-General Professor Petteri Taalas outlined some of the bizarre weather events we’ve witnessed in recent years. “Extreme events are the new norm. It rained – rather than snowed – for the first time on record at the peak of the Greenland ice sheet. Canadian glaciers suffered rapid melting. A heatwave in Canada and adjacent parts of the USA pushed temperatures to nearly 50°C in a village in British Columbia. Death Valley, California, reached 54.4°C during one of multiple heatwaves in the southwestern USA, whilst many parts of the Mediterranean experienced record temperatures. The exceptional heat was often accompanied by devastating fires. Months’ worth of rainfall fell in the space of hours in China and parts of Europe saw severe flooding, leading to dozens of casualties and billions in economic losses.”
In a press release, WMO Secretary-General Professor Petteri Taalas outlined some of the bizarre weather events we’ve witnessed in recent years. “Extreme events are the new norm. It rained – rather than snowed – for the first time on record at the peak of the Greenland ice sheet. Canadian glaciers suffered rapid melting. A heatwave in Canada and adjacent parts of the USA pushed temperatures to nearly 50°C in a village in British Columbia. Death Valley, California, reached 54.4°C during one of multiple heatwaves in the southwestern USA, whilst many parts of the Mediterranean experienced record temperatures. The exceptional heat was often accompanied by devastating fires. Months’ worth of rainfall fell in the space of hours in China and parts of Europe saw severe flooding, leading to dozens of casualties and billions in economic losses.”
Image from the World Meteorological Organisation
In India, temperatures are soaring and urban areas are frequently inundated with rainwater. “Because of climate change, now there are periods ranging from 3 to 30 days where there is deluge-level flooding or extreme heat waves in the Indian subcontinent,” says architect and urban planner Madhav Raman, co-founder of Anagram Architects.
A study published in the International Journal of Climatology has warned of even more severe heat waves in north-western, central and south-central regions. Frequent storm surges, cyclones and cloudburst phenomena are being observed of late not only in vulnerable areas, such as the Himalayan foothills and coastal peninsular regions but also in dense urban centres like Delhi and Mumbai, leading to loss of life and property.
In India, temperatures are soaring and urban areas are frequently inundated with rainwater. “Because of climate change, now there are periods ranging from 3 to 30 days where there is deluge-level flooding or extreme heat waves in the Indian subcontinent,” says architect and urban planner Madhav Raman, co-founder of Anagram Architects.
A study published in the International Journal of Climatology has warned of even more severe heat waves in north-western, central and south-central regions. Frequent storm surges, cyclones and cloudburst phenomena are being observed of late not only in vulnerable areas, such as the Himalayan foothills and coastal peninsular regions but also in dense urban centres like Delhi and Mumbai, leading to loss of life and property.
The Delhi home by Anagram Architects has thick floors and walls, voluminous spaces for thermal stacking, swivelling panels that double as louvres and vertical slits to aid ventilation during extreme heat.
A team of scientists at the Potsdam Institute for Climate Impact Research (PIK) warned in a recent preprint of a study of even more erratic and alarmingly stronger monsoons. The problem is exacerbated by lifestyle and building practices. Raman says, “The ground water is drying out, and then we are cementing the run off [over areas of water-absorbent soil].” Therefore, water coming into cities through storm bursts take it to an apocalyptic level.
Historically, Indian vernacular architecture has used many ‘design tools’ from its kitty for climate resilience and to fight the country’s hot weather. Central courtyards, pitched roofs with verandahs and latticed screens (jalis) for walls are some of the many elements that continue to be designed into rural and urban Indian homes alike. To combat the rise in heat intensity, “architects in urban areas are now increasingly using passive cooling technologies like double-wall construction, solar panels, green insulation, cool roofs, low-energy building design, energy-efficient double-glazed windows, and use of rammed-earth bricks and drywalls,” says architect Kanhai Gandhi, co-founder of KNS Architects.
A team of scientists at the Potsdam Institute for Climate Impact Research (PIK) warned in a recent preprint of a study of even more erratic and alarmingly stronger monsoons. The problem is exacerbated by lifestyle and building practices. Raman says, “The ground water is drying out, and then we are cementing the run off [over areas of water-absorbent soil].” Therefore, water coming into cities through storm bursts take it to an apocalyptic level.
Historically, Indian vernacular architecture has used many ‘design tools’ from its kitty for climate resilience and to fight the country’s hot weather. Central courtyards, pitched roofs with verandahs and latticed screens (jalis) for walls are some of the many elements that continue to be designed into rural and urban Indian homes alike. To combat the rise in heat intensity, “architects in urban areas are now increasingly using passive cooling technologies like double-wall construction, solar panels, green insulation, cool roofs, low-energy building design, energy-efficient double-glazed windows, and use of rammed-earth bricks and drywalls,” says architect Kanhai Gandhi, co-founder of KNS Architects.
In this home in Alibaug, India, designed by Architecture Brio, metal chains direct rainwater from a concealed gutter and storm-water pipes into a collection basin.
Practices such as increasing the height of the plinth and thoroughly waterproofing exterior and interior walls are being adopted to combat extreme rain. In a first, sP+a, a design firm in Mumbai, has designed a cantilevered building in a flood-prone area with a depression underneath, specifically built to catch excess rainwater, which is then directed to the water table. Raman says, “To address urban flooding in India, the whole water cycle of a home in a city needs to be planned in a simple, closed-loop system on a granular level. It’s key that on an individual level people look into resilience. There needs to be a basic contract between the local RWAs (Residents’ Welfare Associations) and their local zonal administrations to manage household water expulsion effectively.”
Practices such as increasing the height of the plinth and thoroughly waterproofing exterior and interior walls are being adopted to combat extreme rain. In a first, sP+a, a design firm in Mumbai, has designed a cantilevered building in a flood-prone area with a depression underneath, specifically built to catch excess rainwater, which is then directed to the water table. Raman says, “To address urban flooding in India, the whole water cycle of a home in a city needs to be planned in a simple, closed-loop system on a granular level. It’s key that on an individual level people look into resilience. There needs to be a basic contract between the local RWAs (Residents’ Welfare Associations) and their local zonal administrations to manage household water expulsion effectively.”
This house built near a river in Tokyo was designed keeping in mind evacuation and restoration in case of floods. The detached house, owned by a yoga instructor, has a ‘doma’ space – a transitional space between indoors and outdoors – which is used as a yoga studio, on the ground floor. The doma’s traditional earthen floor makes it easier to recover this part of the house in case the ground floor is damaged by water.
Planning for Floods and Their Aftermaths in Japan
Typhoons and heavy rains hitting Japan have become more intense than ever in recent years. According to the Japan Meteorological Agency, the average occurrence of hourly precipitation of 50 millimetres or more annually during the last 10 years (2011–2020) has increased about 1.5 times compared to the average number of annual occurrences during the 10 years of the statistical period of 1976–1985.
“As sea surface temperatures are rising due to global warming, typhoons tend to be more powerful than in the past,” says architect Masatoyo Ogasawara. “Along with ‘river flooding’, which happens when the river water overflows over the embankment due to heavy rain, ‘urban inundation’, in which heavy rainfall in urban areas overflows onto the ground, is also a characteristic of flood damage in Japan.” The Ministry of Land, Infrastructure, Transport and Tourism in Japan announced that damage caused by floods in 2019 was approximately 2.18 trillion yen, which is the largest ever caused by water damages other than tsunamis, since statistics began to be kept in 1958.
Planning for Floods and Their Aftermaths in Japan
Typhoons and heavy rains hitting Japan have become more intense than ever in recent years. According to the Japan Meteorological Agency, the average occurrence of hourly precipitation of 50 millimetres or more annually during the last 10 years (2011–2020) has increased about 1.5 times compared to the average number of annual occurrences during the 10 years of the statistical period of 1976–1985.
“As sea surface temperatures are rising due to global warming, typhoons tend to be more powerful than in the past,” says architect Masatoyo Ogasawara. “Along with ‘river flooding’, which happens when the river water overflows over the embankment due to heavy rain, ‘urban inundation’, in which heavy rainfall in urban areas overflows onto the ground, is also a characteristic of flood damage in Japan.” The Ministry of Land, Infrastructure, Transport and Tourism in Japan announced that damage caused by floods in 2019 was approximately 2.18 trillion yen, which is the largest ever caused by water damages other than tsunamis, since statistics began to be kept in 1958.
The living-dining room and kitchen are all located on the first floor, so they could still be used if the ground floor is damaged by flood.
According to Ogasawara, it is important to carefully study hazard maps and avoid building houses in high-risk areas in Japan. He also points out that there are basically four effective ways to deal with flood damage: raising the ground, raising the floor, enclosing the building and waterproofing the building.
Ogasawara says that the Japanese architectural community, such as the Architectural Institute of Japan, have started looking into how they could quickly restore a building after it has suffered flooding damage, and not only trying to prevent the damage in the first place. “By analysing the priorities of each room and planning them carefully, it is possible to build a house that can be restored quickly even if it is flooded,” says Ogasawara.
According to Ogasawara, it is important to carefully study hazard maps and avoid building houses in high-risk areas in Japan. He also points out that there are basically four effective ways to deal with flood damage: raising the ground, raising the floor, enclosing the building and waterproofing the building.
Ogasawara says that the Japanese architectural community, such as the Architectural Institute of Japan, have started looking into how they could quickly restore a building after it has suffered flooding damage, and not only trying to prevent the damage in the first place. “By analysing the priorities of each room and planning them carefully, it is possible to build a house that can be restored quickly even if it is flooded,” says Ogasawara.
When calamitous fires tore through Kangaroo Valley, NSW, in January 2020, Nick Turner’s home was directly in their path. But having planned for the inevitable when constructing his bushfire-resilient home, he felt ready. His home has a robust off-grid power system, water tanks and is constructed out of bushfire-resistant materials.
Mitigating Bushfire Risk in Australia
In Australia, “extremely high temperatures and extreme fire weather causing bushfires are two of the biggest extreme weather challenges,” says Julie Firkin, director of Julie Firkin Architects. Firkin’s design for a bushfire-resistant house was featured by the Bushfire Homes Service following the Black Saturday bushfires in 2009, and Firkin has taught extensively on the subject. “In addition, we are facing more extreme rainfall events causing floods, increasing tropical cyclone intensity in northern areas and more droughts in southern areas. We also need to consider that extreme sea levels are occurring more often, causing coastal erosion and inundation.”
“Architecture in Victoria [a state in Australia] has definitely responded to the threat of bushfire after the 2009 Black Saturday bushfires with the introduction of a new Australian Standard AS 3959–2009 (which is country-wide) for construction of buildings in bushfire-prone areas. This standard sets out a way to quantify the risk of bushfire on a site. It then lays out corresponding minimum construction standards that will mitigate the level of bushfire risk,” Firkin says. There are also state-specific provisions. “Since 2017, changes to the Bushfire Management Overlay (Victoria Planning Provision 44.06) have come into effect, which will substantially change whether it is possible to build new homes at all in some bushfire-prone areas. For example, on a small site adjacent to the large area of a national park, it may not be possible to achieve the necessary setback from a potential flame source which could engulf a building, and this is now considered an unacceptable risk to human life,” she says.
Mitigating Bushfire Risk in Australia
In Australia, “extremely high temperatures and extreme fire weather causing bushfires are two of the biggest extreme weather challenges,” says Julie Firkin, director of Julie Firkin Architects. Firkin’s design for a bushfire-resistant house was featured by the Bushfire Homes Service following the Black Saturday bushfires in 2009, and Firkin has taught extensively on the subject. “In addition, we are facing more extreme rainfall events causing floods, increasing tropical cyclone intensity in northern areas and more droughts in southern areas. We also need to consider that extreme sea levels are occurring more often, causing coastal erosion and inundation.”
“Architecture in Victoria [a state in Australia] has definitely responded to the threat of bushfire after the 2009 Black Saturday bushfires with the introduction of a new Australian Standard AS 3959–2009 (which is country-wide) for construction of buildings in bushfire-prone areas. This standard sets out a way to quantify the risk of bushfire on a site. It then lays out corresponding minimum construction standards that will mitigate the level of bushfire risk,” Firkin says. There are also state-specific provisions. “Since 2017, changes to the Bushfire Management Overlay (Victoria Planning Provision 44.06) have come into effect, which will substantially change whether it is possible to build new homes at all in some bushfire-prone areas. For example, on a small site adjacent to the large area of a national park, it may not be possible to achieve the necessary setback from a potential flame source which could engulf a building, and this is now considered an unacceptable risk to human life,” she says.
For nine hours, a team battled to save Turner’s property. They kept a ‘halo’ watering system running that was connected to three water tanks, which saturated everything around the house as it was engulfed in embers. Turner’s careful forward planning and the team’s efforts meant the house survived, while the area beyond its perimeter was destroyed.
The Australian design community favours using non-combustible materials for construction (brick, concrete, steel and fibre-cement sheet), designing homes with uncomplicated exterior forms (easier to maintain and keep clear of flammable debris), and using shade structures and shutters to protect the home from radiant heat.
“I would encourage potential home builders to investigate if there is a BMO (Bushfire Management Overlay) before purchasing land, and to work with an architect who is familiar with the regulations that are going to impact on your design. I believe it is possible to achieve beautiful design solutions in which we can appreciate the natural surroundings while also being safe,” Firkin says.
A Shift Towards Resilient Design
Battered by heat, fire and flood – global themes iterating in manifold local manifestations – residential architecture around the world is being put to the test. As extreme climate events push design and home construction policies to evolve, the onus is on individual homeowners, residential and design communities, and government decision makers to make informed choices for safe and climate resilient home construction.
Read more:
Global Snapshot: Thought-Provoking Sustainability Solutions
Life in Architecture: Madhav Raman
Tell us:
What changes would you like to see in the building of your home so that it can more efficiently combat extreme weather?
The Australian design community favours using non-combustible materials for construction (brick, concrete, steel and fibre-cement sheet), designing homes with uncomplicated exterior forms (easier to maintain and keep clear of flammable debris), and using shade structures and shutters to protect the home from radiant heat.
“I would encourage potential home builders to investigate if there is a BMO (Bushfire Management Overlay) before purchasing land, and to work with an architect who is familiar with the regulations that are going to impact on your design. I believe it is possible to achieve beautiful design solutions in which we can appreciate the natural surroundings while also being safe,” Firkin says.
A Shift Towards Resilient Design
Battered by heat, fire and flood – global themes iterating in manifold local manifestations – residential architecture around the world is being put to the test. As extreme climate events push design and home construction policies to evolve, the onus is on individual homeowners, residential and design communities, and government decision makers to make informed choices for safe and climate resilient home construction.
Read more:
Global Snapshot: Thought-Provoking Sustainability Solutions
Life in Architecture: Madhav Raman
Tell us:
What changes would you like to see in the building of your home so that it can more efficiently combat extreme weather?
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As we enter an era of unpredictable anomalous weather, the design conversation is evolving. There is a shift from a singular focus on sustainability to also building climate change resilience. The Resilient Design Institute defines it as the “intentional design of buildings, landscapes, communities, and regions in order to respond to natural and manmade disasters and disturbances”. It means limiting dependency on water, sewerage and waste disposal needs, as well as preparing homes to withstand and bounce back from extreme weather events.
To achieve this, a wide range of solutions are being explored around the world – from robust vernacular building practices to optimising on-site renewable energy resources, upgrading building codes, using new materials and incorporating passive design techniques and eco-conscious active systems. Here, we look at case studies of how steps towards resilience are being taken in three local contexts in the face of extreme weather events.
The Twin Challenges of Heating and Flooding in India’s Urban Areas
As the planet warms up, our cities are getting even hotter, and that affects our homes and our ability to survive in a fast-changing urban environment. The United Nations Environment Programme recently published a comprehensive, first-of-its-kind guide to proven sustainable cooling strategies for urban centres (called Beating the Heat: A Sustainable Cooling Handbook for Cities) that focuses on cities for good reason. Cities are already urban heat islands that have warmer temperatures – by over 5 degrees Celsius – than their surrounding areas. This is because cities trap a greater amount of heat through their dense design, structures and networks. Heat is absorbed by common building materials such as asphalt and cement, and also radiated from buildings and motor vehicles. The effect is exacerbated by a constantly depleting green cover. The book couldn’t be more timely: temperatures in urban areas are rising twice as fast as the global average warming rate, according to their research.