Showing posts with label residential building design. Show all posts
Showing posts with label residential building design. Show all posts

Wednesday 7 February 2024

Climate Change Australia 2024 - the elephant in the room that all three tiers of Australian government are failing to address - the indoor heat in metropolitan & regional urban areas

 

Although science had been warning about a marked global land-sea surface warming trend for longer, it wasn't until around 1972 that a global conversation about anthropomorphic global warming or climate change began.


This conversation began to formalize under the auspices of the United Nations and by 1988 its member states, including Australia, were broad brush level aware of the timeline and scale science was predicting.


Over the years since, science has been pointing at Australia when calculating where the impacts of climate change would first be felt in a recognizable and widespread way.


Between 1983 and 2022 there had been four Liberal Party prime ministers leading federal Coalition governments setting national policy and legislation (across a combined of total of just over 20 years) and four Labor prime minister leading federal Labor governments setting national policy and legislation (across a combined of total of just over 18 years).


Over that same 39 year time frame New South Wales has had six Liberal premiers and six Labor premiers.


During all these years it was only between 2007 to 2012 that an Australian federal government could be seen as genuinely attempting (and often failing) to set the nation on the path to reduce the nation's CO2-e emissions.


Since 22 May 2022 Australia has once more a Labor prime minister and federal government setting national policy and legislation for the last 625 days, as well as another NSW Labor state premier and government setting state policy and legislation for the last 316 days.


One of the early Albanese Government decisions was to create the Department of Climate Change, Energy, the Environment and Water (DCCEEW), with the ministers having portfolio responsibility identified as Chris Bowen, Minister for Climate Change and Energy & Tanya Plibersek, Minister for the Environment and Water.


The webpage transcript excerpt set at the end of this post is one aspect of information shared online by the DCCEEW which is barely mentioned by the media or NSW federal & state members of their respective parliaments.


It is certainly not information which has translated into action at state or local government planning level in any meaningful way in New South Wales.


This was New South Wales between 1 January to 5 February 2024:






Click on images to enlarge


This was the Australian Bureau of Meteorology NSW Heatwave Map on 3 February 2024:













Look around your town or village and count how many houses built in the last 20 years which appear to have been constructed to a design that will be likely to cope with the predicted increasing number of  days per year of maximum heatwave conditions of 35°C and over.


If your count is so low in the streets near you that it shocks, perhaps now is the time to insist that at federal, state and local government level a new mandatory building code be implemented which requires as part of development consent conditions:  (i) passive building design; (ii) indoor temperature-mitigating building material use; and (iv) subdivisions layouts and streetscapes which avoid heat island effects.


Department of Climate Change, Energy, the Environment and Water (est. July 2022), Your Home, "Australia's Guide To Environmentally Adaptable Homes", excerpt:


Designing for climate change

You can design or renovate your home to take into account the sort of climate impacts you expect to be most relevant for your area.


Temperature increase and heatwaves

One of the main expected effects of global climate change across Australia is increasing temperatures and a greater number of extremely hot days (CSIRO and BOM 2020). Australian households need to consider how they can adapt to maintain comfort, manage household energy costs, and reduce the risk of heat stress and heat-related illness and mortality.


The need to keep your home cool during the summer months will be greater. On the other hand, there should be less need to heat the home in winter. Good passive design can lessen the need to rely on air-conditioners and help to capture the savings from lowered heating energy needs.


Consider the impact of increased numbers of heatwaves in your region. Over the past several decades, heatwaves have increased in duration, frequency and intensity in many parts of Australia (Steffen et al. 2019). New homes are not typically constructed to provide maximum protection from heatwaves as standard. In urban areas, tree canopy cover is decreasing as development intensifies. Urban areas may be particularly prone to heatwave conditions because of the ‘heat island’ effect, in which the abundance of heat-absorbing materials such as concrete, and lack of vegetation, increases their temperature compared with the surrounding area. Good tree canopy and other vegetation around your home and neighbourhood can reduce the impact of the urban heat island effect (see Green roofs and walls).


In addition, electricity demand rises sharply during heatwaves because of increased air-conditioning usage, contributing to blackouts. Excess peak demand drives up electricity prices, making air-conditioning use during heatwaves too expensive for some low-income households.


The NCC heating and cooling load limits under the NatHERS compliance pathway assist to keep homes at a comfortable temperature year-round. The load limits have been developed using the 2022 NatHERS climate files based on historical weather data, and the requirements change depending on which climate zone the home is built in.....


Tip

In the early stage of design, decide if your home will be air-conditioned, naturally ventilated, or a combination. This will affect further design decisions including the type and level of insulation.


Overall, adapting to cope with increased temperatures requires appropriate heat-resistant building materials and design. Key design strategies include:


  • orientating living rooms appropriately and using shading to minimise summer heat gain

  • using thermal mass appropriately

  • locating bedrooms in the coolest part of the building and using insulation, shading and so on to ensure comfortable temperatures for sleeping

  • providing opportunities for night-time ventilation, including natural ventilation and mechanical systems

  • using light-coloured roofs and ‘cool roof’ technology (specially designed roofing materials and coatings with high solar reflectance and thermal emittance)

  • creating a ‘cool retreat’ – a portion of the dwelling designed to provide comfort during heatwave periods. This could be a shaded, ventilated room or basement that is well insulated and able to be closed off from warmer parts of the house so it can be efficiently air-conditioned

  • using cooling technologies powered by renewable energy

  • using landscape to decrease the need for cooling (for example, by shading, channelling cool breezes, lowering surface temperatures).

Refer to Passive cooling for more information on cooling design strategies....     [my yellow highlighting]