Global Warming Impact on Pergolas and Verandahs​

Global Warming Impact on Pergolas and Verandahs

Global Warming Impact on Decks

We have been asked a number of time recently on what impact the Global Warming Impact on Pergolas and Verandahs​ will likely be for home owners.

Firstly we would like to acknowledge that Global Warming is real and there is evidence in our industry that we need to consider harsher conditions when making Verandahs and Pergolas that will last to the harsher conditions expected in Melbourne.

Our manufacturers and to some extent our competitors are acknowledging that change is necessary and that the impact moving forward is real and already evident.

What we do know

The Australian Government is already taking about and commenting on the potential impact of global warming and climate change on housing in Australia. Current and Future impacts of climate change on housing.

Some Expected Changes

Outlined in the Your Home website by the Australian Government. We can expect…

  • about 1°C of warming, resulting in more heatwaves (CSIRO and BOM 2007; Australian Academy of Science 2010)
  • up to 20% more months of drought (CSIRO and BOM 2007)
  • up to 25% increase in days of very high or extreme fire danger (CSIRO and BOM 2007)
  • increases in storm surges and severe weather events (CSIRO and BOM 2007; Australian Academy of Science 2010)
  • a sea level rise of about 15cm (Australian Academy of Science 2010).

Planning for climate change impacts

Good design for a changing climate is design that is flexible enough to adapt to prevailing conditions while optimising the occupants’ comfort and the house’s livability (see Design for climate).

When considering design or redesign of a home, ask the following questions:

  • What are the climate variables that could affect the building?
  • Will climate change impacts affect the site and the building?
  • What are the likely consequences to the home in the event of extreme weather?

Strategies set in place early will reduce future costs; linking actions into build, renovation or repair cycles will also minimise costs (Major and O’Grady 2010; Snow and Prasad 2011). Decisions can be made without accurate predictions of future climate change. A range of plausible scenarios combining climate projections will help to explore potential outcomes and risks (Snow and Prasad 2011).

Seek professional advice (e.g. from your architect or designer) before acting. Once the options have been identified, compare them against other factors:

  • How effective will the option be over the life of the house? Is it flexible enough to respond to climate conditions?
  • How practical is the option, and is it easy and relatively inexpensive to maintain?
  • Is it compatible with the existing dwelling?
  • Are there other benefits, or undesired side effects, that arise from the option?

Building flexibility into the process means that changing climate conditions can be taken into account (Major and O’Grady 2010). The design incorporates pathways for adaptation in the future, which can be taken as needed without too much additional expense. Examples of such ‘flexible adaptation pathways’ include:

  • ensuring that there is enough space in your land to include extra water storage for changing water availability
  • building more substantial footings under a deck so that it can easily take the weight of a roof if in future more shade is needed around the house as temperatures rise.

It may not be necessary to build a fortress-like home — one that is capable of withstanding all impacts while complying with building regulations. It might be an option to build a home that is:

  • of limited life to minimise financial outlay, i.e. a home which the owner is willing to lose, either in part or whole, for example in areas where extreme storms are likely to occur
  • transportable, or modular, and able to be moved and used elsewhere if the site becomes unsuitable, for example due to sea level rise.

The best adaptation actions are win-win or low/no regret, i.e. they may offer other benefits. For example, concrete floors which have high thermal mass have the potential to keep the home warm or cool, and also recover well should the house be flooded (Snow and Prasad 2011).

Adaptation and mitigation can complement each other and together reduce the risks. Conversely, ensure these actions do not undermine each other. For example, adaptation actions for one climate change impact could cause a home to be less well adapted for other impacts (‘maladaptation’) or could also create a home that is less livable for changing lifestyle needs (see Design for climate). These effects should be avoided or perhaps negated through design or materials choices, as shown in the table.

Examples of unintended results of adaptation actions and possible solutions


Potential unintended result

Example of solution

Ensuring roofs are designed to cope with high intensity rainfall events

May increase roof complexity, which increases the chance that embers will lodge during bushfires

Ensure roof design is simple and minimises the likelihood that embers will be caught in the roof

Installing and using a large air conditioner to cope with hotter temperatures

Will produce more greenhouse gases because of increased power needs

Incorporate passive design or use alternative power sources

Insulating homes and sealing against airflow to minimise loss of heat for energy efficiency

Could change the capacity of the dwelling to lose heat in summer

Design house to allow increased airflow during the relevant periods

Raising floor levels to avoid flooding

May disturb acid sulphate soils by changing the level of the watertable if solid fill is used

Do not use solid fill in areas that may have acid sulphate soils


Could reduce accessibility for the less physically able

Consider including ramps or other options

Adaptive strategies for building design

Adaptive strategies should be considered for these climate change variables:

  • temperature increase and heatwaves
  • bushfires
  • cyclones and extreme wind
  • severe thunderstorms and high intensity rainfall events
  • flooding
  • sea level rise and storm surge
  • low rainfall.

Many of the options outlined below are from Snow and Prasad (2011). Seek advice from a professional, e.g. an architect or designer, before making changes to the design or redesign of your home.

Talk to Totally Outdoors

We welcome discussions around building and considering for planning of climate change on your home investment projects with Pergolas and Verandahs. 

Our Location:

Factory 1 26-28 Abbott Road Hallam – come and see our undercover display centre

Contact Us

Telephone: (BH) 03 9796 6899

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Totally Outdoors – Pergolas and Verandahs