Sustainable Design
When it comes down to it, the design of a home is the most important thing in order to maximise efficiency and overall sustainability.
There are many factors involved with making a home sustainable in terms of design and each home has its own principles based on local environment conditions, the lot alignment (i.e. does the place face north, south, east or west) and a multitude of others.
Questions are very important and they should always be directed to an architect that specialises in sustainable design or a professional building consultant in the field.
Enter your question in the field below and our professional consultants will answer:
Questions and Answers:
Q. Would just like to know a list of the prominent sustainable materials commonly used in building a basic home?
A. I think the issue is that there isnt a list of prominent sustainable materials commonly used in a basic home. Of course depending upon how you define sustainable.
Responsibly harvested timber is - but how much of it is responsible harvested? Timber is a renewable recourse that is low in embodied energy and if the forests are harvested responsibly then this is perhaps the single most sustainable material we have. And if we use this as out benchmark, the only way is down.
Like I said - It also depend on how you define sustainable.
Bricks and concrete will both last a very long time, however are also both very high in embodied energy. Considering that our buildings produce as much as 40% of Australia's emissions, materials need to be low in embodied energy, or offset economically to be 'sustainable'.
Sustainable materials and products that are commonly used and benefit the householder and the environment include:
Timber - floors, frames, trusses, doors, architraves, skirtings etc Insulation Solar hot water systems Photovoltaic panels for many areas of Australia (not common though) Most Rain Water tanks Most Grey water systems Some energy efficient windows (aluminium is very high in embodied energy) I guess you could say that plasterboard is sustainable, some low-toxic paints are.
A great way to build a sustainable house is in kit form because there is very little waste, and we can easily waste 10% of materials on many building sites.
If there was a system in place where we could offset the embodied energy in our homes I guess you could almost say materials like bricks and concrete could be sustainable. Just so you know a rough estimate in cost to offset emissions from the construction of a new home is around $5,000. Compared to the cost to offset a flight from Hobart to Melbourne on Virgin for around $2.00
A very good resource to compare materials is ecospecifier - do a google search.
I don't think this is the answer you may have been expecting - But perhaps because it is such a good and important question, and that we don't have a straightforward answer is highlighting part of the problem we are facing.
All the best.
For more info, you can what could well be the best value Guide on sustainable housing via download at:
http://www.sunrisehomes.net.au/bloogoocms/asp/print_template.asp?articleID=161
All the best!
Libe Chacos
2007 Australian GreenSmart Professional of The Year Sunrise Homes Tasmania Pty Ltd
23 Alfreds Garden, Kingston Tasmania 7050
p: 03 6229 4447
f: 03 6229 4470
m: 0439 337 445
libe@sunrisehomes.net.au
http://sunrisehomes.net.au
Q. What are the fundamentals I should know about when it comes to sustainable design of a new home? James, NSW
A. Designing a good sustainable home can be a daunting exercise with a lot of terminology that you may not understand, so I will try and give you a ‘laymans’ guide to the fundamentals.
First thing to consider is what is called passive design. Passive design can be outlined as follows:
- design your home to suit the climate where it is to be built, building a lightweight pavilion style house would not be appropriate in an area such as the Snowy Mountains
- design you home to make maximum use of the best orientation available on your site. That means locating living areas to North so they enjoy the winter sun and locating windows and rooms to allow for cross ventilation in the summer.
- provide good shading to all windows. The idea is to allow the winter sun when it is low in the sky to enter your home and provide free warming, and in the summer when it is higher in the sky, to have shading that prevents the sun from entering your home.
- insulate your house well, don’t scrimp on it. Insulation is one of the most cost effective ways to try and improve your comfort in your home.
- depending on where you house is located, thermal mass is a way of improving the comfort levels in your home. Put simply, thermal mass is a dense material such and concrete or brick that is used to store warmth in the winter, and cool in the summer. In winter it works by storing warmth from either direct exposure to the sun or from heating within the home during the day, and releasing it back into the house at night. In summer it works in the reverse way, by avoiding exposing the thermal mass to a heat source during the day, night breezes are allowed to pass over or past the thermal mass drawing out the stored heat.
- avoid using standard 3mm glass in your windows. This is almost as good as having cling film in your windows. Heat and warmth will pass straight through and either cool your house down in the winter or heat it up in the summer. Look to use either double glazing or a low – e higher performance glass to try and prevent this from happening. Windows are an often overlooked aspect of house design so really consider the options carefully. Have a look at the WERS website which is the national window energy rating scheme website.
Second thing to consider is your water usage. Use minimum 3 star rated tap ware and water fixtures including dishwashers and washing machines. Look to collect as much rainwater as possible and use this to flush your toilets and in your washing machines. Also, consider a grey water system for the water from your shower, basins etc. This water can be easily treated and re-used on your garden. And finally if you want to go all they way, recycle your black water from your toilet, which when treated can be re-used in your garden.
Third thing to consider is your energy use. Use low energy use fixtures such and washing machines and dishwashers. Lighting should all be the new compact fluorescent fittings. Several manufactures make these as down lights, so if that is what you want, then there is no reason not to install them. They use around 80% less energy than the standard fitting and last up to 8 times as long. Hot water heating uses around 30% of your household energy, so to almost wipe that out, consider putting in a solar hot water system. And off course, you can go even further and look to produce your own energy on site through a Photovoltaic or mini wind power system.
Forth thing relates to heating and cooling. If you have done all of the above things well, then in many parts of Australia you may not need any supplementary heating or cooling. For heating there are many options from wood burning heaters, to gas heaters, to hydronic heating systems. It is a case of investigating the best option for your circumstances. Cooling, in my opinion can be dealt with entirely with the passive items outlined above. If done well you shouldn’t require any supplementary cooling.
Fifth thing is to think carefully about the materials you propose to use for construction. Try and use materials that are local to your site and don’t have to travel huge distances. Consider the environmental impact of the materials you proposed to use. Dense materials such as concrete and brick are high in what is called embodied energy. Embodied energy is the total energy consumed in the manufacture and life of that material. Consider that concrete production alone is responsible for around 5% of the worlds man made carbon dioxide emissions. Minimise the waste produced during construction and look to try and re-use or recycle materials.
And, lastly but not the least, think about the impact of your house and building on the biodiversity and environment in the area.
A good source of online information is the ‘your home’ website, have a look at it here.
Darryn Parkinson
Your Abode, Ph 02 9973 2756, www.yourabode.com.au
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