Why do you want to build an energy efficient and sustainable home? Is it because you want to save on energy bills?
Or is your main driver to reduce your carbon footprint and live lightly on this planet?
If your aim is to reduce your carbon footprint, while reducing your energy bills, of course. Then you have to consider the operation carbon footprint. As well as the carbon footprint of your construction. Of the materials used for your home.
To reduce the operational carbon footprint, building a passive house (passivhaus) is a great start.
The Passive House Standard are rigorous, but voluntary standard for energy efficiency in a building. Which reduces the building’s ecological footprint. It results in ultra-low energy buildings that require little to no energy for space heating or cooling. Even for the coldest and hottest parts of the world. Given you a guaranteed performance.
The Passive house standard is one holistic construction certification standard. It looks at the actual performance of a house, rather than just on paper. Which is a big problem with the current energy rating scheme in Australia. Meaning the client will have a guaranteed well performing home.
One of the key elements of the passive house standard is the thermal bridge free construction. Which requires the avoidance of structural steel in the construction. In order to avoid structural steel first floor walls need to sit on top of ground floor walls. If upper walls are stepped in to create articulation the wall and roof structure would require structural steel. Which will create thermal bridges. And hence decrease the thermal efficiency of the house.
But another factor to consider here is the carbon footprint of the construction. The construction footprint contributes to up to 50% of our carbon emissions. And we believe it is important to reduce our carbon footprint where possible. If first floor walls are stepped in to create articulation the surface area of the building increases. There is more external wall area, another roof is created. And hence, more construction materials and resources are needed. On top of the steel. Which increases the carbon footprint further.
Often when you build a new home or when you do an extension a town planning permit may be required. This means you have to send plans to your local council. And they will review your design against local and state planning regulations and policies.
As a general rule, council does not like sheer walls. They don’t like first floor walls sitting on top of ground floor walls. What they want to see is articulation.
When you next drive past a town house development. Have a look. Can you see how the first-floor walls are stepped in? Creating what is often referred to as a wedding cake style.
While it is not a law that first floor walls must be stepped in. And if you don’t need a planning permit this can be done without a problem. But, as soon as you need a planning permit. Council will most likely request that you change your design.
As mentioned above, stepping in the first-floor walls will not only compromise the efficiency of your home. But also increase the construction cost and the carbon footprint of the materials used.
So, what options do you have?
Well, this is the million-dollar question. We often face this challenge with council. And often end up with some sort of compromise. Where we step in some of the walls. And propose elements to create a visual articulation on other walls wherever we can.
For instance, you can add roof sections or pergolas. These can visually separate double storey walls. Or you can split surfaces by mixing up materials and finishes.
Sadly, there is no guarantee that council will support your efforts. One can only try and explain to council the sustainable objective. And why we try to keep the dwelling as compact as possible.
Do you have any questions about articulation? Or how to tackle council? Please get in touch.